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katex-spec.js (69779B)

---

 /* eslint max-len:0 */
 /* global beforeEach: false */
 /* global jasmine: false */
 /* global expect: false */
 /* global it: false */
 /* global describe: false */
 
 const buildMathML = require("../src/buildMathML");
 const buildTree = require("../src/buildTree");
 const katex = require("../katex");
 const ParseError = require("../src/ParseError");
 const parseTree = require("../src/parseTree");
 const Options = require("../src/Options");
 const Settings = require("../src/Settings");
 const Style = require("../src/Style");
 
 const defaultSettings = new Settings({});
 const defaultOptions = new Options({
     style: Style.TEXT,
     size: "size5",
 });
 
 const _getBuilt = function(expr, settings) {
     const usedSettings = settings ? settings : defaultSettings;
     const parsedTree = parseTree(expr, usedSettings);
     const rootNode = buildTree(parsedTree, expr, usedSettings);
 
     // grab the root node of the HTML rendering
     const builtHTML = rootNode.children[1];
 
     // Remove the outer .katex and .katex-inner layers
     return builtHTML.children[2].children;
 };
 
 /**
  * Return the root node of the rendered HTML.
  * @param expr
  * @param settings
  * @returns {Object}
  */
 const getBuilt = function(expr, settings) {
     const usedSettings = settings ? settings : defaultSettings;
     expect(expr).toBuild(usedSettings);
     return _getBuilt(expr, settings);
 };
 
 /**
  * Return the root node of the parse tree.
  * @param expr
  * @param settings
  * @returns {Object}
  */
 const getParsed = function(expr, settings) {
     const usedSettings = settings ? settings : defaultSettings;
 
     expect(expr).toParse(usedSettings);
     return parseTree(expr, usedSettings);
 };
 
 const stripPositions = function(expr) {
     if (typeof expr !== "object" || expr === null) {
         return expr;
     }
     if (expr.lexer && typeof expr.start === "number") {
         delete expr.lexer;
         delete expr.start;
         delete expr.end;
     }
     Object.keys(expr).forEach(function(key) {
         stripPositions(expr[key]);
     });
     return expr;
 };
 
 const parseAndSetResult = function(expr, result, settings) {
     try {
         return parseTree(expr, settings || defaultSettings);
     } catch (e) {
         result.pass = false;
         if (e instanceof ParseError) {
             result.message = "'" + expr + "' failed " +
                 "parsing with error: " + e.message;
         } else {
             result.message = "'" + expr + "' failed " +
                 "parsing with unknown error: " + e.message;
         }
     }
 };
 
 beforeEach(function() {
     jasmine.addMatchers({
 
         toParse: function() {
             return {
                 compare: function(actual, settings) {
                     const usedSettings = settings ? settings : defaultSettings;
 
                     const result = {
                         pass: true,
                         message: "'" + actual + "' succeeded parsing",
                     };
                     parseAndSetResult(actual, result, usedSettings);
                     return result;
                 },
             };
         },
 
         toNotParse: function() {
             return {
                 compare: function(actual, settings) {
                     const usedSettings = settings ? settings : defaultSettings;
 
                     const result = {
                         pass: false,
                         message: "Expected '" + actual + "' to fail " +
                             "parsing, but it succeeded",
                     };
 
                     try {
                         parseTree(actual, usedSettings);
                     } catch (e) {
                         if (e instanceof ParseError) {
                             result.pass = true;
                             result.message = "'" + actual + "' correctly " +
                                 "didn't parse with error: " + e.message;
                         } else {
                             result.message = "'" + actual + "' failed " +
                                 "parsing with unknown error: " + e.message;
                         }
                     }
 
                     return result;
                 },
             };
         },
 
         toBuild: function() {
             return {
                 compare: function(actual, settings) {
                     const usedSettings = settings ? settings : defaultSettings;
 
                     const result = {
                         pass: true,
                         message: "'" + actual + "' succeeded in building",
                     };
 
                     expect(actual).toParse(usedSettings);
 
                     try {
                         _getBuilt(actual, settings);
                     } catch (e) {
                         result.pass = false;
                         if (e instanceof ParseError) {
                             result.message = "'" + actual + "' failed to " +
                                 "build with error: " + e.message;
                         } else {
                             result.message = "'" + actual + "' failed " +
                                 "building with unknown error: " + e.message;
                         }
                     }
 
                     return result;
                 },
             };
         },
 
         toParseLike: function(util, baton) {
             return {
                 compare: function(actual, expected) {
                     const result = {
                         pass: true,
                         message: "Parse trees of '" + actual +
                             "' and '" + expected + "' are equivalent",
                     };
 
                     const actualTree = parseAndSetResult(actual, result);
                     if (!actualTree) {
                         return result;
                     }
                     const expectedTree = parseAndSetResult(expected, result);
                     if (!expectedTree) {
                         return result;
                     }
                     stripPositions(actualTree);
                     stripPositions(expectedTree);
                     if (!util.equals(actualTree, expectedTree, baton)) {
                         result.pass = false;
                         result.message = "Parse trees of '" + actual +
                             "' and '" + expected + "' are not equivalent";
                     }
                     return result;
                 },
             };
         },
 
     });
 });
 
 describe("A parser", function() {
     it("should not fail on an empty string", function() {
         expect("").toParse();
     });
 
     it("should ignore whitespace", function() {
         const parseA = stripPositions(getParsed("    x    y    "));
         const parseB = stripPositions(getParsed("xy"));
         expect(parseA).toEqual(parseB);
     });
 });
 
 describe("An ord parser", function() {
     const expression = "1234|/@.\"`abcdefgzABCDEFGZ";
 
     it("should not fail", function() {
         expect(expression).toParse();
     });
 
     it("should build a list of ords", function() {
         const parse = getParsed(expression);
 
         expect(parse).toBeTruthy();
 
         for (let i = 0; i < parse.length; i++) {
             const group = parse[i];
             expect(group.type).toMatch("ord");
         }
     });
 
     it("should parse the right number of ords", function() {
         const parse = getParsed(expression);
 
         expect(parse.length).toBe(expression.length);
     });
 });
 
 describe("A bin parser", function() {
     const expression = "+-*\\cdot\\pm\\div";
 
     it("should not fail", function() {
         expect(expression).toParse();
     });
 
     it("should build a list of bins", function() {
         const parse = getParsed(expression);
         expect(parse).toBeTruthy();
 
         for (let i = 0; i < parse.length; i++) {
             const group = parse[i];
             expect(group.type).toEqual("bin");
         }
     });
 });
 
 describe("A rel parser", function() {
     const expression = "=<>\\leq\\geq\\neq\\nleq\\ngeq\\cong";
 
     it("should not fail", function() {
         expect(expression).toParse();
     });
 
     it("should build a list of rels", function() {
         const parse = getParsed(expression);
         expect(parse).toBeTruthy();
 
         for (let i = 0; i < parse.length; i++) {
             const group = parse[i];
             expect(group.type).toEqual("rel");
         }
     });
 });
 
 describe("A punct parser", function() {
     const expression = ",;\\colon";
 
     it("should not fail", function() {
         expect(expression).toParse();
     });
 
     it("should build a list of puncts", function() {
         const parse = getParsed(expression);
         expect(parse).toBeTruthy();
 
         for (let i = 0; i < parse.length; i++) {
             const group = parse[i];
             expect(group.type).toEqual("punct");
         }
     });
 });
 
 describe("An open parser", function() {
     const expression = "([";
 
     it("should not fail", function() {
         expect(expression).toParse();
     });
 
     it("should build a list of opens", function() {
         const parse = getParsed(expression);
         expect(parse).toBeTruthy();
 
         for (let i = 0; i < parse.length; i++) {
             const group = parse[i];
             expect(group.type).toEqual("open");
         }
     });
 });
 
 describe("A close parser", function() {
     const expression = ")]?!";
 
     it("should not fail", function() {
         expect(expression).toParse();
     });
 
     it("should build a list of closes", function() {
         const parse = getParsed(expression);
         expect(parse).toBeTruthy();
 
         for (let i = 0; i < parse.length; i++) {
             const group = parse[i];
             expect(group.type).toEqual("close");
         }
     });
 });
 
 describe("A \\KaTeX parser", function() {
     it("should not fail", function() {
         expect("\\KaTeX").toParse();
     });
 });
 
 describe("A subscript and superscript parser", function() {
     it("should not fail on superscripts", function() {
         expect("x^2").toParse();
     });
 
     it("should not fail on subscripts", function() {
         expect("x_3").toParse();
     });
 
