venning · March 23, 2015 17:20
diff --git a/README b/README
 This is intended to be run in Node.  Provided a path to the lodash source file as a command-line argument.

 There were a few edge case handlers that I removed; they only helped in a few places while severely reducing code clarity.  There's also some weirdness with how it interprets literals that cause them to not match (see _.escapeRegExp), but it's not worth the time to fix.

 Let me know.
diff --git a/check_examples.js b/check_examples.js
 #!/usr/bin/env node

 /*
 *  much of this was taken from:
 *  https://bitbucket.org/ariya/missing-doc/src/master/missing-doc.js
 */

 'use strict';

 var _ = require('lodash'),
    fs = require('fs'),
    esprima = require('esprima'),
    estraverse = require('estraverse'),
    doctrine = require('doctrine'),
    vm = require('vm'),
    indentString = require('indent-string'),
    jsdom = require('jsdom').jsdom; // requires 3.x version to work in node



 /////////////////////////////
 ////  SETUP & CONSTANTS  ////
 /////////////////////////////
 var reResultComment = /^\/\/ => (.*?)(?: \(iteration order is not guaranteed\))?$/;
 var reObjectLiteral = /^\s*{.*}\s*$/;
 // base context for running sandbox VMs; most of this exists to prevent silly errors
 var globalContext = {
    _: _,
    document: jsdom(),
    Uint8Array: Uint8Array,
    require: require,
    console: {
        log: _.identity // this is cheating
    },
    asyncSave: _.noop,
    mage: {
        castSpell: _.noop
    }
 };
 _.times(20, function () {
    var el = globalContext.document.createElement('div');
    globalContext.document.body.appendChild(el);
 });
 _.times(103, _.uniqueId);



 ////////////////////////
 ////  MAIN ROUTINE  ////
 ////////////////////////
 // globals because I'm lazy
 var total = 0,
    successes = 0;

 // lodash source file as command-line argument
 buildAndWalkTree(process.argv[2]);

 console.log('\n' + successes + ' out of ' + total + ' examples succeeeded.')



 ///////////////////
 ////  WORKERS  ////
 ///////////////////
 function buildAndWalkTree (filename) {
    var content, tree;
    try {
        content = fs.readFileSync(filename, 'utf-8');
        tree = esprima.parse(content, { attachComment: true, loc: true });
        // walk the tree
        estraverse.traverse(tree, { enter: workNode });
    } catch (e) {
        console.error(e.toString());
        process.exit(1);
    }
 }

 function workNode (node) {
    if (node.type === 'Identifier') {
        // just a duplicate from something else
        return;
    }
    if (node.leadingComments && node.id && node.id.leadingComments) {
        // this should never happen, but it's worth getting a warning if it does
        console.error(node.id.name + ' has leadingComments in two places in the AST');
        process.exit(1);
    }

    var leadingComments = node.leadingComments || (node.id && node.id.leadingComments);
    var name = node.name || (node.id && node.id.name);

    _.forEach(leadingComments, _.partial(workComment, name));
 }

 function workComment (name, comment) {
    // unwrap: pulls out the leading `*`s; recoverable: allows for badly-formed JSDoc
    var data = doctrine.parse(comment.value, { unwrap: true, recoverable: true });
    // some functions have @name annotations that should take precedence
    name = _.result(_.find(data.tags, { title: 'name' }), 'name') || name;
    // pull out all of the examples
    var examples = _.where(data.tags, { title: 'example' });

    // shouldn't be more than one examples 
    _.forEach(examples, function (example) {
        // do the work
        var errors = testExample(example, name);

        if (errors.length) {
            console.log(name + '\n' + indentString(errors.join('\n'), ' ', 4));
        } else {
            ++successes;
        }
        ++total;
    });
 }

