From 0bc0330dc25050e8119c2ffa280a8d8188f37b84 Mon Sep 17 00:00:00 2001
From: tbreisacher <tbreisacher@google.com>
Date: Thu, 3 Nov 2016 16:52:26 -0700
Subject: [PATCH] Check @implements annotations on classes as well as
 @constructor-annotated functions.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=138136196
---
 .../jscomp/CheckRequiresForConstructors.java  | 10 ++--
 .../javascript/jscomp/MissingRequireTest.java | 50 +++++++++++++++++++
 2 files changed, 55 insertions(+), 5 deletions(-)

diff --git a/src/com/google/javascript/jscomp/CheckRequiresForConstructors.java b/src/com/google/javascript/jscomp/CheckRequiresForConstructors.java
index f42f99d65d4..f1d45c0f919 100644
--- a/src/com/google/javascript/jscomp/CheckRequiresForConstructors.java
+++ b/src/com/google/javascript/jscomp/CheckRequiresForConstructors.java
@@ -578,18 +578,18 @@ private void maybeAddGoogScopeUsage(NodeTraversal t, Node n, Node parent) {
    *      <li><pre>var foo = function() {};</pre>
    *      <li><pre>foo.bar = function() {};</pre>
    */
-  private boolean declaresFunction(Node n) {
-    if (n.isFunction()) {
+  private boolean declaresFunctionOrClass(Node n) {
+    if (n.isFunction() || n.isClass()) {
       return true;
     }
 
-    if (n.isAssign() && n.getLastChild().isFunction()) {
+    if (n.isAssign() && (n.getLastChild().isFunction() || n.getLastChild().isClass())) {
       return true;
     }
 
     if (NodeUtil.isNameDeclaration(n)
         && n.getFirstChild().hasChildren()
-        && n.getFirstFirstChild().isFunction()) {
+        && (n.getFirstFirstChild().isFunction() || n.getFirstFirstChild().isClass())) {
       return true;
     }
 
@@ -602,7 +602,7 @@ private void maybeAddJsDocUsages(NodeTraversal t, Node n) {
       return;
     }
 
-    if (declaresFunction(n)) {
+    if (declaresFunctionOrClass(n)) {
       for (JSTypeExpression expr : info.getImplementedInterfaces()) {
         maybeAddUsage(t, n, expr);
       }
diff --git a/test/com/google/javascript/jscomp/MissingRequireTest.java b/test/com/google/javascript/jscomp/MissingRequireTest.java
index dcc3ec2d74a..214e8e2ec30 100644
--- a/test/com/google/javascript/jscomp/MissingRequireTest.java
+++ b/test/com/google/javascript/jscomp/MissingRequireTest.java
@@ -448,6 +448,56 @@ public void testFailWithImplements() {
     testMissingRequire(js, warning);
   }
 
+  public void testFailWithImplements_class() {
+    setAcceptedLanguage(LanguageMode.ECMASCRIPT_NEXT);
+
+    String[] js = new String[] {
+      "var goog = {};"
+      + "goog.provide('example.Foo'); /** @interface */ example.Foo = function() {};",
+
+      "/** @implements {example.Foo} */ var SomeClass = class {};"
+    };
+    String warning = "missing require: 'example.Foo'";
+    testMissingRequire(js, warning);
+  }
+
+  public void testFailWithImplements_class2() {
+    setAcceptedLanguage(LanguageMode.ECMASCRIPT_NEXT);
+
+    String[] js = new String[] {
+      "var goog = {};"
+      + "goog.provide('example.Foo'); /** @interface */ example.Foo = function() {};",
+
+      "goog.provide('example.Bar'); /** @implements {example.Foo} */ example.Bar = class {};"
+    };
+    String warning = "missing require: 'example.Foo'";
+    testMissingRequire(js, warning);
+  }
+
+  public void testFailWithImplements_googModule() {
+    String[] js = new String[] {
+      "goog.provide('example.Interface'); /** @interface */ example.Interface = function() {};",
+
+      "goog.module('foo.Bar');"
+          + "/** @constructor @implements {example.Interface} */ function Bar() {}; exports = Bar;"
+    };
+    String warning = "missing require: 'example.Interface'";
+    testMissingRequire(js, warning);
+  }
+
+  public void testFailWithImplements_class_googModule() {
+    setAcceptedLanguage(LanguageMode.ECMASCRIPT_NEXT);
+
+    String[] js = new String[] {
+      "goog.provide('example.Interface'); /** @interface */ example.Interface = function() {};",
+
+      "goog.module('foo.Bar');"
+          + "/** @implements {example.Interface} */ class Bar {}; exports = Bar;"
+    };
+    String warning = "missing require: 'example.Interface'";
+    testMissingRequire(js, warning);
+  }
+
   public void testInterfaceExtends() {
     String js =
         LINE_JOINER.join(