     it("should not fail on both subscripts and superscripts", function() {
         expect("x^2_3").toParse();
 
         expect("x_2^3").toParse();
     });
 
     it("should not fail when there is no nucleus", function() {
         expect("^3").toParse();
         expect("_2").toParse();
         expect("^3_2").toParse();
         expect("_2^3").toParse();
     });
 
     it("should produce supsubs for superscript", function() {
         const parse = getParsed("x^2")[0];
 
         expect(parse.type).toBe("supsub");
         expect(parse.value.base).toBeDefined();
         expect(parse.value.sup).toBeDefined();
         expect(parse.value.sub).toBeUndefined();
     });
 
     it("should produce supsubs for subscript", function() {
         const parse = getParsed("x_3")[0];
 
         expect(parse.type).toBe("supsub");
         expect(parse.value.base).toBeDefined();
         expect(parse.value.sub).toBeDefined();
         expect(parse.value.sup).toBeUndefined();
     });
 
     it("should produce supsubs for ^_", function() {
         const parse = getParsed("x^2_3")[0];
 
         expect(parse.type).toBe("supsub");
         expect(parse.value.base).toBeDefined();
         expect(parse.value.sup).toBeDefined();
         expect(parse.value.sub).toBeDefined();
     });
 
     it("should produce supsubs for _^", function() {
         const parse = getParsed("x_3^2")[0];
 
         expect(parse.type).toBe("supsub");
         expect(parse.value.base).toBeDefined();
         expect(parse.value.sup).toBeDefined();
         expect(parse.value.sub).toBeDefined();
     });
 
     it("should produce the same thing regardless of order", function() {
         const parseA = stripPositions(getParsed("x^2_3"));
         const parseB = stripPositions(getParsed("x_3^2"));
 
         expect(parseA).toEqual(parseB);
     });
 
     it("should not parse double subscripts or superscripts", function() {
         expect("x^x^x").toNotParse();
 
         expect("x_x_x").toNotParse();
 
         expect("x_x^x_x").toNotParse();
 
         expect("x_x^x^x").toNotParse();
 
         expect("x^x_x_x").toNotParse();
 
         expect("x^x_x^x").toNotParse();
     });
 
     it("should work correctly with {}s", function() {
         expect("x^{2+3}").toParse();
 
         expect("x_{3-2}").toParse();
 
         expect("x^{2+3}_3").toParse();
 
         expect("x^2_{3-2}").toParse();
 
         expect("x^{2+3}_{3-2}").toParse();
 
         expect("x_{3-2}^{2+3}").toParse();
 
         expect("x_3^{2+3}").toParse();
 
         expect("x_{3-2}^2").toParse();
     });
 
     it("should work with nested super/subscripts", function() {
         expect("x^{x^x}").toParse();
         expect("x^{x_x}").toParse();
         expect("x_{x^x}").toParse();
         expect("x_{x_x}").toParse();
     });
 });
 
 describe("A subscript and superscript tree-builder", function() {
     it("should not fail when there is no nucleus", function() {
         expect("^3").toBuild();
         expect("_2").toBuild();
         expect("^3_2").toBuild();
         expect("_2^3").toBuild();
     });
 });
 
 describe("A parser with limit controls", function() {
     it("should fail when the limit control is not preceded by an op node", function() {
         expect("3\\nolimits_2^2").toNotParse();
         expect("\\sqrt\\limits_2^2").toNotParse();
         expect("45 +\\nolimits 45").toNotParse();
     });
 
     it("should parse when the limit control directly follows an op node", function() {
         expect("\\int\\limits_2^2 3").toParse();
         expect("\\sum\\nolimits_3^4 4").toParse();
     });
 
     it("should parse when the limit control is in the sup/sub area of an op node", function() {
         expect("\\int_2^2\\limits").toParse();
         expect("\\int^2\\nolimits_2").toParse();
         expect("\\int_2\\limits^2").toParse();
     });
 
     it("should allow multiple limit controls in the sup/sub area of an op node", function() {
         expect("\\int_2\\nolimits^2\\limits 3").toParse();
         expect("\\int\\nolimits\\limits_2^2").toParse();
         expect("\\int\\limits\\limits\\limits_2^2").toParse();
     });
 
     it("should have the rightmost limit control determine the limits property " +
         "of the preceding op node", function() {
 
         let parsedInput = getParsed("\\int\\nolimits\\limits_2^2");
         expect(parsedInput[0].value.base.value.limits).toBe(true);
 
         parsedInput = getParsed("\\int\\limits_2\\nolimits^2");
         expect(parsedInput[0].value.base.value.limits).toBe(false);
     });
 });
 
 describe("A group parser", function() {
     it("should not fail", function() {
         expect("{xy}").toParse();
     });
 
     it("should produce a single ord", function() {
         const parse = getParsed("{xy}");
 
         expect(parse.length).toBe(1);
 
         const ord = parse[0];
 
         expect(ord.type).toMatch("ord");
         expect(ord.value).toBeTruthy();
     });
 });
 
 describe("An implicit group parser", function() {
     it("should not fail", function() {
         expect("\\Large x").toParse();
         expect("abc {abc \\Large xyz} abc").toParse();
     });
 
     it("should produce a single object", function() {
         const parse = getParsed("\\Large abc");
 
         expect(parse.length).toBe(1);
 
         const sizing = parse[0];
 
         expect(sizing.type).toEqual("sizing");
         expect(sizing.value).toBeTruthy();
     });
 
     it("should apply only after the function", function() {
         const parse = getParsed("a \\Large abc");
 
         expect(parse.length).toBe(2);
 
         const sizing = parse[1];
 
         expect(sizing.type).toEqual("sizing");
         expect(sizing.value.value.length).toBe(3);
     });
 
     it("should stop at the ends of groups", function() {
         const parse = getParsed("a { b \\Large c } d");
 
         const group = parse[1];
         const sizing = group.value[1];
 
         expect(sizing.type).toEqual("sizing");
         expect(sizing.value.value.length).toBe(1);
     });
 });
 
 describe("A function parser", function() {
     it("should parse no argument functions", function() {
         expect("\\div").toParse();
     });
 
     it("should parse 1 argument functions", function() {
         expect("\\blue x").toParse();
     });
 
     it("should parse 2 argument functions", function() {
         expect("\\frac 1 2").toParse();
     });
 
     it("should not parse 1 argument functions with no arguments", function() {
         expect("\\blue").toNotParse();
     });
 
     it("should not parse 2 argument functions with 0 or 1 arguments", function() {
         expect("\\frac").toNotParse();
 
         expect("\\frac 1").toNotParse();
     });
 
     it("should not parse a function with text right after it", function() {
         expect("\\redx").toNotParse();
     });
 
     it("should parse a function with a number right after it", function() {
         expect("\\frac12").toParse();
     });
 
     it("should parse some functions with text right after it", function() {
         expect("\\;x").toParse();
     });
 });
 
 describe("A frac parser", function() {
     const expression = "\\frac{x}{y}";
     const dfracExpression = "\\dfrac{x}{y}";
     const tfracExpression = "\\tfrac{x}{y}";
 
     it("should not fail", function() {
         expect(expression).toParse();
     });
 
     it("should produce a frac", function() {
         const parse = getParsed(expression)[0];
 
         expect(parse.type).toEqual("genfrac");
         expect(parse.value.numer).toBeDefined();
         expect(parse.value.denom).toBeDefined();
     });
 
     it("should also parse dfrac and tfrac", function() {
         expect(dfracExpression).toParse();
 
         expect(tfracExpression).toParse();
     });
 
     it("should parse dfrac and tfrac as fracs", function() {
         const dfracParse = getParsed(dfracExpression)[0];
 
         expect(dfracParse.type).toEqual("genfrac");
         expect(dfracParse.value.numer).toBeDefined();
         expect(dfracParse.value.denom).toBeDefined();
 
         const tfracParse = getParsed(tfracExpression)[0];
 
         expect(tfracParse.type).toEqual("genfrac");
         expect(tfracParse.value.numer).toBeDefined();
         expect(tfracParse.value.denom).toBeDefined();
     });
 
     it("should parse atop", function() {
         const parse = getParsed("x \\atop y")[0];
 
         expect(parse.type).toEqual("genfrac");
         expect(parse.value.numer).toBeDefined();
         expect(parse.value.denom).toBeDefined();
         expect(parse.value.hasBarLine).toEqual(false);
     });
 });
 
 describe("An over parser", function() {
     const simpleOver = "1 \\over x";
     const complexOver = "1+2i \\over 3+4i";
 
