Clear scope cache before crawling (#2986)

packages/core/integration-tests/test/integration/scope-hoisting/es6/default-export-class-rename/a.js

@@ -0,0 +1,2 @@
+import Test from './b';
+output = Test.create();

packages/core/integration-tests/test/integration/scope-hoisting/es6/default-export-class-rename/b.js

@@ -0,0 +1,9 @@
+export default class Test {
+  constructor() {
+    this.foo = 'bar';
+  }
+
+  static create() {
+    return new Test();
+  }
+}

packages/core/integration-tests/test/integration/scope-hoisting/es6/default-export-class-rename/package.json

@@ -0,0 +1,5 @@
+{
+  "name": "default-export-class-rename",
+  "private": true,
+  "browserslist": ["last 1 Chrome version"]
+}

packages/core/integration-tests/test/scope-hoisting.js

@@ -568,6 +568,18 @@ describe('scope hoisting', function() {
       assert(!/bar/.test(contents));
       assert(!/displayName/.test(contents));
     });
+
+    it('should correctly rename references to default exported classes', async function() {
+      let b = await bundle(
+        path.join(
+          __dirname,
+          '/integration/scope-hoisting/es6/default-export-class-rename/a.js'
+        )
+      );
+
+      let output = await run(b);
+      assert.deepEqual(output.foo, 'bar');
+    });
   });
 
   describe('commonjs', function() {

packages/core/parcel-bundler/src/scope-hoisting/hoist.js

@@ -2,6 +2,7 @@ const path = require('path');
 const mm = require('micromatch');
 const t = require('@babel/types');
 const template = require('@babel/template').default;
+const traverse = require('@babel/traverse').default;
 const rename = require('./renamer');
 const {getName, getIdentifier, getExportIdentifier} = require('./utils');
 
@@ -51,6 +52,7 @@ function hasSideEffects(asset, {sideEffects} = asset._package) {
 module.exports = {
   Program: {
     enter(path, asset) {
+      traverse.cache.clearScope();
       path.scope.crawl();
 
       asset.cacheData.imports = asset.cacheData.imports || Object.create(null);