 // executes the example code, comparing with expected output, returning array of errors found
 function testExample (example) {
    var errors = [];
    var lines = example.description.split('\n');

    var sandbox = vm.createContext(globalContext);
    // to prevent issue with ASI and other stupidity, we build up a chunk of code to execute
    var lineBuffer = [];

    for (var i = 0; i < lines.length; ++i) {
        var line = lines[i];
        var match = line.match(reResultComment);
        if (match) { // output comment line
            var expectation = match[1], // what the comment says we should get at this point
                code = lineBuffer.join('\n'),
                result,
                expectedResult;
            lineBuffer = []; // clear it for the next run

            // eval code and check for error
            try {
                var result = evalCode(code, sandbox);
            } catch (e) {
                errors.push('ERROR EXECUTING CODE: ' + e.toString() + '\n' +
                    indentString(code.trimLeft(), ' ', 4));
                continue;
            }

            // eval expectation and check for error
            try {
                var expectedResult = evalCode(expectation);
            } catch (e) {
                errors.push('ERROR PARSING EXPECTED RESULT:\n' +
                    indentString(expectation, ' ', 4));
                continue;
            }

            if (! _.isEqual(result, expectedResult)) {
                errors.push('EXPECTED: ' + expectation + '\n  RESULT: ' + result);
             }
        } else { // regular line of code
            // we can't eval each line independently due to mutli-line expressions
            lineBuffer.push(line);
            // some lines may not execute if there are no expectation comments that follow
        }
    }
    return errors;
 }

 // may throw, which is sort of the point
 function evalCode (code, sandbox) {
    // create a bare context if necessary
    sandbox = sandbox || vm.createContext();
    // fix object literals being mis-interpreted as code blocks
    if (code.match(reObjectLiteral)) {
        code = '(' + code + ')';
    }
    return vm.runInContext(code, sandbox);
 }
diff --git a/package.json b/package.json
 {
  "dependencies": {
    "lodash": "~3.5.0",
    "estraverse": "~3.1.0",
    "esprima": "~2.1.0",
    "doctrine": "~0.6.4",
    "indent-string": "~1.2.1",
    "jsdom": "~3.1.2"
  }
 }
	This is intended to be run in Node. Provided a path to the lodash source file as a command-line argument.

	There were a few edge case handlers that I removed; they only helped in a few places while severely reducing code clarity. There's also some weirdness with how it interprets literals that cause them to not match (see _.escapeRegExp), but it's not worth the time to fix.

	Let me know.
	#!/usr/bin/env node

	/*
	* much of this was taken from:
	* https://bitbucket.org/ariya/missing-doc/src/master/missing-doc.js
	*/

	'use strict';

	var _ = require('lodash'),
	fs = require('fs'),
	esprima = require('esprima'),
	estraverse = require('estraverse'),
	doctrine = require('doctrine'),
	vm = require('vm'),
	indentString = require('indent-string'),
	jsdom = require('jsdom').jsdom; // requires 3.x version to work in node



	/////////////////////////////
	//// SETUP & CONSTANTS ////
	/////////////////////////////
	var reResultComment = /^\/\/ => (.*?)(?: \(iteration order is not guaranteed\))?$/;
	var reObjectLiteral = /^\s{.}\s*$/;
	// base context for running sandbox VMs; most of this exists to prevent silly errors
	var globalContext = {
	_: _,
	document: jsdom(),
	Uint8Array: Uint8Array,
	require: require,
	console: {
	log: _.identity // this is cheating
	},
	asyncSave: _.noop,
	mage: {
	castSpell: _.noop
	}
	};
	_.times(20, function () {
	var el = globalContext.document.createElement('div');
	globalContext.document.body.appendChild(el);
	});
	_.times(103, _.uniqueId);



	////////////////////////
	//// MAIN ROUTINE ////
	////////////////////////
	// globals because I'm lazy
	var total = 0,
	successes = 0;

	// lodash source file as command-line argument
	buildAndWalkTree(process.argv[2]);

	console.log('\n' + successes + ' out of ' + total + ' examples succeeeded.')