     it("should not fail", function() {
         expect(simpleOver).toParse();
         expect(complexOver).toParse();
     });
 
     it("should produce a frac", function() {
         let parse;
 
         parse = getParsed(simpleOver)[0];
 
         expect(parse.type).toEqual("genfrac");
         expect(parse.value.numer).toBeDefined();
         expect(parse.value.denom).toBeDefined();
 
         parse = getParsed(complexOver)[0];
 
         expect(parse.type).toEqual("genfrac");
         expect(parse.value.numer).toBeDefined();
         expect(parse.value.denom).toBeDefined();
     });
 
     it("should create a numerator from the atoms before \\over", function() {
         const parse = getParsed(complexOver)[0];
 
         const numer = parse.value.numer;
         expect(numer.value.length).toEqual(4);
     });
 
     it("should create a demonimator from the atoms after \\over", function() {
         const parse = getParsed(complexOver)[0];
 
         const denom = parse.value.numer;
         expect(denom.value.length).toEqual(4);
     });
 
     it("should handle empty numerators", function() {
         const emptyNumerator = "\\over x";
         const parse = getParsed(emptyNumerator)[0];
         expect(parse.type).toEqual("genfrac");
         expect(parse.value.numer).toBeDefined();
         expect(parse.value.denom).toBeDefined();
     });
 
     it("should handle empty denominators", function() {
         const emptyDenominator = "1 \\over";
         const parse = getParsed(emptyDenominator)[0];
         expect(parse.type).toEqual("genfrac");
         expect(parse.value.numer).toBeDefined();
         expect(parse.value.denom).toBeDefined();
     });
 
     it("should handle \\displaystyle correctly", function() {
         const displaystyleExpression = "\\displaystyle 1 \\over 2";
         const parse = getParsed(displaystyleExpression)[0];
         expect(parse.type).toEqual("genfrac");
         expect(parse.value.numer.value[0].type).toEqual("styling");
         expect(parse.value.denom).toBeDefined();
     });
 
     it("should handle \\textstyle correctly", function() {
         expect("\\textstyle 1 \\over 2")
             .toParseLike("\\frac{\\textstyle 1}{2}");
         expect("{\\textstyle 1} \\over 2")
             .toParseLike("\\frac{\\textstyle 1}{2}");
     });
 
     it("should handle nested factions", function() {
         const nestedOverExpression = "{1 \\over 2} \\over 3";
         const parse = getParsed(nestedOverExpression)[0];
         expect(parse.type).toEqual("genfrac");
         expect(parse.value.numer.value[0].type).toEqual("genfrac");
         expect(parse.value.numer.value[0].value.numer.value[0].value).toEqual("1");
         expect(parse.value.numer.value[0].value.denom.value[0].value).toEqual("2");
         expect(parse.value.denom).toBeDefined();
         expect(parse.value.denom.value[0].value).toEqual("3");
     });
 
     it("should fail with multiple overs in the same group", function() {
         const badMultipleOvers = "1 \\over 2 + 3 \\over 4";
         expect(badMultipleOvers).toNotParse();
 
         const badOverChoose = "1 \\over 2 \\choose 3";
         expect(badOverChoose).toNotParse();
     });
 });
 
 describe("A sizing parser", function() {
     const sizeExpression = "\\Huge{x}\\small{x}";
 
     it("should not fail", function() {
         expect(sizeExpression).toParse();
     });
 
     it("should produce a sizing node", function() {
         const parse = getParsed(sizeExpression)[0];
 
         expect(parse.type).toEqual("sizing");
         expect(parse.value).toBeDefined();
     });
 });
 
 describe("A text parser", function() {
     const textExpression = "\\text{a b}";
     const noBraceTextExpression = "\\text x";
     const nestedTextExpression =
         "\\text{a {b} \\blue{c} \\color{#fff}{x} \\llap{x}}";
     const spaceTextExpression = "\\text{  a \\ }";
     const leadingSpaceTextExpression = "\\text {moo}";
     const badTextExpression = "\\text{a b%}";
     const badFunctionExpression = "\\text{\\sqrt{x}}";
     const mathTokenAfterText = "\\text{sin}^2";
 
     it("should not fail", function() {
         expect(textExpression).toParse();
     });
 
     it("should produce a text", function() {
         const parse = getParsed(textExpression)[0];
 
         expect(parse.type).toEqual("text");
         expect(parse.value).toBeDefined();
     });
 
     it("should produce textords instead of mathords", function() {
         const parse = getParsed(textExpression)[0];
         const group = parse.value.body;
 
         expect(group[0].type).toEqual("textord");
     });
 
     it("should not parse bad text", function() {
         expect(badTextExpression).toNotParse();
     });
 
     it("should not parse bad functions inside text", function() {
         expect(badFunctionExpression).toNotParse();
     });
 
     it("should parse text with no braces around it", function() {
         expect(noBraceTextExpression).toParse();
     });
 
     it("should parse nested expressions", function() {
         expect(nestedTextExpression).toParse();
     });
 
     it("should contract spaces", function() {
         const parse = getParsed(spaceTextExpression)[0];
         const group = parse.value.body;
 
         expect(group[0].type).toEqual("spacing");
         expect(group[1].type).toEqual("textord");
         expect(group[2].type).toEqual("spacing");
         expect(group[3].type).toEqual("spacing");
     });
 
     it("should accept math mode tokens after its argument", function() {
         expect(mathTokenAfterText).toParse();
     });
 
     it("should ignore a space before the text group", function() {
         const parse = getParsed(leadingSpaceTextExpression)[0];
         // [m, o, o]
         expect(parse.value.body.length).toBe(3);
         expect(
             parse.value.body.map(function(n) { return n.value; }).join("")
         ).toBe("moo");
     });
 });
 
 describe("A color parser", function() {
     const colorExpression = "\\blue{x}";
     const newColorExpression = "\\redA{x}";
     const customColorExpression = "\\color{#fA6}{x}";
     const badCustomColorExpression = "\\color{bad-color}{x}";
 
     it("should not fail", function() {
         expect(colorExpression).toParse();
     });
 
     it("should build a color node", function() {
         const parse = getParsed(colorExpression)[0];
 
         expect(parse.type).toEqual("color");
         expect(parse.value.color).toBeDefined();
         expect(parse.value.value).toBeDefined();
     });
 
     it("should parse a custom color", function() {
         expect(customColorExpression).toParse();
     });
 
     it("should correctly extract the custom color", function() {
         const parse = getParsed(customColorExpression)[0];
 
         expect(parse.value.color).toEqual("#fA6");
     });
 
     it("should not parse a bad custom color", function() {
         expect(badCustomColorExpression).toNotParse();
     });
 
     it("should parse new colors from the branding guide", function() {
         expect(newColorExpression).toParse();
     });
 
     it("should have correct greediness", function() {
         expect("\\color{red}a").toParse();
         expect("\\color{red}{\\text{a}}").toParse();
         expect("\\color{red}\\text{a}").toNotParse();
         expect("\\color{red}\\frac12").toNotParse();
     });
 });
 
 describe("A tie parser", function() {
     const mathTie = "a~b";
     const textTie = "\\text{a~ b}";
 
     it("should parse ties in math mode", function() {
         expect(mathTie).toParse();
     });
 
     it("should parse ties in text mode", function() {
         expect(textTie).toParse();
     });
 
     it("should produce spacing in math mode", function() {
         const parse = getParsed(mathTie);
 
         expect(parse[1].type).toEqual("spacing");
     });
 
     it("should produce spacing in text mode", function() {
         const text = getParsed(textTie)[0];
         const parse = text.value.body;
 
         expect(parse[1].type).toEqual("spacing");
     });
 
     it("should not contract with spaces in text mode", function() {
         const text = getParsed(textTie)[0];
         const parse = text.value.body;
 
         expect(parse[2].type).toEqual("spacing");
     });
 });
 
 describe("A delimiter sizing parser", function() {
     const normalDelim = "\\bigl |";
     const notDelim = "\\bigl x";
     const bigDelim = "\\Biggr \\langle";
 
     it("should parse normal delimiters", function() {
         expect(normalDelim).toParse();
         expect(bigDelim).toParse();
     });
 
     it("should not parse not-delimiters", function() {
         expect(notDelim).toNotParse();
     });
 
     it("should produce a delimsizing", function() {
         const parse = getParsed(normalDelim)[0];
 
         expect(parse.type).toEqual("delimsizing");
     });
 
     it("should produce the correct direction delimiter", function() {
         const leftParse = getParsed(normalDelim)[0];
         const rightParse = getParsed(bigDelim)[0];
 
