refactor: Use babel AST for polyfill

Author: mydea

index.js

@@ -1,15 +1,31 @@
 'use strict';
 
-const ReplaceImportsPreprocessor = require('./lib/replace-imports-preprocessor');
+const { resolve } = require('path');
 
 module.exports = {
   name: require('./package').name,
 
-  setupPreprocessorRegistry(type, registry) {
-    if (type !== 'parent') {
-      return;
-    }
+  included() {
+    this._super.included.apply(this, arguments);
 
-    registry.add('js', new ReplaceImportsPreprocessor());
+    this.patchEmberModulesAPIPolyfill();
+  },
+
+  patchEmberModulesAPIPolyfill() {
+    const babel = this.parent.findOwnAddonByName
+      ? this.parent.findOwnAddonByName('ember-cli-babel') // parent is an addon
+      : this.parent.findAddonByName('ember-cli-babel'); // parent is an app
+
+    if (babel.__CachedDecoratorPolyfillApplied) return;
+    babel.__CachedDecoratorPolyfillApplied = true;
+
+    const { _getEmberModulesAPIPolyfill } = babel;
+
+    babel._getEmberModulesAPIPolyfill = function (...args) {
+      const plugins = _getEmberModulesAPIPolyfill.apply(this, args);
+      if (!plugins) return;
+
+      return [[resolve(__dirname, './lib/transpile-modules.js')], ...plugins];
+    };
   }
 };

lib/replace-imports-preprocessor.js

@@ -0,0 +1,93 @@
+'use strict';
+
+const path = require('path');
+
+/**
+ * Based on `babel-plugin-ember-modules-api-polyfill`.
+ * @see https://github.com/ember-cli/babel-plugin-ember-modules-api-polyfill/blob/master/src/index.js
+ */
+module.exports = function (babel) {
+  const t = babel.types;
+
+  const MODULE = '@glimmer/tracking';
+  const IMPORT = 'cached';
+  const REPLACED_MODULE = 'ember-cached-decorator-polyfill';
+
+  return {
+    name: 'ember-cache-decorator-polyfill',
+    visitor: {
+      ImportDeclaration(path) {
+        let node = path.node;
+        let declarations = [];
+        let removals = [];
+        let specifiers = path.get('specifiers');
+        let importPath = node.source.value;
+
+        // Only walk specifiers if this is a module we have a mapping for
+        if (importPath === MODULE) {
+          // Iterate all the specifiers and attempt to locate their mapping
+          specifiers.forEach(specifierPath => {
+            let specifier = specifierPath.node;
+            let importName;
+
+            // imported is the name of the module being imported, e.g. import foo from bar
+            const imported = specifier.imported;
+
+            // local is the name of the module in the current scope, this is usually the same
+            // as the imported value, unless the module is aliased
+            const local = specifier.local;
+
+            // We only care about these 2 specifiers
+            if (
+              specifier.type !== 'ImportDefaultSpecifier' &&
+              specifier.type !== 'ImportSpecifier'
+            ) {
+              if (specifier.type === 'ImportNamespaceSpecifier') {
+                throw new Error(
+                  `Using \`import * as ${specifier.local.name} from '${importPath}'\` is not supported.`
+                );
+              }
+              return;
+            }
+
+            // Determine the import name, either default or named
+            if (specifier.type === 'ImportDefaultSpecifier') {
+              importName = 'default';
+            } else {
+              importName = imported.name;
+            }
+
+            if (importName !== IMPORT) return;
+
+            removals.push(specifierPath);
+
+            declarations.push(
+              t.importDeclaration(
+                [
+                  t.importSpecifier(
+                    t.identifier(local.name),
+                    t.identifier(IMPORT)
+                  )
+                ],
+                t.stringLiteral(REPLACED_MODULE)
+              )
+            );
+          });
+        }
+
+        if (removals.length > 0) {
+          if (removals.length === node.specifiers.length) {
+            path.replaceWithMultiple(declarations);
+          } else {
+            removals.forEach(specifierPath => specifierPath.remove());
+            path.insertAfter(declarations);
+          }
+        }
+      }
+    }
+  };
+};
+
+// Provide the path to the package's base directory for caching with broccoli
+// Ref: https://github.com/babel/broccoli-babel-transpiler#caching
+module.exports.baseDir = () => path.resolve(__dirname, '..');

lib/transpile-modules.js

@@ -40,7 +40,6 @@
   },
   "dependencies": {
     "@glimmer/tracking": "^1.0.4",
-    "broccoli-replace": "^2.0.2",
     "ember-cache-primitive-polyfill": "^1.0.1",
     "ember-cli-babel": "^7.21.0"
   },

