From c35ba4d580f504aa11fa913c4f12a9e1d25e61a9 Mon Sep 17 00:00:00 2001
From: Chris Garrett <cgarrett@linkedin.com>
Date: Fri, 19 Feb 2021 13:12:06 -0800
Subject: [PATCH] Adds `useEmberModule` option

Adds an option to import `Ember` rather than relying on the global. This
will allow this babel plugin to continue working after the global has
been deprecated.
---
 __tests__/tests.js | 59 ++++++++++++++++++++++++++++++++++++++++++++++
 index.js           | 52 ++++++++++++++++++++++++++++++++++++----
 2 files changed, 107 insertions(+), 4 deletions(-)

diff --git a/__tests__/tests.js b/__tests__/tests.js
index 604e9154..ad48cbac 100644
--- a/__tests__/tests.js
+++ b/__tests__/tests.js
@@ -468,4 +468,63 @@ describe('htmlbars-inline-precompile', function () {
       expect(transformed).toContain(`hello {{firstName}}`);
     });
   });
+
+  describe('with Ember imports', function () {
+    it('adds an Ember import if useEmberModule is set to true', function () {
+      plugins = [
+        [
+          HTMLBarsInlinePrecompile,
+          {
+            precompile() {
+              return precompile.apply(this, arguments);
+            },
+
+            useEmberModule: true,
+          },
+        ],
+      ];
+
+      let transpiled = transform(
+        "import hbs from 'htmlbars-inline-precompile';\nvar compiled = hbs`hello`;"
+      );
+
+      expect(transpiled).toMatchInlineSnapshot(`
+        "import _Ember from \\"ember\\";
+
+        var compiled = _Ember.HTMLBars.template(
+        /*
+          hello
+        */
+        \\"precompiled(hello)\\");"
+      `);
+    });
+
+    it('Uses existing Ember import if one exists', function () {
+      plugins = [
+        [
+          HTMLBarsInlinePrecompile,
+          {
+            precompile() {
+              return precompile.apply(this, arguments);
+            },
+
+            useEmberModule: true,
+          },
+        ],
+      ];
+
+      let transpiled = transform(
+        "import Foo from 'ember';\nimport hbs from 'htmlbars-inline-precompile';\nvar compiled = hbs`hello`;"
+      );
+
+      expect(transpiled).toMatchInlineSnapshot(`
+        "import Foo from 'ember';
+        var compiled = Foo.HTMLBars.template(
+        /*
+          hello
+        */
+        \\"precompiled(hello)\\");"
+      `);
+    });
+  });
 });
diff --git a/index.js b/index.js
index a4be002c..e694ded1 100644
--- a/index.js
+++ b/index.js
@@ -50,7 +50,7 @@ module.exports = function (babel) {
     return result;
   }
 
-  function compileTemplate(precompile, template, _options) {
+  function compileTemplate(precompile, template, emberIdentifier, _options) {
     let options = Object.assign({ contents: template }, _options);
 
     let precompileResultString;
@@ -78,7 +78,7 @@ module.exports = function (babel) {
 
     return t.callExpression(
       t.memberExpression(
-        t.memberExpression(t.identifier('Ember'), t.identifier('HTMLBars')),
+        t.memberExpression(emberIdentifier, t.identifier('HTMLBars')),
         t.identifier('template')
       ),
       [templateExpression]
@@ -87,6 +87,44 @@ module.exports = function (babel) {
 
   return {
     visitor: {
+      Program(path, state) {
+        let options = state.opts || {};
+        let useEmberModule = Boolean(options.useEmberModule);
+
+        let preexistingEmberImportDeclaration = path
+          .get('body')
+          .filter((n) => n.type === 'ImportDeclaration')
+          .find((n) => n.get('source').get('value').node === 'ember');
+
+        if (
+          // an import was found
+          preexistingEmberImportDeclaration &&
+          // this accounts for `import from 'ember'` without a local identifier
+          preexistingEmberImportDeclaration.node.specifiers.length > 0
+        ) {
+          state.emberIdentifier = preexistingEmberImportDeclaration.node.specifiers[0].local;
+        }
+
+        state.ensureEmberImport = () => {
+          if (!useEmberModule) {
+            // ensures that we can always assume `state.emberIdentifier` is set
+            state.emberIdentifier = t.identifier('Ember');
+            return;
+          }
+
+          if (state.emberIdentifier) return;
+
+          state.emberIdentifier = path.scope.generateUidIdentifier('Ember');
+
+          let emberImport = t.importDeclaration(
+            [t.importDefaultSpecifier(state.emberIdentifier)],
+            t.stringLiteral('ember')
+          );
+
+          path.unshiftContainer('body', emberImport);
+        };
+      },
+
       ImportDeclaration(path, state) {
         let node = path.node;
 
@@ -154,7 +192,11 @@ module.exports = function (babel) {
 
         let { precompile, isProduction } = state.opts;
 
-        path.replaceWith(compileTemplate(precompile, template, { isProduction }));
+        state.ensureEmberImport();
+
+        path.replaceWith(
+          compileTemplate(precompile, template, state.emberIdentifier, { isProduction })
+        );
       },
 
       CallExpression(path, state) {
@@ -222,7 +264,9 @@ module.exports = function (babel) {
           options.isProduction = isProduction;
         }
 
-        path.replaceWith(compileTemplate(precompile, template, options));
+        state.ensureEmberImport();
+
+        path.replaceWith(compileTemplate(precompile, template, state.emberIdentifier, options));
       },
     },
   };