         expect(leftParse.value.mclass).toEqual("mopen");
         expect(rightParse.value.mclass).toEqual("mclose");
     });
 
     it("should parse the correct size delimiter", function() {
         const smallParse = getParsed(normalDelim)[0];
         const bigParse = getParsed(bigDelim)[0];
 
         expect(smallParse.value.size).toEqual(1);
         expect(bigParse.value.size).toEqual(4);
     });
 });
 
 describe("An overline parser", function() {
     const overline = "\\overline{x}";
 
     it("should not fail", function() {
         expect(overline).toParse();
     });
 
     it("should produce an overline", function() {
         const parse = getParsed(overline)[0];
 
         expect(parse.type).toEqual("overline");
     });
 });
 
 describe("A rule parser", function() {
     const emRule = "\\rule{1em}{2em}";
     const exRule = "\\rule{1ex}{2em}";
     const badUnitRule = "\\rule{1px}{2em}";
     const noNumberRule = "\\rule{1em}{em}";
     const incompleteRule = "\\rule{1em}";
     const hardNumberRule = "\\rule{   01.24ex}{2.450   em   }";
 
     it("should not fail", function() {
         expect(emRule).toParse();
         expect(exRule).toParse();
     });
 
     it("should not parse invalid units", function() {
         expect(badUnitRule).toNotParse();
 
         expect(noNumberRule).toNotParse();
     });
 
     it("should not parse incomplete rules", function() {
         expect(incompleteRule).toNotParse();
     });
 
     it("should produce a rule", function() {
         const parse = getParsed(emRule)[0];
 
         expect(parse.type).toEqual("rule");
     });
 
     it("should list the correct units", function() {
         const emParse = getParsed(emRule)[0];
         const exParse = getParsed(exRule)[0];
 
         expect(emParse.value.width.unit).toEqual("em");
         expect(emParse.value.height.unit).toEqual("em");
 
         expect(exParse.value.width.unit).toEqual("ex");
         expect(exParse.value.height.unit).toEqual("em");
     });
 
     it("should parse the number correctly", function() {
         const hardNumberParse = getParsed(hardNumberRule)[0];
 
         expect(hardNumberParse.value.width.number).toBeCloseTo(1.24);
         expect(hardNumberParse.value.height.number).toBeCloseTo(2.45);
     });
 
     it("should parse negative sizes", function() {
         const parse = getParsed("\\rule{-1em}{- 0.2em}")[0];
 
         expect(parse.value.width.number).toBeCloseTo(-1);
         expect(parse.value.height.number).toBeCloseTo(-0.2);
     });
 });
 
 describe("A kern parser", function() {
     const emKern = "\\kern{1em}";
     const exKern = "\\kern{1ex}";
     const muKern = "\\kern{1mu}";
     const badUnitRule = "\\kern{1px}";
     const noNumberRule = "\\kern{em}";
 
     it("should list the correct units", function() {
         const emParse = getParsed(emKern)[0];
         const exParse = getParsed(exKern)[0];
         const muParse = getParsed(muKern)[0];
 
         expect(emParse.value.dimension.unit).toEqual("em");
         expect(exParse.value.dimension.unit).toEqual("ex");
         expect(muParse.value.dimension.unit).toEqual("mu");
     });
 
     it("should not parse invalid units", function() {
         expect(badUnitRule).toNotParse();
         expect(noNumberRule).toNotParse();
     });
 
     it("should parse negative sizes", function() {
         const parse = getParsed("\\kern{-1em}")[0];
         expect(parse.value.dimension.number).toBeCloseTo(-1);
     });
 
     it("should parse positive sizes", function() {
         const parse = getParsed("\\kern{+1em}")[0];
         expect(parse.value.dimension.number).toBeCloseTo(1);
     });
 });
 
 describe("A non-braced kern parser", function() {
     const emKern = "\\kern1em";
     const exKern = "\\kern 1 ex";
     const muKern = "\\kern 1mu";
     const badUnitRule = "\\kern1px";
     const noNumberRule = "\\kern em";
 
     it("should list the correct units", function() {
         const emParse = getParsed(emKern)[0];
         const exParse = getParsed(exKern)[0];
         const muParse = getParsed(muKern)[0];
 
         expect(emParse.value.dimension.unit).toEqual("em");
         expect(exParse.value.dimension.unit).toEqual("ex");
         expect(muParse.value.dimension.unit).toEqual("mu");
     });
 
     it("should not parse invalid units", function() {
         expect(badUnitRule).toNotParse();
         expect(noNumberRule).toNotParse();
     });
 
     it("should parse negative sizes", function() {
         const parse = getParsed("\\kern-1em")[0];
         expect(parse.value.dimension.number).toBeCloseTo(-1);
     });
 
     it("should parse positive sizes", function() {
         const parse = getParsed("\\kern+1em")[0];
         expect(parse.value.dimension.number).toBeCloseTo(1);
     });
 });
 
 describe("A left/right parser", function() {
     const normalLeftRight = "\\left( \\dfrac{x}{y} \\right)";
     const emptyRight = "\\left( \\dfrac{x}{y} \\right.";
 
     it("should not fail", function() {
         expect(normalLeftRight).toParse();
     });
 
     it("should produce a leftright", function() {
         const parse = getParsed(normalLeftRight)[0];
 
         expect(parse.type).toEqual("leftright");
         expect(parse.value.left).toEqual("(");
         expect(parse.value.right).toEqual(")");
     });
 
     it("should error when it is mismatched", function() {
         const unmatchedLeft = "\\left( \\dfrac{x}{y}";
         const unmatchedRight = "\\dfrac{x}{y} \\right)";
 
         expect(unmatchedLeft).toNotParse();
 
         expect(unmatchedRight).toNotParse();
     });
 
     it("should error when braces are mismatched", function() {
         const unmatched = "{ \\left( \\dfrac{x}{y} } \\right)";
         expect(unmatched).toNotParse();
     });
 
     it("should error when non-delimiters are provided", function() {
         const nonDelimiter = "\\left$ \\dfrac{x}{y} \\right)";
         expect(nonDelimiter).toNotParse();
     });
 
     it("should parse the empty '.' delimiter", function() {
         expect(emptyRight).toParse();
     });
 
     it("should parse the '.' delimiter with normal sizes", function() {
         const normalEmpty = "\\Bigl .";
         expect(normalEmpty).toParse();
     });
 
     it("should handle \\middle", function() {
         const normalMiddle = "\\left( \\dfrac{x}{y} \\middle| \\dfrac{y}{z} \\right)";
         expect(normalMiddle).toParse();
     });
 
     it("should handle multiple \\middles", function() {
         const multiMiddle = "\\left( \\dfrac{x}{y} \\middle| \\dfrac{y}{z} \\middle/ \\dfrac{z}{q} \\right)";
         expect(multiMiddle).toParse();
     });
 
     it("should handle nested \\middles", function() {
         const nestedMiddle = "\\left( a^2 \\middle| \\left( b \\middle/ c \\right) \\right)";
         expect(nestedMiddle).toParse();
     });
 
     it("should error when \\middle is not in \\left...\\right", function() {
         const unmatchedMiddle = "(\\middle|\\dfrac{x}{y})";
         expect(unmatchedMiddle).toNotParse();
     });
 });
 
 describe("A begin/end parser", function() {
 
     it("should parse a simple environment", function() {
         expect("\\begin{matrix}a&b\\\\c&d\\end{matrix}").toParse();
     });
 
     it("should parse an environment with argument", function() {
         expect("\\begin{array}{cc}a&b\\\\c&d\\end{array}").toParse();
     });
 
     it("should error when name is mismatched", function() {
         expect("\\begin{matrix}a&b\\\\c&d\\end{pmatrix}").toNotParse();
     });
 
     it("should error when commands are mismatched", function() {
         expect("\\begin{matrix}a&b\\\\c&d\\right{pmatrix}").toNotParse();
     });
 
     it("should error when end is missing", function() {
         expect("\\begin{matrix}a&b\\\\c&d").toNotParse();
     });
 
     it("should error when braces are mismatched", function() {
         expect("{\\begin{matrix}a&b\\\\c&d}\\end{matrix}").toNotParse();
     });
 
     it("should cooperate with infix notation", function() {
         expect("\\begin{matrix}0&1\\over2&3\\\\4&5&6\\end{matrix}").toParse();
     });
 
     it("should nest", function() {
         const m1 = "\\begin{pmatrix}1&2\\\\3&4\\end{pmatrix}";
         const m2 = "\\begin{array}{rl}" + m1 + "&0\\\\0&" + m1 + "\\end{array}";
         expect(m2).toParse();
     });
 
