From d2e98cb7fa67c1ae47f53b617a06d1f4872a111b Mon Sep 17 00:00:00 2001
From: blickly <blickly@google.com>
Date: Tue, 25 Apr 2017 13:54:14 -0700
Subject: [PATCH] Allow goog.module.get inside of goog.module files.

Previously, only the specific pattern of:
    let x = goog.forwardDeclare();

    function f() {
      x = goog.module.get();
    }
was supported, but goog.module.get can be generally useful without creating
the alias.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=154216580
---
 .../jscomp/ClosureRewriteModule.java          | 32 +++++++++----------
 .../jscomp/ClosureRewriteModuleTest.java      | 22 +++++++++++++
 2 files changed, 38 insertions(+), 16 deletions(-)

diff --git a/src/com/google/javascript/jscomp/ClosureRewriteModule.java b/src/com/google/javascript/jscomp/ClosureRewriteModule.java
index 1884b677f60..180248fe981 100644
--- a/src/com/google/javascript/jscomp/ClosureRewriteModule.java
+++ b/src/com/google/javascript/jscomp/ClosureRewriteModule.java
@@ -816,8 +816,9 @@ private void recordGoogModuleGet(NodeTraversal t, Node call) {
     }
 
     String aliasName = null;
-    boolean isFillingAnAlias =
-        call.getParent().isAssign() && call.getParent().getFirstChild().isName();
+    Node maybeAssign = call.getParent();
+    boolean isFillingAnAlias = maybeAssign.isAssign() && maybeAssign.getFirstChild().isName()
+        && maybeAssign.getParent().isExprResult();
     if (isFillingAnAlias && currentScript.isModule) {
       aliasName = call.getParent().getFirstChild().getString();
 
@@ -839,6 +840,12 @@ private void recordGoogModuleGet(NodeTraversal t, Node call) {
         t.report(call, INVALID_GET_ALIAS);
         return;
       }
+
+      // Each goog.module.get() calling filling an alias will have the alias importing logic
+      // handed at the goog.forwardDeclare call, and the corresponding goog.module.get can simply
+      // be removed.
+      compiler.reportChangeToEnclosingScope(maybeAssign);
+      maybeAssign.getParent().detach();
     }
   }
 
@@ -1110,20 +1117,13 @@ private void updateGoogModuleGetCall(Node call) {
     String legacyNamespace = legacyNamespaceNode.getString();
 
     compiler.reportChangeToEnclosingScope(call);
-    if (currentScript.isModule) {
-      // In a module each goog.module.get() will have a paired goog.forwardDeclare() and the module
-      // alias importing will be handled there so that the alias is available in the entire module
-      // scope.
-      NodeUtil.getEnclosingStatement(call).detach();
-    } else {
-      // In a non-module script goog.module.get() is used inside of a goog.scope() and it's
-      // imported alias need only be made available within that scope.
-      // Replace "goog.module.get('pkg.Foo');" with "module$exports$pkg$Foo;".
-      String exportedNamespace = rewriteState.getExportedNamespaceOrScript(legacyNamespace);
-      Node exportedNamespaceName = NodeUtil.newQName(compiler, exportedNamespace).srcrefTree(call);
-      exportedNamespaceName.putProp(Node.ORIGINALNAME_PROP, legacyNamespace);
-      call.replaceWith(exportedNamespaceName);
-    }
+    // Remaining calls to goog.module.get() are not alias updates,
+    // and should be replaced by a reference to the proper name.
+    // Replace "goog.module.get('pkg.Foo')" with either "pkg.Foo" or "module$exports$pkg$Foo".
+    String exportedNamespace = rewriteState.getExportedNamespaceOrScript(legacyNamespace);
+    Node exportedNamespaceName = NodeUtil.newQName(compiler, exportedNamespace).srcrefTree(call);
+    exportedNamespaceName.putProp(Node.ORIGINALNAME_PROP, legacyNamespace);
+    call.replaceWith(exportedNamespaceName);
   }
 
   private void recordExportsPropertyAssignment(NodeTraversal t, Node getpropNode) {
diff --git a/test/com/google/javascript/jscomp/ClosureRewriteModuleTest.java b/test/com/google/javascript/jscomp/ClosureRewriteModuleTest.java
index 6b80692858a..3ff19b5e528 100644
--- a/test/com/google/javascript/jscomp/ClosureRewriteModuleTest.java
+++ b/test/com/google/javascript/jscomp/ClosureRewriteModuleTest.java
@@ -932,6 +932,28 @@ public void testGoogModuleGet2() {
                 "}")});
   }
 
+  public void testGoogModuleGet3() {
+    testEs6(
+        new String[] {
+            LINE_JOINER.join(
+                "goog.module('a.b.c');",
+                "exports = class {};"),
+            LINE_JOINER.join(
+                "goog.module('x.y.z');",
+                "",
+                "function f() {",
+                "  return new (goog.module.get('a.b.c'))();",
+                "}")},
+
+        new String[] {
+            "/** @const */ var module$exports$a$b$c = class {};",
+            LINE_JOINER.join(
+                "/** @const */ var module$exports$x$y$z = {};",
+                "function module$contents$x$y$z_f() {",
+                "  return new module$exports$a$b$c();",
+                "}")});
+  }
+
   public void testAliasedGoogModuleGet1() {
     test(
         new String[] {