Support sideEffect: false with CommonJS (#1770)

Fixes #1699

src/scope-hoisting/hoist.js

@@ -300,8 +300,9 @@ module.exports = {
     }
 
     if (t.isIdentifier(callee, {name: 'require'})) {
+      let source = args[0].value;
       // Ignore require calls that were ignored earlier.
-      if (!asset.dependencies.has(args[0].value)) {
+      if (!asset.dependencies.has(source)) {
         return;
       }
 
@@ -316,9 +317,11 @@ module.exports = {
           p.isSequenceExpression()
       );
       if (!parent.isProgram() || bail) {
-        asset.dependencies.get(args[0].value).shouldWrap = true;
+        asset.dependencies.get(source).shouldWrap = true;
       }
 
+      asset.cacheData.imports['$require$' + source] = [source, '*'];
+
       // Generate a variable name based on the current asset id and the module name to require.
       // This will be replaced by the final variable name of the resolved asset in the packager.
       path.replaceWith(

test/integration/scope-hoisting/commonjs/side-effects-false/a.js

@@ -0,0 +1 @@
+output = require('bar').foo(3)

test/scope-hoisting.js

@@ -832,5 +832,15 @@ describe('scope hoisting', function() {
       let output = await run(b);
       assert.deepEqual(output, 3);
     });
+
+    it('should support sideEffects: false', async function() {
+      let b = await bundle(
+        __dirname +
+          '/integration/scope-hoisting/commonjs/side-effects-false/a.js'
+      );
+
+      let output = await run(b);
+      assert.deepEqual(output, 9);
+    });
   });
 });