package.json

@@ -0,0 +1,33 @@
+import { module, test } from 'qunit';
+import { tracked, cached as localCached } from '@glimmer/tracking';
+
+module('Unit | Import | renamed import', function () {
+  test('it works', function (assert) {
+    class Person {
+      @tracked firstName = 'Jen';
+      lastName = 'Weber';
+
+      @localCached
+      get fullName() {
+        const fullName = `${this.firstName} ${this.lastName}`;
+        assert.step(fullName);
+        return fullName;
+      }
+    }
+
+    const person = new Person();
+    assert.verifySteps([], 'getter is not called after class initialization');
+
+    assert.strictEqual(person.fullName, 'Jen Weber');
+    assert.verifySteps(
+      ['Jen Weber'],
+      'getter was called after property access'
+    );
+
+    assert.strictEqual(person.fullName, 'Jen Weber');
+    assert.verifySteps(
+      [],
+      'getter was not called again after repeated property access'
+    );
+  });
+});

tests/unit/renamed-import-test.ts

@@ -2005,17 +2005,6 @@ anymatch@~3.1.1:
     normalize-path "^3.0.0"
     picomatch "^2.0.4"
 
-applause@^2.0.0:
-  version "2.0.4"
-  resolved "https://registry.yarnpkg.com/applause/-/applause-2.0.4.tgz#0b771418fdd1bb326a225ad031d41ba0b20cd0f4"
-  integrity sha512-wFhNjSoflbAEgelX3psyKSXV2iQFjuYW31DEhcCOD/bQ98VdfltLclK4p1mI6E58Qp4Q7+5RCbBdr+Nc9b5QhA==
-  dependencies:
-    lodash "^4.17.21"
-    optional-require "^1.0.2"
-  optionalDependencies:
-    cson-parser "^4.0.8"
-    js-yaml "^4.0.0"
-
 aproba@^1.0.3, aproba@^1.1.1:
   version "1.2.0"
   resolved "https://registry.yarnpkg.com/aproba/-/aproba-1.2.0.tgz#6802e6264efd18c790a1b0d517f0f2627bf2c94a"
@@ -2036,11 +2025,6 @@ argparse@^1.0.7:
   dependencies:
     sprintf-js "~1.0.2"
 
-argparse@^2.0.1:
-  version "2.0.1"
-  resolved "https://registry.yarnpkg.com/argparse/-/argparse-2.0.1.tgz#246f50f3ca78a3240f6c997e8a9bd1eac49e4b38"
-  integrity sha512-8+9WqebbFzpX9OR+Wa6O29asIogeRMzcGtAINdpMHHyAg10f05aSFVBbcEqGf/PXw1EjAZ+q2/bEBg3DvurK3Q==
-
 arr-diff@^4.0.0:
   version "4.0.0"
   resolved "https://registry.yarnpkg.com/arr-diff/-/arr-diff-4.0.0.tgz#d6461074febfec71e7e15235761a329a5dc7c520"
@@ -3246,7 +3230,7 @@ broccoli-file-creator@^2.1.1:
     broccoli-plugin "^1.1.0"
     mkdirp "^0.5.1"
 
-broccoli-filter@^1.2.2, broccoli-filter@^1.2.3, broccoli-filter@^1.3.0:
+broccoli-filter@^1.2.2, broccoli-filter@^1.2.3:
   version "1.3.0"
   resolved "https://registry.yarnpkg.com/broccoli-filter/-/broccoli-filter-1.3.0.tgz#71e3a8e32a17f309e12261919c5b1006d6766de6"
   integrity sha512-VXJXw7eBfG82CFxaBDjYmyN7V72D4In2zwLVQJd/h3mBfF3CMdRTsv2L20lmRTtCv1sAHcB+LgMso90e/KYiLw==
@@ -3509,15 +3493,6 @@ broccoli-plugin@^4.0.1, broccoli-plugin@^4.0.2, broccoli-plugin@^4.0.3:
     rimraf "^3.0.0"
     symlink-or-copy "^1.3.0"
 
-broccoli-replace@^2.0.2:
-  version "2.0.2"
-  resolved "https://registry.yarnpkg.com/broccoli-replace/-/broccoli-replace-2.0.2.tgz#eb40046bb124a7f651486aece947ce28bbec30b1"
-  integrity sha512-1e8uyGUo8HqiKKB4oWz5nUX1rlLSRgShLxczuwSXJlmGljVWerDGF0oW5VshGAuKKYkAoDsI3Cc0TKEgo4SWTg==
-  dependencies:
-    applause "^2.0.0"
-    broccoli-filter "^1.3.0"
-    minimatch "^3.0.4"
-
 broccoli-slow-trees@^3.0.1, broccoli-slow-trees@^3.1.0:
   version "3.1.0"
   resolved "https://registry.yarnpkg.com/broccoli-slow-trees/-/broccoli-slow-trees-3.1.0.tgz#8e48903f59e061bf1213963733b9e61dec2ee5d7"
@@ -4181,11 +4156,6 @@ code-point-at@^1.0.0:
   resolved "https://registry.yarnpkg.com/code-point-at/-/code-point-at-1.1.0.tgz#0d070b4d043a5bea33a2f1a40e2edb3d9a4ccf77"
   integrity sha1-DQcLTQQ6W+ozovGkDi7bPZpMz3c=
 
