Metro: Keep from naively seeing all requires as commonjs requires.

Reviewed By: mjesun

Differential Revision: D7992887

fbshipit-source-id: b54f910d0c3430e067660c32ab8df04c59999b21

packages/metro/src/ModuleGraph/worker/__tests__/collectDependencies-test.js

@@ -215,6 +215,49 @@ it('exposes a string as `dependencyMapName` even without collecting dependencies
   expect(collectDependencies(ast, opts).dependencyMapName).toEqual(any(String));
 });
 
+it('ignores require functions defined defined by lower scopes', () => {
+  const ast = astFromCode(`
+    const a = require('b/lib/a');
+    exports.do = () => require("do");
+    if (!something) {
+      require("setup/something");
+    }
+    require('do');
+    function testA(require) {
+      const b = require('nonExistantModule');
+    }
+    {
+      const require = function(foo) {
+        return;
+      }
+      require('nonExistantModule');
+    }
+  `);
+  const {dependencies, dependencyMapName} = collectDependencies(ast, opts);
+  expect(dependencies).toEqual([
+    {name: 'b/lib/a', isAsync: false},
+    {name: 'do', isAsync: false},
+    {name: 'setup/something', isAsync: false},
+  ]);
+  expect(codeFromAst(ast)).toEqual(
+    comparableCode(`
+      const a = require(${dependencyMapName}[0], 'b/lib/a');
+      exports.do = () => require(${dependencyMapName}[1], "do");
+      if (!something) {
+        require(${dependencyMapName}[2], "setup/something");
+      }
+      require(${dependencyMapName}[1], 'do');
+      function testA(require) {
+        const b = require('nonExistantModule');
+      }
+      {
+        const require = function (foo) { return; };
+        require('nonExistantModule');
+      }
+    `),
+  );
+});
+
 function astFromCode(code) {
   return babylon.parse(code, {plugins: ['dynamicImport']});
 }

packages/metro/src/ModuleGraph/worker/collectDependencies.js

@@ -74,7 +74,7 @@ function collectDependencies(
         processImportCall(context, path, node, depMapIdent);
         return;
       }
-      if (isRequireCall(node.callee)) {
+      if (isNativeRequireCall(path)) {
         const reqNode = processRequireCall(context, path, node, depMapIdent);
         visited.add(reqNode);
       }
@@ -88,8 +88,14 @@ function collectDependencies(
   };
 }
 
-function isRequireCall(callee) {
-  return callee.type === 'Identifier' && callee.name === 'require';
+function isNativeRequireCall(path) {
+  const node = path.node;
+  const callee = node.callee;
+  return (
+    callee.type === 'Identifier' &&
+    callee.name === 'require' &&
+    path.scope.bindings['require'] == null
+  );
 }
 
 function processImportCall(context, path, node, depMapIdent) {