     it("should allow \\cr as a line terminator", function() {
         expect("\\begin{matrix}a&b\\cr c&d\\end{matrix}").toParse();
     });
 });
 
 describe("A sqrt parser", function() {
     const sqrt = "\\sqrt{x}";
     const missingGroup = "\\sqrt";
 
     it("should parse square roots", function() {
         expect(sqrt).toParse();
     });
 
     it("should error when there is no group", function() {
         expect(missingGroup).toNotParse();
     });
 
     it("should produce sqrts", function() {
         const parse = getParsed(sqrt)[0];
 
         expect(parse.type).toEqual("sqrt");
     });
 });
 
 describe("A TeX-compliant parser", function() {
     it("should work", function() {
         expect("\\frac 2 3").toParse();
     });
 
     it("should fail if there are not enough arguments", function() {
         const missingGroups = [
             "\\frac{x}",
             "\\color{#fff}",
             "\\rule{1em}",
             "\\llap",
             "\\bigl",
             "\\text",
         ];
 
         for (let i = 0; i < missingGroups.length; i++) {
             expect(missingGroups[i]).toNotParse();
         }
     });
 
     it("should fail when there are missing sup/subscripts", function() {
         expect("x^").toNotParse();
         expect("x_").toNotParse();
     });
 
     it("should fail when arguments require arguments", function() {
         const badArguments = [
             "\\frac \\frac x y z",
             "\\frac x \\frac y z",
             "\\frac \\sqrt x y",
             "\\frac x \\sqrt y",
             "\\frac \\llap x y",
             "\\frac x \\llap y",
             // This actually doesn't work in real TeX, but it is suprisingly
             // hard to get this to correctly work. So, we take hit of very small
             // amounts of non-compatiblity in order for the rest of the tests to
             // work
             // "\\llap \\frac x y",
             "\\llap \\llap x",
             "\\sqrt \\llap x",
         ];
 
         for (let i = 0; i < badArguments.length; i++) {
             expect(badArguments[i]).toNotParse();
         }
     });
 
     it("should work when the arguments have braces", function() {
         const goodArguments = [
             "\\frac {\\frac x y} z",
             "\\frac x {\\frac y z}",
             "\\frac {\\sqrt x} y",
             "\\frac x {\\sqrt y}",
             "\\frac {\\llap x} y",
             "\\frac x {\\llap y}",
             "\\llap {\\frac x y}",
             "\\llap {\\llap x}",
             "\\sqrt {\\llap x}",
         ];
 
         for (let i = 0; i < goodArguments.length; i++) {
             expect(goodArguments[i]).toParse();
         }
     });
 
     it("should fail when sup/subscripts require arguments", function() {
         const badSupSubscripts = [
             "x^\\sqrt x",
             "x^\\llap x",
             "x_\\sqrt x",
             "x_\\llap x",
         ];
 
         for (let i = 0; i < badSupSubscripts.length; i++) {
             expect(badSupSubscripts[i]).toNotParse();
         }
     });
 
     it("should work when sup/subscripts arguments have braces", function() {
         const goodSupSubscripts = [
             "x^{\\sqrt x}",
             "x^{\\llap x}",
             "x_{\\sqrt x}",
             "x_{\\llap x}",
         ];
 
         for (let i = 0; i < goodSupSubscripts.length; i++) {
             expect(goodSupSubscripts[i]).toParse();
         }
     });
 
     it("should parse multiple primes correctly", function() {
         expect("x''''").toParse();
         expect("x_2''").toParse();
         expect("x''_2").toParse();
     });
 
     it("should fail when sup/subscripts are interspersed with arguments", function() {
         expect("\\sqrt^23").toNotParse();
         expect("\\frac^234").toNotParse();
         expect("\\frac2^34").toNotParse();
     });
 
     it("should succeed when sup/subscripts come after whole functions", function() {
         expect("\\sqrt2^3").toParse();
         expect("\\frac23^4").toParse();
     });
 
     it("should succeed with a sqrt around a text/frac", function() {
         expect("\\sqrt \\frac x y").toParse();
         expect("\\sqrt \\text x").toParse();
         expect("x^\\frac x y").toParse();
         expect("x_\\text x").toParse();
     });
 
     it("should fail when arguments are \\left", function() {
         const badLeftArguments = [
             "\\frac \\left( x \\right) y",
             "\\frac x \\left( y \\right)",
             "\\llap \\left( x \\right)",
             "\\sqrt \\left( x \\right)",
             "x^\\left( x \\right)",
         ];
 
         for (let i = 0; i < badLeftArguments.length; i++) {
             expect(badLeftArguments[i]).toNotParse();
         }
     });
 
     it("should succeed when there are braces around the \\left/\\right", function() {
         const goodLeftArguments = [
             "\\frac {\\left( x \\right)} y",
             "\\frac x {\\left( y \\right)}",
             "\\llap {\\left( x \\right)}",
             "\\sqrt {\\left( x \\right)}",
             "x^{\\left( x \\right)}",
         ];
 
         for (let i = 0; i < goodLeftArguments.length; i++) {
             expect(goodLeftArguments[i]).toParse();
         }
     });
 });
 
 describe("A style change parser", function() {
     it("should not fail", function() {
         expect("\\displaystyle x").toParse();
         expect("\\textstyle x").toParse();
         expect("\\scriptstyle x").toParse();
         expect("\\scriptscriptstyle x").toParse();
     });
 
     it("should produce the correct style", function() {
         const displayParse = getParsed("\\displaystyle x")[0];
         expect(displayParse.value.style).toEqual("display");
 
         const scriptscriptParse = getParsed("\\scriptscriptstyle x")[0];
         expect(scriptscriptParse.value.style).toEqual("scriptscript");
     });
 
     it("should only change the style within its group", function() {
         const text = "a b { c d \\displaystyle e f } g h";
         const parse = getParsed(text);
 
         const displayNode = parse[2].value[2];
 
         expect(displayNode.type).toEqual("styling");
 
         const displayBody = displayNode.value.value;
 
         expect(displayBody.length).toEqual(2);
         expect(displayBody[0].value).toEqual("e");
     });
 });
 
 describe("A font parser", function() {
     it("should parse \\mathrm, \\mathbb, and \\mathit", function() {
         expect("\\mathrm x").toParse();
         expect("\\mathbb x").toParse();
         expect("\\mathit x").toParse();
         expect("\\mathrm {x + 1}").toParse();
         expect("\\mathbb {x + 1}").toParse();
         expect("\\mathit {x + 1}").toParse();
     });
 
     it("should parse \\mathcal and \\mathfrak", function() {
         expect("\\mathcal{ABC123}").toParse();
         expect("\\mathfrak{abcABC123}").toParse();
     });
 
     it("should produce the correct fonts", function() {
         const mathbbParse = getParsed("\\mathbb x")[0];
         expect(mathbbParse.value.font).toEqual("mathbb");
         expect(mathbbParse.value.type).toEqual("font");
 
         const mathrmParse = getParsed("\\mathrm x")[0];
         expect(mathrmParse.value.font).toEqual("mathrm");
         expect(mathrmParse.value.type).toEqual("font");
 
         const mathitParse = getParsed("\\mathit x")[0];
         expect(mathitParse.value.font).toEqual("mathit");
         expect(mathitParse.value.type).toEqual("font");
 
         const mathcalParse = getParsed("\\mathcal C")[0];
         expect(mathcalParse.value.font).toEqual("mathcal");
         expect(mathcalParse.value.type).toEqual("font");
 
         const mathfrakParse = getParsed("\\mathfrak C")[0];
         expect(mathfrakParse.value.font).toEqual("mathfrak");
         expect(mathfrakParse.value.type).toEqual("font");
     });
 
     it("should parse nested font commands", function() {
         const nestedParse = getParsed("\\mathbb{R \\neq \\mathrm{R}}")[0];
         expect(nestedParse.value.font).toEqual("mathbb");
         expect(nestedParse.value.type).toEqual("font");
 
         expect(nestedParse.value.body.value.length).toEqual(3);
         const bbBody = nestedParse.value.body.value;
         expect(bbBody[0].type).toEqual("mathord");
         expect(bbBody[1].type).toEqual("rel");
         expect(bbBody[2].type).toEqual("font");
         expect(bbBody[2].value.font).toEqual("mathrm");
         expect(bbBody[2].value.type).toEqual("font");
     });
 
