Ignore require if it is defined (#975)

src/visitors/dependencies.js

@@ -37,7 +37,8 @@ module.exports = {
       types.isIdentifier(callee) &&
       callee.name === 'require' &&
       args.length === 1 &&
-      types.isStringLiteral(args[0]);
+      types.isStringLiteral(args[0]) &&
+      !hasBinding(ancestors, 'require');
 
     if (isRequire) {
       let optional = ancestors.some(a => types.isTryStatement(a)) || undefined;
@@ -88,6 +89,33 @@ module.exports = {
   }
 };
 
+function hasBinding(node, name) {
+  if (Array.isArray(node)) {
+    return node.some(ancestor => hasBinding(ancestor, name));
+  } else if (
+    types.isProgram(node) ||
+    types.isBlockStatement(node) ||
+    types.isBlock(node)
+  ) {
+    return node.body.some(statement => hasBinding(statement, name));
+  } else if (
+    types.isFunctionDeclaration(node) ||
+    types.isFunctionExpression(node) ||
+    types.isArrowFunctionExpression(node)
+  ) {
+    return (
+      (node.id !== null && node.id.name === name) ||
+      node.params.some(
+        param => types.isIdentifier(param) && param.name === name
+      )
+    );
+  } else if (types.isVariableDeclaration(node)) {
+    return node.declarations.some(declaration => declaration.id.name === name);
+  }
+
+  return false;
+}
+
 function addDependency(asset, node, opts = {}) {
   if (asset.options.target !== 'browser') {
     const isRelativeImport = /^[/~.]/.test(node.value);

test/integration/require-scope/index.js

@@ -0,0 +1,35 @@
+const test = {
+  unaryFnExpr: 'test failed',
+  fnExpr: 'test failed',
+  fnDecl: 'test failed',
+  varDecl: 'test failed',
+  topVarDecl: 'test failed'
+};
+
+module.exports.test = test;
+
+function main(require) {
+  require('test passed');
+}
+
+main(x => test.fnDecl = x);
+
+(function(require) {
+  require('test passed')
+})(x => test.fnExpr = x);
+
+void function main(require) {
+  require('test passed');
+}(x => test.unaryFnExpr = x);
+
+void function main() {
+  const require = x => test.varDecl = x
+
+  require('test passed')
+}()
+
+function require(x) {
+  return test.topVarDecl = x;
+}
+
+require('test passed')

test/javascript.js

@@ -711,4 +711,28 @@ describe('javascript', function() {
 
     assert.deepEqual(output, err);
   });
+
+  it('should ignore require if it is defined in the scope', async function() {
+    let b = await bundle(__dirname + '/integration/require-scope/index.js');
+
+    assertBundleTree(b, {
+      name: 'index.js',
+      assets: ['index.js'],
+      childBundles: [
+        {
+          type: 'map'
+        }
+      ]
+    });
+
+    let output = run(b);
+
+    assert.equal(typeof output.test, 'object');
+
+    let failed = Object.keys(output.test).some(
+      key => output.test[key] !== 'test passed'
+    );
+
+    assert.equal(failed, false);
+  });
 });