parse.usesCommonJs() method, mainly for volo.

jrburke · jrburke · commit ad1be751ca72 · 2012-01-31T12:04:20.000-08:00
diff --git a/build/jslib/parse.js b/build/jslib/parse.js
@@ -7,7 +7,7 @@
 /*jslint plusplus: false, strict: false */
 /*global define: false */
 
-define(['uglifyjs/index'], function (uglify) {
+define(['./uglifyjs/index'], function (uglify) {
     var parser = uglify.parser,
         processor = uglify.uglify,
         ostring = Object.prototype.toString,
@@ -469,6 +469,69 @@ define(['uglifyjs/index'], function (uglify) {
         return uses;
     };
 
+
+    /**
+     * Determines if require(''), exports.x =, and/or module.exports =
+     * are used.
+     */
+    parse.usesCommonJs = function (fileName, fileContents, options) {
+        var uses = null,
+            assignsExports = false,
+            astRoot = parser.parse(fileContents);
+
+        parse.recurse(astRoot, function (prop) {
+            if (prop === 'varExports') {
+                assignsExports = true;
+            } else if (prop !== 'exports' || !assignsExports) {
+                if (!uses) {
+                    uses = {};
+                }
+                uses[prop] = true;
+            }
+        }, options, function (node, onMatch) {
+
+            var call, configNode, args;
+
+            if (!isArray(node)) {
+                return false;
+            }
+
+            if (node[0] === 'var' && node[1] && node[1][0] && node[1][0][0] === 'exports') {
+                //Hmm, a variable assignment for exports, so does not use cjs exports.
+                return onMatch('varExports');
+            } else if (node[0] === 'assign' && node[2][0] === 'dot') {
+                args = node[2][1];
+
+                if (args) {
+                    //An exports or module.exports assignment.
+                    if (args[0] === 'name' && args[1] === 'module' &&
+                        node[2][2] === 'exports') {
+                        return onMatch('moduleExports');
+                    } else if (args[0] === 'name' && args[1] === 'exports') {
+                        return onMatch('exports');
+                    }
+                }
+            } else if (node[0] === 'call') {
+                call = node[1];
+                args = node[2];
+
+                if (call) {
+                    //A require('') use.
+                    if (call[0] === 'name' && call[1] === 'require' &&
+                        args[0][0] === 'string') {
+                        return onMatch('require');
+                    }
+                }
+            }
+
+            return false;
+
+        });
+
+        return uses;
+    };
+
+
     parse.findRequireDepNames = function (node, deps) {
         var moduleName, i, n, call, args;
 
diff --git a/build/tests/parse.js b/build/tests/parse.js
@@ -122,7 +122,6 @@ define(['parse', 'env!env/file'], function (parse, file) {
     );
     doh.run();
 
-
     doh.register('parseUsesAmdOrRequireJs',
         [
             function parseUsesAmdOrRequireJs(t) {
@@ -140,15 +139,46 @@ define(['parse', 'env!env/file'], function (parse, file) {
                 t.is(true, parse.usesAmdOrRequireJs("good1", good1));
                 t.is(true, parse.usesAmdOrRequireJs("good2", good2));
                 t.is(true, parse.usesAmdOrRequireJs("good3", good3));
-                t.is(true, parse.usesAmdOrRequireJs("good4", good3));
-                t.is(true, parse.usesAmdOrRequireJs("good5", good3));
-                t.is(true, parse.usesAmdOrRequireJs("good6", good3));
-                t.is(true, parse.usesAmdOrRequireJs("good7", good3));
+                t.is(true, parse.usesAmdOrRequireJs("good4", good4));
+                t.is(true, parse.usesAmdOrRequireJs("good5", good5));
+                t.is(true, parse.usesAmdOrRequireJs("good6", good6));
+                t.is(true, parse.usesAmdOrRequireJs("good7", good7));
                 t.is(false, parse.usesAmdOrRequireJs("bad1", bad1));
                 t.is(false, parse.usesAmdOrRequireJs("bad2", bad2));
             }
         ]
     );
     doh.run();
 
+    doh.register('parseUsesCommonJs',
+        [
+            function parseUsesCommonJs(t) {
+                var good1 = "var dep = require('dep');",
+                    good2 = "something(); exports.foo = another();",
+                    good3 = "(function () { module.exports = function () {}; }());",
+                    good4 = "var a = require('a'); something(); exports.b = a;",
+
+                    bad1 = "(function(){ if (typeof define === 'function' && define.amd) { define(['some'], function (some) {}) } }());",
+                    bad2 = "require(['something']);",
+                    bad3 = "var exports; exports.foo = 'bar';",
+                    bad4 = "var exports = function () {};",
+                    result;
+
+                t.is(true, parse.usesCommonJs("good1", good1).require);
+                t.is(true, parse.usesCommonJs("good2", good2).exports);
+                t.is(true, parse.usesCommonJs("good3", good3).moduleExports);
+
+                result = parse.usesCommonJs("good4", good4);
+                t.is(true, result.require);
+                t.is(true, result.exports);
+                t.is(false, !!result.moduleExports);
+
+                t.is(null, parse.usesCommonJs("bad1", bad1));
+                t.is(null, parse.usesCommonJs("bad2", bad2));
+                t.is(null, parse.usesCommonJs("bad3", bad3));
+                t.is(null, parse.usesCommonJs("bad4", bad4));
+            }
+        ]
+    );
+    doh.run();
 });