     it("should work with \\color", function() {
         const colorMathbbParse = getParsed("\\color{blue}{\\mathbb R}")[0];
         expect(colorMathbbParse.value.type).toEqual("color");
         expect(colorMathbbParse.value.color).toEqual("blue");
         const body = colorMathbbParse.value.value;
         expect(body.length).toEqual(1);
         expect(body[0].value.type).toEqual("font");
         expect(body[0].value.font).toEqual("mathbb");
     });
 
     it("should not parse a series of font commands", function() {
         expect("\\mathbb \\mathrm R").toNotParse();
     });
 
     it("should nest fonts correctly", function() {
         const bf = getParsed("\\mathbf{a\\mathrm{b}c}")[0];
         expect(bf.value.type).toEqual("font");
         expect(bf.value.font).toEqual("mathbf");
         expect(bf.value.body.value.length).toEqual(3);
         expect(bf.value.body.value[0].value).toEqual("a");
         expect(bf.value.body.value[1].value.type).toEqual("font");
         expect(bf.value.body.value[1].value.font).toEqual("mathrm");
         expect(bf.value.body.value[2].value).toEqual("c");
     });
 
     it("should have the correct greediness", function() {
         expect("e^\\mathbf{x}").toParse();
     });
 });
 
 describe("An HTML font tree-builder", function() {
     it("should render \\mathbb{R} with the correct font", function() {
         const markup = katex.renderToString("\\mathbb{R}");
         expect(markup).toContain("<span class=\"mord mathbb\">R</span>");
     });
 
     it("should render \\mathrm{R} with the correct font", function() {
         const markup = katex.renderToString("\\mathrm{R}");
         expect(markup).toContain("<span class=\"mord mathrm\">R</span>");
     });
 
     it("should render \\mathcal{R} with the correct font", function() {
         const markup = katex.renderToString("\\mathcal{R}");
         expect(markup).toContain("<span class=\"mord mathcal\">R</span>");
     });
 
     it("should render \\mathfrak{R} with the correct font", function() {
         const markup = katex.renderToString("\\mathfrak{R}");
         expect(markup).toContain("<span class=\"mord mathfrak\">R</span>");
     });
 
     it("should render \\text{R} with the correct font", function() {
         const markup = katex.renderToString("\\text{R}");
         expect(markup).toContain("<span class=\"mord mathrm\">R</span>");
     });
 
     it("should render \\textit{R} with the correct font", function() {
         const markup = katex.renderToString("\\textit{R}");
         expect(markup).toContain("<span class=\"mord textit\">R</span>");
     });
 
     it("should render \\text{\\textit{R}} with the correct font", function() {
         const markup = katex.renderToString("\\text{\\textit{R}}");
         expect(markup).toContain("<span class=\"mord textit\">R</span>");
     });
 
     it("should render \\text{R\\textit{S}T} with the correct fonts", function() {
         const markup = katex.renderToString("\\text{R\\textit{S}T}");
         expect(markup).toContain("<span class=\"mord mathrm\">R</span>");
         expect(markup).toContain("<span class=\"mord textit\">S</span>");
         expect(markup).toContain("<span class=\"mord mathrm\">T</span>");
     });
 
     it("should render \\textbf{R} with the correct font", function() {
         const markup = katex.renderToString("\\textbf{R}");
         expect(markup).toContain("<span class=\"mord mathbf\">R</span>");
     });
 
     it("should render \\textsf{R} with the correct font", function() {
         const markup = katex.renderToString("\\textsf{R}");
         expect(markup).toContain("<span class=\"mord mathsf\">R</span>");
     });
 
     it("should render \\texttt{R} with the correct font", function() {
         const markup = katex.renderToString("\\texttt{R}");
         expect(markup).toContain("<span class=\"mord mathtt\">R</span>");
     });
 
     it("should render a combination of font and color changes", function() {
         let markup = katex.renderToString("\\color{blue}{\\mathbb R}");
         let span = "<span class=\"mord mathbb\" style=\"color:blue;\">R</span>";
         expect(markup).toContain(span);
 
         markup = katex.renderToString("\\mathbb{\\color{blue}{R}}");
         span = "<span class=\"mord mathbb\" style=\"color:blue;\">R</span>";
         expect(markup).toContain(span);
     });
 
     it("should throw TypeError when the expression is of the wrong type", function() {
         expect(function() {
             katex.renderToString({badInputType: "yes"});
         }).toThrowError(TypeError);
         expect(function() {
             katex.renderToString([1, 2]);
         }).toThrowError(TypeError);
         expect(function() {
             katex.renderToString(undefined);
         }).toThrowError(TypeError);
         expect(function() {
             katex.renderToString(null);
         }).toThrowError(TypeError);
         expect(function() {
             katex.renderToString(1.234);
         }).toThrowError(TypeError);
     });
 
     it("should not throw TypeError when the expression is a supported type", function() {
         expect(function() {
             katex.renderToString("\\sqrt{123}");
         }).not.toThrowError(TypeError);
         expect(function() {
             katex.renderToString(new String("\\sqrt{123}"));
         }).not.toThrowError(TypeError);
     });
 });
 
 
 describe("A MathML font tree-builder", function() {
     const contents = "Ax2k\\omega\\Omega\\imath+";
 
     it("should render " + contents + " with the correct mathvariants", function() {
         const tree = getParsed(contents);
         const markup = buildMathML(tree, contents, defaultOptions).toMarkup();
         expect(markup).toContain("<mi>A</mi>");
         expect(markup).toContain("<mi>x</mi>");
         expect(markup).toContain("<mn>2</mn>");
         expect(markup).toContain("<mi>\u03c9</mi>");   // \omega
         expect(markup).toContain("<mi mathvariant=\"normal\">\u03A9</mi>");   // \Omega
         expect(markup).toContain("<mi>\u0131</mi>");   // \imath
         expect(markup).toContain("<mo>+</mo>");
     });
 
     it("should render \\mathbb{" + contents + "} with the correct mathvariants", function() {
         const tex = "\\mathbb{" + contents + "}";
         const tree = getParsed(tex);
         const markup = buildMathML(tree, tex, defaultOptions).toMarkup();
         expect(markup).toContain("<mi mathvariant=\"double-struck\">A</mi>");
         expect(markup).toContain("<mi>x</mi>");
         expect(markup).toContain("<mn mathvariant=\"normal\">2</mn>");
         expect(markup).toContain("<mi>\u03c9</mi>");                        // \omega
         expect(markup).toContain("<mi mathvariant=\"normal\">\u03A9</mi>"); // \Omega
         expect(markup).toContain("<mi>\u0131</mi>");                        // \imath
         expect(markup).toContain("<mo>+</mo>");
     });
 
     it("should render \\mathrm{" + contents + "} with the correct mathvariants", function() {
         const tex = "\\mathrm{" + contents + "}";
         const tree = getParsed(tex);
         const markup = buildMathML(tree, tex, defaultOptions).toMarkup();
         expect(markup).toContain("<mi mathvariant=\"normal\">A</mi>");
         expect(markup).toContain("<mi mathvariant=\"normal\">x</mi>");
         expect(markup).toContain("<mn mathvariant=\"normal\">2</mn>");
         expect(markup).toContain("<mi>\u03c9</mi>");   // \omega
         expect(markup).toContain("<mi mathvariant=\"normal\">\u03A9</mi>");   // \Omega
         expect(markup).toContain("<mi>\u0131</mi>");   // \imath
         expect(markup).toContain("<mo>+</mo>");
     });
 
     it("should render \\mathit{" + contents + "} with the correct mathvariants", function() {
         const tex = "\\mathit{" + contents + "}";
         const tree = getParsed(tex);
         const markup = buildMathML(tree, tex, defaultOptions).toMarkup();
         expect(markup).toContain("<mi mathvariant=\"italic\">A</mi>");
         expect(markup).toContain("<mi mathvariant=\"italic\">x</mi>");
         expect(markup).toContain("<mn mathvariant=\"italic\">2</mn>");
         expect(markup).toContain("<mi mathvariant=\"italic\">\u03c9</mi>");   // \omega
         expect(markup).toContain("<mi mathvariant=\"italic\">\u03A9</mi>");   // \Omega
         expect(markup).toContain("<mi mathvariant=\"italic\">\u0131</mi>");   // \imath
         expect(markup).toContain("<mo>+</mo>");
     });
 
