ignore require() calls inside already browserified bundles

If a function expression declares a `require` parameter, its body is not
analyzed for `require()` calls. This is mostly helpful for bundles that
were already browserified, `detective` will ignore the calls to
browser-pack's require runtime.

Author: goto-bus-stop

index.js

@@ -50,6 +50,7 @@ exports.find = function (src, opts) {
     function visit(node, st, c) {
         var hasRequire = wordRe.test(src.slice(node.start, node.end));
         if (!hasRequire) return;
+        if (redefinesRequire(node)) return;
         walk.base[node.type](node, st, c);
         if (node.type !== 'CallExpression') return;
         if (isRequire(node)) {
@@ -76,6 +77,18 @@ exports.find = function (src, opts) {
         Statement: visit,
         Expression: visit
     });
+
+    // Detect `require` redefinitions in function parameter lists, like
+    // in `[function(require,module.exports){` generated by browser-pack.
+    // This is a simple way to address the 99% case without doing full scope analysis
+    function redefinesRequire(node) {
+        if (node.type === 'FunctionExpression') {
+            return node.params.some(function (param) {
+                return param.type === 'Identifier' && param.name === word;
+            });
+        }
+        return false;
+    }
 
     return modules;
 };

test/files/scope.js

@@ -0,0 +1,8 @@
+(function(modules){
+    modules[1](function(i){return modules[i]()})
+})({1:[function (require,module,exports) {
+    require('./y')
+},{'./y':2}],2:function(require,module,exports){
+    console.log("abc")
+}})
+require('./z')

test/scope.js

@@ -0,0 +1,9 @@
+var test = require('tap').test;
+var detective = require('../');
+var fs = require('fs');
+var src = fs.readFileSync(__dirname + '/files/scope.js');
+
+test('scope', function (t) {
+    t.plan(1);
+    t.deepEqual(detective(src), [ './z' ]);
+});