Switch from nomnom to commander (#1496)

* Switch from nomnom to commander

* Fix #1489
* --macro repeatable option replaced with single --macros option with ";"
  separator (until https://github.com/tj/commander.js/issues/674)
* Add missing --max-expand option
* Replace expired --unicode-text-in-math-mode option with --strict
  (https://github.com/Khan/KaTeX/issues/1483#issuecomment-405108291)
* Add instructions for how to run in the opening comments
* Clean up option doc strings

* Implement @ylemkimon's comments

* Fix try/const bug

* Fix use of --selenium-ip

It was a quirk that --seleniumIP worked.  --help lists --selenium-ip.

* Implement comments, restore --macro repeatable argument

* Cleanup

* Restore 0 default for maxExpand

* Fix more comments from @ylemkimon

* npm run dist -> npm run build

In preparation for #1500

* Fix line length error

cli.js

@@ -1,103 +1,67 @@
 #!/usr/bin/env node
 // Simple CLI for KaTeX.
 // Reads TeX from stdin, outputs HTML to stdout.
+// To run this from the repository, you must first build KaTeX by running
+// `npm install` and `npm run build`.
+
 /* eslint no-console:0 */
 
-const katex = require("./");
+let katex;
+try {
+    katex = require("./");
+} catch (e) {
+    console.error(
+        "KaTeX could not import, likely because dist/katex.js is missing.");
+    console.error("Please run 'npm install' and 'npm run build' before running");
+    console.error("cli.js from the KaTeX repository.");
+    console.error();
+    throw e;
+}
+const {version} = require("./package.json");
 const fs = require("fs");
 
-const options = require("nomnom")
-    .option("displayMode", {
-        full: "display-mode",
-        abbr: "d",
-        flag: true,
-        default: false,
-        help: "If true the math will be rendered in display " +
-              "mode, which will put the math in display style " +
-              "(so \\int and \\sum are large, for example), and " +
-              "will center the math on the page on its own line.",
-    })
-    .option("throwOnError", {
-        full: "no-throw-on-error",
-        abbr: "t",
-        flag: true,
-        default: true,
-        transform: function(t) {
-            return !t;
-        },
-        help: "If true, KaTeX will throw a ParseError when it " +
-              "encounters an unsupported command. If false, KaTeX " +
-              "will render the unsupported command as text in the " +
-              "color given by errorColor.",
-    })
-    .option("errorColor", {
-        full: "error-color",
-        abbr: "c",
-        metavar: "color",
-        default: "#cc0000",
-        transform: function(color) {
-            return "#" + color;
-        },
-        help: "A color string given in the format 'rgb' or 'rrggbb'. " +
-              "This option determines the color which unsupported " +
-              "commands are rendered in.",
-    })
-    .option("colorIsTextColor", {
-        full: "color-is-text-color",
-        abbr: "b",
-        flag: true,
-        default: false,
-        help: "Makes \\color behave like LaTeX's 2-argument \\textcolor, " +
-              "instead of LaTeX's one-argument \\color mode change.",
-    })
-    .option("unicodeTextInMathMode", {
-        full: "unicode-text-in-math-mode",
-        abbr: "u",
-        flag: true,
-        default: false,
-        help: "Add support for unicode text characters in math mode.",
-    })
-    .option("maxSize", {
-        full: "max-size",
-        abbr: "s",
-        metavar: "size",
-        default: 0,
-        help: "If non-zero, all user-specified sizes, e.g. in " +
-              "\\rule{500em}{500em}, will be capped to maxSize ems. " +
-              "Otherwise, elements and spaces can be arbitrarily large",
-    })
-    .option("macros", {
-        full: "macro",
-        abbr: "m",
-        metavar: "macro:expansion",
-        list: true,
-        default: [],
-        help: "A custom macro. Each macro is a property with a name " +
-              "like \\name which maps to a string that " +
-              "describes the expansion of the macro.",
-    })
-    .option("macroFile", {
-        full: "macro-file",
-        abbr: "f",
-        metavar: "path",
-        default: null,
-        help: "Read macro definitions from the given file.",
-    })
-    .option("inputFile", {
-        full: "input",
-        abbr: "i",
-        metavar: "path",
-        default: null,
-        help: "Read LaTeX input from the given file.",
-    })
-    .option("outputFile", {
-        full: "output",
-        abbr: "o",
-        metavar: "path",
-        default: null,
-        help: "Write html output to the given file.",
-    })
-    .parse();
+const options = require("commander")
+    .version(version)
+    .option("-d, --display-mode",
+        "Render math in display mode, which puts the math in display style " +
+        "(so \\int and \\sum are large, for example), and centers the math " +
+        "on the page on its own line.")
+    .option("-t, --no-throw-on-error",
+        "Render errors (in the color given by --error-color) instead of " +
+        "throwing a ParseError exception when encountering an error.")
+    .option("-c, --error-color <color>",
+        "A color string given in the format 'rgb' or 'rrggbb' (no #). " +
+        "This option determines the color of errors rendered by the -t option.",
+        "#cc0000",
+        (color) => "#" + color)
+    .option("-b, --color-is-text-color",
+        "Makes \\color behave like LaTeX's 2-argument \\textcolor, " +
+        "instead of LaTeX's one-argument \\color mode change.")
+    .option("-S, --strict",
+        "Turn on strict / LaTeX faithfulness mode, which throws an error " +
+        "if the input uses features that are not supported by LaTeX")
+    .option("-s, --max-size <n>",
+        "If non-zero, all user-specified sizes, e.g. in " +
+        "\\rule{500em}{500em}, will be capped to maxSize ems. " +
+        "Otherwise, elements and spaces can be arbitrarily large",
+        0, parseInt)
+    .option("-e, --max-expand <n>",
+        "Limit the number of macro expansions to the specified number, to " +
+        "prevent e.g. infinite macro loops.  If set to Infinity, the macro " +
+        "expander will try to fully expand as in LaTeX.",
+        (n) => (n === "Infinity" ? Infinity : parseInt(n)))
+    .option("-m, --macro <def>",
+        "Define custom macro of the form '\\foo:expansion' (use multiple -m " +
+        "arguments for multiple macros).",
+        (def, defs) => {
+            defs.push(def);
+            return defs;
+        }, [])
+    .option("-f, --macro-file <path>",
+        "Read macro definitions, one per line, from the given file.")
+    .option("-i, --input <path>", "Read LaTeX input from the given file.")
+    .option("-o, --output <path>", "Write html output to the given file.")
+    .parse(process.argv);
 
 
 function readMacros() {
@@ -114,7 +78,7 @@ function readMacros() {
 function splitMacros(macroStrings) {
     // Override macros from macro file (if any)
     // with macros from command line (if any)
-    macroStrings = macroStrings.concat(options.macros);
+    macroStrings = macroStrings.concat(options.macro);
 
     const macros = {};
 
@@ -132,8 +96,8 @@ function splitMacros(macroStrings) {
 function readInput() {
     let input = "";
 
-    if (options.inputFile) {
-        fs.readFile(options.inputFile, "utf-8", function(err, data) {
+    if (options.input) {
+        fs.readFile(options.input, "utf-8", function(err, data) {
             if (err) {throw err;}
             input = data.toString();
             writeOutput(input);
@@ -152,8 +116,8 @@ function readInput() {
 function writeOutput(input) {
     const output = katex.renderToString(input, options) + "\n";
 
-    if (options.outputFile) {
-        fs.writeFile(options.outputFile, output, function(err) {
+    if (options.output) {
+        fs.writeFile(options.output, output, function(err) {
             if (err) {
                 return console.log(err);
             }