From 740064ced79a69ae74523e36e1e6a8956b274dca Mon Sep 17 00:00:00 2001
From: Erlend Tobiassen <regiontog@users.noreply.github.com>
Date: Mon, 20 Jan 2020 03:32:05 +0100
Subject: [PATCH] Fix missing ClassDeclaration references after scope#crawl
 (#11011)

* Bug replication test

* Simplify test

* Fixes #10896

* Merge path.crawl `ClassDeclaration` and `Declaration` visitors

Merged to avoid subtle assumption that `Declaration` is called before `ClassDeclaration`

* Move registartion of class id in crawl to BlockScoped

* Add some assertions to crawl test
---
 packages/babel-traverse/src/scope/index.js | 16 +++++++++-------
 packages/babel-traverse/test/scope.js      | 14 ++++++++++++++
 2 files changed, 23 insertions(+), 7 deletions(-)

diff --git a/packages/babel-traverse/src/scope/index.js b/packages/babel-traverse/src/scope/index.js
index 9f9d786673..7ba6793be3 100644
--- a/packages/babel-traverse/src/scope/index.js
+++ b/packages/babel-traverse/src/scope/index.js
@@ -128,15 +128,17 @@ const collectorVisitor = {
   BlockScoped(path) {
     let scope = path.scope;
     if (scope.path === path) scope = scope.parent;
-    scope.getBlockParent().registerDeclaration(path);
-  },
 
-  ClassDeclaration(path) {
-    const id = path.node.id;
-    if (!id) return;
+    const parent = scope.getBlockParent();
+    parent.registerDeclaration(path);
 
-    const name = id.name;
-    path.scope.bindings[name] = path.scope.getBinding(name);
+    // Register class identifier in class' scope if this is a class declaration.
+    if (path.isClassDeclaration() && path.node.id) {
+      const id = path.node.id;
+      const name = id.name;
+
+      path.scope.bindings[name] = path.scope.parent.getBinding(name);
+    }
   },
 
   Block(path) {
diff --git a/packages/babel-traverse/test/scope.js b/packages/babel-traverse/test/scope.js
index b796dbf682..d4115b1c9e 100644
--- a/packages/babel-traverse/test/scope.js
+++ b/packages/babel-traverse/test/scope.js
@@ -289,6 +289,20 @@ describe("scope", () => {
         column: 32,
       });
     });
+
+    it("class identifier available in class scope after crawl", function() {
+      const path = getPath("class a { build() { return new a(); } }");
+
+      path.scope.crawl();
+
+      let referencePaths = path.scope.bindings.a.referencePaths;
+      expect(referencePaths).toHaveLength(1);
+
+      referencePaths = path.get("body[0]").scope.bindings.a.referencePaths;
+      expect(referencePaths).toHaveLength(1);
+
+      expect(path.scope.bindings.a).toBe(path.get("body[0]").scope.bindings.a);
+    });
   });
 
   describe("duplicate bindings", () => {