Fix issues when using colocated component's with decorators.

The changes made in f9053bc added the ability to detect `export { Foo
as default }` along side the ability to detect `export default Foo`.
When ran in isolation (or with the `@babel/plugin-transform-typescript`)
this works fine, but in common scenarios without typescript support it
failed.

The cause of the failure is a bit difficult to grok, but _basically_ it
is because when our `ExportDefaultDeclaration` hook is hit, we add the
`setComponentTemplate` invocation. Then **subsequently** another plugin
changes from `export default Foo` to `export { Foo as default }` (the
combination of `@babel/plugin-proposal-decorators` and
`@babel/plugin-proposal-class-fields` does this), and we run the new
`ExportNamedDeclaration` which causes us to add `setComponentTemplate`
invocation **_again_**.

The fix added here ensures that _only **one**_ `setComponentTemplate`
invocation will be added (even if we see both `export default Foo` and
`export { Foo as default }` during traversal).

lib/colocated-babel-plugin.js

@@ -22,10 +22,11 @@ module.exports = function(babel) {
       },
 
       ExportDefaultDeclaration(path, state) {
-        if (!state.colocatedTemplateFound) {
+        if (state.colocatedTemplateFound !== true || state.setComponentTemplateInjected === true) {
           return;
         }
 
+        state.setComponentTemplateInjected = true;
         let defaultExportDeclaration = path.node.declaration;
         let setComponentTemplateMemberExpression = makeSetComponentTemplateMemberExpression();
         let colocatedTemplateIdentifier = makeColocatedTemplateIdentifier();
@@ -63,12 +64,13 @@ module.exports = function(babel) {
       },
 
       ExportNamedDeclaration(path, state) {
-        if (!state.colocatedTemplateFound) {
+        if (state.colocatedTemplateFound !== true || state.setComponentTemplateInjected === true) {
           return;
         }
 
         let defaultSpecifier = path.node.specifiers.find(spec => spec.exported.name === 'default');
         if (defaultSpecifier) {
+          state.setComponentTemplateInjected = true;
           path.parent.body.push(
             t.expressionStatement(
               t.callExpression(makeSetComponentTemplateMemberExpression(), [

node-tests/colocated-babel-plugin-test.js

@@ -4,10 +4,70 @@ const assert = require('assert');
 const babel = require('@babel/core');
 const { stripIndent } = require('common-tags');
 const ColocatedBabelPlugin = require('../lib/colocated-babel-plugin');
+const DecoratorsPlugin = [require.resolve('@babel/plugin-proposal-decorators'), { legacy: true }];
+const ClassPropertiesPlugin = [
+  require.resolve('@babel/plugin-proposal-class-properties'),
+  { loose: true },
+];
+const RuntimePlugin = [
+  require.resolve('@babel/plugin-transform-runtime'),
+  {
+    version: require('@babel/runtime/package').version,
+    regenerator: false,
+    useESModules: true,
+  },
+];
 
 describe('ColocatedBabelPlugin', function() {
   this.slow(500);
 
+  it('can be used with decorators', function() {
+    let { code } = babel.transformSync(
+      stripIndent`
+        import Component from '@glimmer/component';
+        const __COLOCATED_TEMPLATE__ = 'ok';
+
+        export default class MyComponent extends Component {
+          @tracked data = null;
+        };
+      `,
+      { plugins: [RuntimePlugin, ColocatedBabelPlugin, DecoratorsPlugin, ClassPropertiesPlugin] }
+    );
+
+    assert.strictEqual(
+      code,
+      stripIndent`
+        import _initializerDefineProperty from "@babel/runtime/helpers/esm/initializerDefineProperty";
+        import _applyDecoratedDescriptor from "@babel/runtime/helpers/esm/applyDecoratedDescriptor";
+        import _initializerWarningHelper from "@babel/runtime/helpers/esm/initializerWarningHelper";
+
+        var _class, _descriptor, _temp;
+
+        import Component from '@glimmer/component';
+        const __COLOCATED_TEMPLATE__ = 'ok';
+        let MyComponent = (_class = (_temp = class MyComponent extends Component {
+          constructor(...args) {
+            super(...args);
+
+            _initializerDefineProperty(this, "data", _descriptor, this);
+          }
+
+        }, _temp), (_descriptor = _applyDecoratedDescriptor(_class.prototype, "data", [tracked], {
+          configurable: true,
+          enumerable: true,
+          writable: true,
+          initializer: function () {
+            return null;
+          }
+        })), _class);
+        export { MyComponent as default };
+        ;
+
+        Ember._setComponentTemplate(__COLOCATED_TEMPLATE__, MyComponent);
+      `
+    );
+  });
+
   it('sets the template for non-class default exports', function() {
     let { code } = babel.transformSync(
       stripIndent`