	///////////////////
	//// WORKERS ////
	///////////////////
	function buildAndWalkTree (filename) {
	var content, tree;
	try {
	content = fs.readFileSync(filename, 'utf-8');
	tree = esprima.parse(content, { attachComment: true, loc: true });
	// walk the tree
	estraverse.traverse(tree, { enter: workNode });
	} catch (e) {
	console.error(e.toString());
	process.exit(1);
	}
	}

	function workNode (node) {
	if (node.type === 'Identifier') {
	// just a duplicate from something else
	return;
	}
	if (node.leadingComments && node.id && node.id.leadingComments) {
	// this should never happen, but it's worth getting a warning if it does
	console.error(node.id.name + ' has leadingComments in two places in the AST');
	process.exit(1);
	}

	var leadingComments = node.leadingComments \|\| (node.id && node.id.leadingComments);
	var name = node.name \|\| (node.id && node.id.name);

	_.forEach(leadingComments, _.partial(workComment, name));
	}

	function workComment (name, comment) {
	// unwrap: pulls out the leading `*`s; recoverable: allows for badly-formed JSDoc
	var data = doctrine.parse(comment.value, { unwrap: true, recoverable: true });
	// some functions have @name annotations that should take precedence
	name = _.result(_.find(data.tags, { title: 'name' }), 'name') \|\| name;
	// pull out all of the examples
	var examples = _.where(data.tags, { title: 'example' });

	// shouldn't be more than one examples
	_.forEach(examples, function (example) {
	// do the work
	var errors = testExample(example, name);

	if (errors.length) {
	console.log(name + '\n' + indentString(errors.join('\n'), ' ', 4));
	} else {
	++successes;
	}
	++total;
	});
	}

	// executes the example code, comparing with expected output, returning array of errors found
	function testExample (example) {
	var errors = [];
	var lines = example.description.split('\n');

	var sandbox = vm.createContext(globalContext);
	// to prevent issue with ASI and other stupidity, we build up a chunk of code to execute
	var lineBuffer = [];

	for (var i = 0; i < lines.length; ++i) {
	var line = lines[i];
	var match = line.match(reResultComment);
	if (match) { // output comment line
	var expectation = match[1], // what the comment says we should get at this point
	code = lineBuffer.join('\n'),
	result,
	expectedResult;
	lineBuffer = []; // clear it for the next run

	// eval code and check for error
	try {
	var result = evalCode(code, sandbox);
	} catch (e) {
	errors.push('ERROR EXECUTING CODE: ' + e.toString() + '\n' +
	indentString(code.trimLeft(), ' ', 4));
	continue;
	}

	// eval expectation and check for error
	try {
	var expectedResult = evalCode(expectation);
	} catch (e) {
	errors.push('ERROR PARSING EXPECTED RESULT:\n' +
	indentString(expectation, ' ', 4));
	continue;
	}

	if (! _.isEqual(result, expectedResult)) {
	errors.push('EXPECTED: ' + expectation + '\n RESULT: ' + result);
	}
	} else { // regular line of code
	// we can't eval each line independently due to mutli-line expressions
	lineBuffer.push(line);
	// some lines may not execute if there are no expectation comments that follow
	}
	}
	return errors;
	}

	// may throw, which is sort of the point
	function evalCode (code, sandbox) {
	// create a bare context if necessary
	sandbox = sandbox \|\| vm.createContext();
	// fix object literals being mis-interpreted as code blocks
	if (code.match(reObjectLiteral)) {
	code = '(' + code + ')';
	}
	return vm.runInContext(code, sandbox);
	}
	{
	"dependencies": {
	"lodash": "~3.5.0",
	"estraverse": "~3.1.0",
	"esprima": "~2.1.0",
	"doctrine": "~0.6.4",
	"indent-string": "~1.2.1",
	"jsdom": "~3.1.2"
	}
	}