-[email protected]:
-  version "1.12.7"
-  resolved "https://registry.yarnpkg.com/coffeescript/-/coffeescript-1.12.7.tgz#e57ee4c4867cf7f606bfc4a0f2d550c0981ddd27"
-  integrity sha512-pLXHFxQMPklVoEekowk8b3erNynC+DVJzChxS/LCBBgR6/8AJkHivkm//zbowcfc7BTCAjryuhx6gPqPRfsFoA==
-
 collection-visit@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/collection-visit/-/collection-visit-1.0.0.tgz#4bc0373c164bc3291b4d368c829cf1a80a59dca0"
@@ -4564,13 +4534,6 @@ crypto-random-string@^2.0.0:
   resolved "https://registry.yarnpkg.com/crypto-random-string/-/crypto-random-string-2.0.0.tgz#ef2a7a966ec11083388369baa02ebead229b30d5"
   integrity sha512-v1plID3y9r/lPhviJ1wrXpLeyUIGAZ2SHNYTEapm7/8A9nLPoyvVp3RK/EPFqn5kEznyWgYZNsRtYYIWbuG8KA==
 
-cson-parser@^4.0.8:
-  version "4.0.9"
-  resolved "https://registry.yarnpkg.com/cson-parser/-/cson-parser-4.0.9.tgz#eef0cf77edd057f97861ef800300c8239224eedb"
-  integrity sha512-I79SAcCYquWnEfXYj8hBqOOWKj6eH6zX1hhX3yqmS4K3bYp7jME3UFpHPzu3rUew0oyfc0s8T6IlWGXRAheHag==
-  dependencies:
-    coffeescript "1.12.7"
-
 [email protected], cssom@^0.3.4:
   version "0.3.8"
   resolved "https://registry.yarnpkg.com/cssom/-/cssom-0.3.8.tgz#9f1276f5b2b463f2114d3f2c75250af8c1a36f4a"
@@ -7963,13 +7926,6 @@ js-yaml@^3.13.1, js-yaml@^3.2.5, js-yaml@^3.2.7:
     argparse "^1.0.7"
     esprima "^4.0.0"
 
-js-yaml@^4.0.0:
-  version "4.1.0"
-  resolved "https://registry.yarnpkg.com/js-yaml/-/js-yaml-4.1.0.tgz#c1fb65f8f5017901cdd2c951864ba18458a10602"
-  integrity sha512-wpxZs9NoxZaJESJGIZTyDEaYpl0FKSA+FB9aJiyemKhMwkxQg63h4T1KJgUGHpTqPDNRcmmYLugrRjJlBtWvRA==
-  dependencies:
-    argparse "^2.0.1"
-
 jsbn@~0.1.0:
   version "0.1.1"
   resolved "https://registry.yarnpkg.com/jsbn/-/jsbn-0.1.1.tgz#a5e654c2e5a2deb5f201d96cefbca80c0ef2f513"
@@ -8496,11 +8452,6 @@ [email protected], lodash@^4.17.10, lodash@^4.17.11, lodash@^4.17.12, lodash@^4.17.
   resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.20.tgz#b44a9b6297bcb698f1c51a3545a2b3b368d59c52"
   integrity sha512-PlhdFcillOINfeV7Ni6oF1TAEayyZBoZ8bcshTHqOYJYlrqzRK5hagpagky5o4HfCzzd1TRkXPMFq6cKk9rGmA==
 
-lodash@^4.17.21:
-  version "4.17.21"
-  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.21.tgz#679591c564c3bffaae8454cf0b3df370c3d6911c"
-  integrity sha512-v2kDEe57lecTulaDIuNTPy3Ry4gLGJ6Z1O3vE1krgXZNrsQ+LFTGHVxVjcXPs17LhbZVGedAJv8XZ1tvj5FvSg==
-
 log-symbols@^2.2.0:
   version "2.2.0"
   resolved "https://registry.yarnpkg.com/log-symbols/-/log-symbols-2.2.0.tgz#5740e1c5d6f0dfda4ad9323b5332107ef6b4c40a"
@@ -9343,11 +9294,6 @@ onetime@^5.1.0:
   dependencies:
     mimic-fn "^2.1.0"
 
-optional-require@^1.0.2:
-  version "1.0.3"
-  resolved "https://registry.yarnpkg.com/optional-require/-/optional-require-1.0.3.tgz#275b8e9df1dc6a17ad155369c2422a440f89cb07"
-  integrity sha512-RV2Zp2MY2aeYK5G+B/Sps8lW5NHAzE5QClbFP15j+PWmP+T9PxlJXBOOLoSAdgwFvS4t0aMR4vpedMkbHfh0nA==
-
 optionator@^0.8.1:
   version "0.8.3"
   resolved "https://registry.yarnpkg.com/optionator/-/optionator-0.8.3.tgz#84fa1d036fe9d3c7e21d99884b601167ec8fb495"