package.json

@@ -49,7 +49,11 @@
   },
   "devDependencies": {
     "@babel/core": "^7.6.4",
+    "@babel/plugin-proposal-class-properties": "^7.5.5",
+    "@babel/plugin-proposal-decorators": "^7.6.0",
+    "@babel/plugin-transform-runtime": "^7.6.2",
     "@babel/plugin-transform-typescript": "^7.6.3",
+    "@babel/runtime": "^7.6.3",
     "@ember/optional-features": "^1.0.0",
     "babel-plugin-debug-macros": "^0.3.3",
     "broccoli-merge-trees": "^3.0.2",

yarn.lock

@@ -273,15 +273,15 @@
     "@babel/helper-remap-async-to-generator" "^7.1.0"
     "@babel/plugin-syntax-async-generators" "^7.2.0"
 
-"@babel/plugin-proposal-class-properties@^7.1.0", "@babel/plugin-proposal-class-properties@^7.3.4":
+"@babel/plugin-proposal-class-properties@^7.1.0", "@babel/plugin-proposal-class-properties@^7.3.4", "@babel/plugin-proposal-class-properties@^7.5.5":
   version "7.5.5"
   resolved "https://registry.yarnpkg.com/@babel/plugin-proposal-class-properties/-/plugin-proposal-class-properties-7.5.5.tgz#a974cfae1e37c3110e71f3c6a2e48b8e71958cd4"
   integrity sha512-AF79FsnWFxjlaosgdi421vmYG6/jg79bVD0dpD44QdgobzHKuLZ6S3vl8la9qIeSwGi8i1fS0O1mfuDAAdo1/A==
   dependencies:
     "@babel/helper-create-class-features-plugin" "^7.5.5"
     "@babel/helper-plugin-utils" "^7.0.0"
 
-"@babel/plugin-proposal-decorators@^7.3.0":
+"@babel/plugin-proposal-decorators@^7.3.0", "@babel/plugin-proposal-decorators@^7.6.0":
   version "7.6.0"
   resolved "https://registry.yarnpkg.com/@babel/plugin-proposal-decorators/-/plugin-proposal-decorators-7.6.0.tgz#6659d2572a17d70abd68123e89a12a43d90aa30c"
   integrity sha512-ZSyYw9trQI50sES6YxREXKu+4b7MAg6Qx2cvyDDYjP2Hpzd3FleOUwC9cqn1+za8d0A2ZU8SHujxFao956efUg==
@@ -597,6 +597,16 @@
     resolve "^1.8.1"
     semver "^5.5.1"
 
+"@babel/plugin-transform-runtime@^7.6.2":
+  version "7.6.2"
+  resolved "https://registry.yarnpkg.com/@babel/plugin-transform-runtime/-/plugin-transform-runtime-7.6.2.tgz#2669f67c1fae0ae8d8bf696e4263ad52cb98b6f8"
+  integrity sha512-cqULw/QB4yl73cS5Y0TZlQSjDvNkzDbu0FurTZyHlJpWE5T3PCMdnyV+xXoH1opr1ldyHODe3QAX3OMAii5NxA==
+  dependencies:
+    "@babel/helper-module-imports" "^7.0.0"
+    "@babel/helper-plugin-utils" "^7.0.0"
+    resolve "^1.8.1"
+    semver "^5.5.1"
+
 "@babel/plugin-transform-shorthand-properties@^7.2.0":
   version "7.2.0"
   resolved "https://registry.yarnpkg.com/@babel/plugin-transform-shorthand-properties/-/plugin-transform-shorthand-properties-7.2.0.tgz#6333aee2f8d6ee7e28615457298934a3b46198f0"
@@ -731,6 +741,13 @@
   dependencies:
     regenerator-runtime "^0.13.2"
 
+"@babel/runtime@^7.6.3":
+  version "7.6.3"
+  resolved "https://registry.yarnpkg.com/@babel/runtime/-/runtime-7.6.3.tgz#935122c74c73d2240cafd32ddb5fc2a6cd35cf1f"
+  integrity sha512-kq6anf9JGjW8Nt5rYfEuGRaEAaH1mkv3Bbu6rYvLOpPh/RusSJXuKPEAoZ7L7gybZkchE8+NV5g9vKF4AGAtsA==
+  dependencies:
+    regenerator-runtime "^0.13.2"
+
 "@babel/template@^7.1.0", "@babel/template@^7.4.4", "@babel/template@^7.6.0":
   version "7.6.0"
   resolved "https://registry.yarnpkg.com/@babel/template/-/template-7.6.0.tgz#7f0159c7f5012230dad64cca42ec9bdb5c9536e6"