     it("should render \\mathbf{" + contents + "} with the correct mathvariants", function() {
         const tex = "\\mathbf{" + contents + "}";
         const tree = getParsed(tex);
         const markup = buildMathML(tree, tex, defaultOptions).toMarkup();
         expect(markup).toContain("<mi mathvariant=\"bold\">A</mi>");
         expect(markup).toContain("<mi mathvariant=\"bold\">x</mi>");
         expect(markup).toContain("<mn mathvariant=\"bold\">2</mn>");
         expect(markup).toContain("<mi>\u03c9</mi>");                        // \omega
         expect(markup).toContain("<mi mathvariant=\"bold\">\u03A9</mi>");   // \Omega
         expect(markup).toContain("<mi>\u0131</mi>");                        // \imath
         expect(markup).toContain("<mo>+</mo>");
     });
 
     it("should render \\mathcal{" + contents + "} with the correct mathvariants", function() {
         const tex = "\\mathcal{" + contents + "}";
         const tree = getParsed(tex);
         const markup = buildMathML(tree, tex, defaultOptions).toMarkup();
         expect(markup).toContain("<mi mathvariant=\"script\">A</mi>");
         expect(markup).toContain("<mi>x</mi>");                             // script is caps only
         expect(markup).toContain("<mn mathvariant=\"script\">2</mn>");
         // MathJax marks everything below as "script" except \omega
         // We don't have these glyphs in "caligraphic" and neither does MathJax
         expect(markup).toContain("<mi>\u03c9</mi>");                        // \omega
         expect(markup).toContain("<mi mathvariant=\"normal\">\u03A9</mi>"); // \Omega
         expect(markup).toContain("<mi>\u0131</mi>");                        // \imath
         expect(markup).toContain("<mo>+</mo>");
     });
 
     it("should render \\mathfrak{" + contents + "} with the correct mathvariants", function() {
         const tex = "\\mathfrak{" + contents + "}";
         const tree = getParsed(tex);
         const markup = buildMathML(tree, tex, defaultOptions).toMarkup();
         expect(markup).toContain("<mi mathvariant=\"fraktur\">A</mi>");
         expect(markup).toContain("<mi mathvariant=\"fraktur\">x</mi>");
         expect(markup).toContain("<mn mathvariant=\"fraktur\">2</mn>");
         // MathJax marks everything below as "fraktur" except \omega
         // We don't have these glyphs in "fraktur" and neither does MathJax
         expect(markup).toContain("<mi>\u03c9</mi>");                        // \omega
         expect(markup).toContain("<mi mathvariant=\"normal\">\u03A9</mi>"); // \Omega
         expect(markup).toContain("<mi>\u0131</mi>");                        // \imath
         expect(markup).toContain("<mo>+</mo>");
     });
 
     it("should render \\mathscr{" + contents + "} with the correct mathvariants", function() {
         const tex = "\\mathscr{" + contents + "}";
         const tree = getParsed(tex);
         const markup = buildMathML(tree, tex, defaultOptions).toMarkup();
         expect(markup).toContain("<mi mathvariant=\"script\">A</mi>");
         // MathJax marks everything below as "script" except \omega
         // We don't have these glyphs in "script" and neither does MathJax
         expect(markup).toContain("<mi>x</mi>");
         expect(markup).toContain("<mn mathvariant=\"normal\">2</mn>");
         expect(markup).toContain("<mi>\u03c9</mi>");                        // \omega
         expect(markup).toContain("<mi mathvariant=\"normal\">\u03A9</mi>"); // \Omega
         expect(markup).toContain("<mi>\u0131</mi>");                        // \imath
         expect(markup).toContain("<mo>+</mo>");
     });
 
     it("should render \\mathsf{" + contents + "} with the correct mathvariants", function() {
         const tex = "\\mathsf{" + contents + "}";
         const tree = getParsed(tex);
         const markup = buildMathML(tree, tex, defaultOptions).toMarkup();
         expect(markup).toContain("<mi mathvariant=\"sans-serif\">A</mi>");
         expect(markup).toContain("<mi mathvariant=\"sans-serif\">x</mi>");
         expect(markup).toContain("<mn mathvariant=\"sans-serif\">2</mn>");
         expect(markup).toContain("<mi>\u03c9</mi>");                            // \omega
         expect(markup).toContain("<mi mathvariant=\"sans-serif\">\u03A9</mi>"); // \Omega
         expect(markup).toContain("<mi>\u0131</mi>");                            // \imath
         expect(markup).toContain("<mo>+</mo>");
     });
 
     it("should render a combination of font and color changes", function() {
         let tex = "\\color{blue}{\\mathbb R}";
         let tree = getParsed(tex);
         let markup = buildMathML(tree, tex, defaultOptions).toMarkup();
         let node = "<mstyle mathcolor=\"blue\">" +
             "<mi mathvariant=\"double-struck\">R</mi>" +
             "</mstyle>";
         expect(markup).toContain(node);
 
         // reverse the order of the commands
         tex = "\\mathbb{\\color{blue}{R}}";
         tree = getParsed(tex);
         markup = buildMathML(tree, tex, defaultOptions).toMarkup();
         node = "<mstyle mathcolor=\"blue\">" +
             "<mi mathvariant=\"double-struck\">R</mi>" +
             "</mstyle>";
         expect(markup).toContain(node);
     });
 });
 
 describe("A bin builder", function() {
     it("should create mbins normally", function() {
         const built = getBuilt("x + y");
 
         expect(built[1].classes).toContain("mbin");
     });
 
     it("should create ords when at the beginning of lists", function() {
         const built = getBuilt("+ x");
 
         expect(built[0].classes).toContain("mord");
         expect(built[0].classes).not.toContain("mbin");
     });
 
     it("should create ords after some other objects", function() {
         expect(getBuilt("x + + 2")[2].classes).toContain("mord");
         expect(getBuilt("( + 2")[1].classes).toContain("mord");
         expect(getBuilt("= + 2")[1].classes).toContain("mord");
         expect(getBuilt("\\sin + 2")[1].classes).toContain("mord");
         expect(getBuilt(", + 2")[1].classes).toContain("mord");
     });
 
     it("should correctly interact with color objects", function() {
         expect(getBuilt("\\blue{x}+y")[1].classes).toContain("mbin");
         expect(getBuilt("\\blue{x+}+y")[1].classes).toContain("mbin");
         expect(getBuilt("\\blue{x+}+y")[2].classes).toContain("mord");
     });
 });
 
 describe("A markup generator", function() {
     it("marks trees up", function() {
         // Just a few quick sanity checks here...
         const markup = katex.renderToString("\\sigma^2");
         expect(markup.indexOf("<span")).toBe(0);
         expect(markup).toContain("\u03c3");  // sigma
         expect(markup).toContain("margin-right");
         expect(markup).not.toContain("marginRight");
     });
 
     it("generates both MathML and HTML", function() {
         const markup = katex.renderToString("a");
 
         expect(markup).toContain("<span");
         expect(markup).toContain("<math");
     });
 });
 
 describe("A parse tree generator", function() {
     it("generates a tree", function() {
         const tree = stripPositions(katex.__parse("\\sigma^2"));
         expect(JSON.stringify(tree)).toEqual(JSON.stringify([
             {
                 "type": "supsub",
                 "value": {
                     "base": {
                         "type": "mathord",
                         "value": "\\sigma",
                         "mode": "math",
                     },
                     "sup": {
                         "type": "textord",
                         "value": "2",
                         "mode": "math",
                     },
                     "sub": undefined,
                 },
                 "mode": "math",
             },
         ]));
     });
 });
 
 describe("An accent parser", function() {
     it("should not fail", function() {
         expect("\\vec{x}").toParse();
         expect("\\vec{x^2}").toParse();
         expect("\\vec{x}^2").toParse();
         expect("\\vec x").toParse();
     });
 
     it("should produce accents", function() {
         const parse = getParsed("\\vec x")[0];
 
         expect(parse.type).toEqual("accent");
     });
 
     it("should be grouped more tightly than supsubs", function() {
         const parse = getParsed("\\vec x^2")[0];
 
         expect(parse.type).toEqual("supsub");
     });
 
     it("should not parse expanding accents", function() {
         expect("\\widehat{x}").toNotParse();
     });
 });
 
 describe("An accent builder", function() {
     it("should not fail", function() {
         expect("\\vec{x}").toBuild();
         expect("\\vec{x}^2").toBuild();
         expect("\\vec{x}_2").toBuild();
         expect("\\vec{x}_2^2").toBuild();
     });
 
     it("should produce mords", function() {
         expect(getBuilt("\\vec x")[0].classes).toContain("mord");
         expect(getBuilt("\\vec +")[0].classes).toContain("mord");
         expect(getBuilt("\\vec +")[0].classes).not.toContain("mbin");
         expect(getBuilt("\\vec )^2")[0].classes).toContain("mord");
         expect(getBuilt("\\vec )^2")[0].classes).not.toContain("mclose");
     });
 });
 
 describe("A phantom parser", function() {
     it("should not fail", function() {
         expect("\\phantom{x}").toParse();
         expect("\\phantom{x^2}").toParse();
         expect("\\phantom{x}^2").toParse();
         expect("\\phantom x").toParse();
     });
 
     it("should build a phantom node", function() {
         const parse = getParsed("\\phantom{x}")[0];
 
         expect(parse.type).toEqual("phantom");
         expect(parse.value.value).toBeDefined();
     });
 });
 
 describe("A phantom builder", function() {
     it("should not fail", function() {
         expect("\\phantom{x}").toBuild();
         expect("\\phantom{x^2}").toBuild();
         expect("\\phantom{x}^2").toBuild();
         expect("\\phantom x").toBuild();
     });
 
     it("should make the children transparent", function() {
         const children = getBuilt("\\phantom{x+1}");
         expect(children[0].style.color).toBe("transparent");
         expect(children[1].style.color).toBe("transparent");
         expect(children[2].style.color).toBe("transparent");
     });
 
     it("should make all descendants transparent", function() {
         const children = getBuilt("\\phantom{x+\\blue{1}}");
         expect(children[0].style.color).toBe("transparent");
         expect(children[1].style.color).toBe("transparent");
         expect(children[2].style.color).toBe("transparent");
     });
 });
 
 describe("A parser error", function() {
     it("should report the position of an error", function() {
         try {
             parseTree("\\sqrt}", defaultSettings);
         } catch (e) {
             expect(e.position).toEqual(5);
         }
     });
 });
 
 describe("An optional argument parser", function() {
     it("should not fail", function() {
         // Note this doesn't actually make an optional argument, but still
         // should work
         expect("\\frac[1]{2}{3}").toParse();
 
         expect("\\rule[0.2em]{1em}{1em}").toParse();
     });
 
     it("should work with sqrts with optional arguments", function() {
         expect("\\sqrt[3]{2}").toParse();
     });
 
     it("should work when the optional argument is missing", function() {
         expect("\\sqrt{2}").toParse();
         expect("\\rule{1em}{2em}").toParse();
     });
 
     it("should fail when the optional argument is malformed", function() {
         expect("\\rule[1]{2em}{3em}").toNotParse();
     });
 
     it("should not work if the optional argument isn't closed", function() {
         expect("\\sqrt[").toNotParse();
     });
 });
 
 describe("An array environment", function() {
 
     it("should accept a single alignment character", function() {
         const parse = getParsed("\\begin{array}r1\\\\20\\end{array}");
         expect(parse[0].type).toBe("array");
         expect(parse[0].value.cols).toEqual([
             { type: "align", align: "r" },
         ]);
     });
 
     it("should accept vertical separators", function() {
         const parse = getParsed("\\begin{array}{|l||c|}\\end{array}");
         expect(parse[0].type).toBe("array");
         expect(parse[0].value.cols).toEqual([
             { type: "separator", separator: "|" },
             { type: "align", align: "l" },
             { type: "separator", separator: "|" },
             { type: "separator", separator: "|" },
             { type: "align", align: "c" },
             { type: "separator", separator: "|" },
         ]);
     });
 
 });
 
 describe("A cases environment", function() {
 
     it("should parse its input", function() {
         expect("f(a,b)=\\begin{cases}a+1&\\text{if }b\\text{ is odd}\\\\" +
                "a&\\text{if }b=0\\\\a-1&\\text{otherwise}\\end{cases}")
             .toParse();
     });
 
 });
 
 describe("An aligned environment", function() {
 
     it("should parse its input", function() {
         expect("\\begin{aligned}a&=b&c&=d\\\\e&=f\\end{aligned}")
             .toParse();
     });
 
 });
 
 const getMathML = function(expr, settings) {
     const usedSettings = settings ? settings : defaultSettings;
 
     expect(expr).toParse(usedSettings);
 
     const built = buildMathML(parseTree(expr, usedSettings), expr, usedSettings);
 
     // Strip off the surrounding <span>
     return built.children[0];
 };
 
 describe("A MathML builder", function() {
     it("should generate math nodes", function() {
         const node = getMathML("x^2");
 
         expect(node.type).toEqual("math");
     });
 
     it("should generate appropriate MathML types", function() {
         const identifier = getMathML("x").children[0].children[0];
         expect(identifier.children[0].type).toEqual("mi");
 
         const number = getMathML("1").children[0].children[0];
         expect(number.children[0].type).toEqual("mn");
 
         const operator = getMathML("+").children[0].children[0];
         expect(operator.children[0].type).toEqual("mo");
 
         const space = getMathML("\\;").children[0].children[0];
         expect(space.children[0].type).toEqual("mspace");
 
         const text = getMathML("\\text{a}").children[0].children[0];
         expect(text.children[0].type).toEqual("mtext");
 
         const textop = getMathML("\\sin").children[0].children[0];
         expect(textop.children[0].type).toEqual("mi");
     });
 
     it("should generate a <mphantom> node for \\phantom", function() {
         const phantom = getMathML("\\phantom{x}").children[0].children[0];
         expect(phantom.children[0].type).toEqual("mphantom");
     });
 });
 
 describe("A parser that does not throw on unsupported commands", function() {
     // The parser breaks on unsupported commands unless it is explicitly
     // told not to
     const errorColor = "#933";
     const noThrowSettings = new Settings({
         throwOnError: false,
         errorColor: errorColor,
     });
 
     it("should still parse on unrecognized control sequences", function() {
         expect("\\error").toParse(noThrowSettings);
     });
 
     describe("should allow unrecognized controls sequences anywhere, including", function() {
         it("in superscripts and subscripts", function() {
             expect("2_\\error").toBuild(noThrowSettings);
             expect("3^{\\error}_\\error").toBuild(noThrowSettings);
             expect("\\int\\nolimits^\\error_\\error").toBuild(noThrowSettings);
         });
 
         it("in fractions", function() {
             expect("\\frac{345}{\\error}").toBuild(noThrowSettings);
             expect("\\frac\\error{\\error}").toBuild(noThrowSettings);
         });
 
         it("in square roots", function() {
             expect("\\sqrt\\error").toBuild(noThrowSettings);
             expect("\\sqrt{234\\error}").toBuild(noThrowSettings);
         });
 
         it("in text boxes", function() {
             expect("\\text{\\error}").toBuild(noThrowSettings);
         });
     });
 
     it("should produce color nodes with a color value given by errorColor", function() {
         const parsedInput = getParsed("\\error", noThrowSettings);
         expect(parsedInput[0].type).toBe("color");
         expect(parsedInput[0].value.color).toBe(errorColor);
     });
 });
 
 describe("The symbol table integraty", function() {
     it("should treat certain symbols as synonyms", function() {
         expect(getBuilt("<")).toEqual(getBuilt("\\lt"));
         expect(getBuilt(">")).toEqual(getBuilt("\\gt"));
         expect(getBuilt("\\left<\\frac{1}{x}\\right>"))
             .toEqual(getBuilt("\\left\\lt\\frac{1}{x}\\right\\gt"));
     });
 });
 
 describe("A macro expander", function() {
 
     const compareParseTree = function(actual, expected, macros) {
         const settings = new Settings({macros: macros});
         actual = stripPositions(parseTree(actual, settings));
         expected = stripPositions(parseTree(expected, defaultSettings));
         expect(actual).toEqual(expected);
     };
 
     it("should produce individual tokens", function() {
         compareParseTree("e^\\foo", "e^1 23", {"\\foo": "123"});
     });
 
     it("should allow for multiple expansion", function() {
         compareParseTree("1\\foo2", "1aa2", {
             "\\foo": "\\bar\\bar",
             "\\bar": "a",
         });
     });
 
     it("should expand the \overset macro as expected", function() {
         expect("\\overset?=").toParseLike("\\mathop{=}\\limits^{?}");
         expect("\\overset{x=y}{\sqrt{ab}}")
             .toParseLike("\\mathop{\sqrt{ab}}\\limits^{x=y}");
         expect("\\overset {?} =").toParseLike("\\mathop{=}\\limits^{?}");
     });
 });
 
 describe("A parser taking String objects", function() {
     it("should not fail on an empty String object", function() {
         expect(new String("")).toParse();
     });
 
     it("should parse the same as a regular string", function() {
         expect(new String("xy")).toParseLike("xy");
         expect(new String("\\div")).toParseLike("\\div");
         expect(new String("\\frac 1 2")).toParseLike("\\frac 1 2");
     });
 });