fix memory leak (adapted from @arthirm’s ember-cli/ember-cli-htmlbars…

…-inline-precompile#112)

.npmignore

@@ -15,6 +15,7 @@ bower.json
 ember-cli-build.js
 testem.js
 yarn.lock
+node-tests
 
 # ember-try
 .node_modules.ember-try/

ember-addon-main.js

@@ -9,6 +9,29 @@ module.exports = {
 
   parentRegistry: null,
 
+  purgeModule(templateCompilerPath) {
+    // ensure we get a fresh templateCompilerModuleInstance per ember-addon
+    // instance NOTE: this is a quick hack, and will only work as long as
+    // templateCompilerPath is a single file bundle
+    //
+    // (╯°□°）╯︵ ɹǝqɯǝ
+    //
+    // we will also fix this in ember for future releases
+
+    // Module will be cached in .parent.children as well. So deleting from require.cache alone is not sufficient.
+    let mod = require.cache[templateCompilerPath];
+    if (mod && mod.parent) {
+      let index = mod.parent.children.indexOf(mod);
+      if (index >= 0) {
+        mod.parent.children.splice(index, 1);
+      } else {
+        throw new TypeError(`ember-cli-htmlbars attempted to purge '${templateCompilerPath}' but something went wrong.`);
+      }
+    }
+
+    delete require.cache[templateCompilerPath];
+  },
+
   setupPreprocessorRegistry(type, registry) {
     // ensure that broccoli-ember-hbs-template-compiler is not processing hbs files
     registry.remove('template', 'broccoli-ember-hbs-template-compiler');
@@ -64,14 +87,7 @@ module.exports = {
     let EmberENV = projectConfig.EmberENV || {};
     let templateCompilerPath = this.templateCompilerPath();
 
-    // ensure we get a fresh templateCompilerModuleInstance per ember-addon
-    // instance NOTE: this is a quick hack, and will only work as long as
-    // templateCompilerPath is a single file bundle
-    //
-    // (╯°□°）╯︵ ɹǝqɯǝ
-    //
-    // we will also fix this in ember for future releases
-    delete require.cache[templateCompilerPath];
+    this.purgeModule(templateCompilerPath);
 
     // do a full clone of the EmberENV (it is guaranteed to be structured
     // cloneable) to prevent ember-template-compiler.js from mutating
@@ -93,7 +109,8 @@ module.exports = {
       pluginCacheKey: pluginInfo.cacheKeys
     };
 
-    delete require.cache[templateCompilerPath];
+    this.purgeModule(templateCompilerPath);
+
     delete global.Ember;
     delete global.EmberENV;
 

node-tests/fixtures/compiler.js

@@ -0,0 +1,5 @@
+'use strict';
+
+module.exports = function() {
+  return 'I AM MODULE OF COMPILER';
+};

node-tests/purge-module-test.js

@@ -0,0 +1,38 @@
+'use strict';
+
+const purgeModule = require('../ember-addon-main').purgeModule;
+const expect = require('chai').expect;
+
+describe('purgeModule', function() {
+  const FIXTURE_COMPILER_PATH = require.resolve('./fixtures/compiler');
+
+  it('it works correctly', function() {
+    expect(purgeModule('asdfasdfasdfaf-unknown-file')).to.eql(undefined);
+
+    expect(require.cache[FIXTURE_COMPILER_PATH]).to.eql(undefined);
+
+    require(FIXTURE_COMPILER_PATH);
+
+    const mod = require.cache[FIXTURE_COMPILER_PATH];
+
+    expect(mod.parent).to.eql(module);
+    expect(mod.parent.children).to.include(mod);
+
+    purgeModule(FIXTURE_COMPILER_PATH);
+
+    expect(require.cache[FIXTURE_COMPILER_PATH]).to.eql(undefined);
+    expect(mod.parent.children).to.not.include(mod);
+
+    require(FIXTURE_COMPILER_PATH);
+
+    const freshModule = require.cache[FIXTURE_COMPILER_PATH];
+
+    expect(freshModule.parent).to.eql(module);
+    expect(freshModule.parent.children).to.include(freshModule);
+
+    purgeModule(FIXTURE_COMPILER_PATH);
+
+    expect(require.cache[FIXTURE_COMPILER_PATH]).to.eql(undefined);
+    expect(freshModule.parent.children).to.not.include(mod);
+  });
+});

package.json

@@ -41,6 +41,7 @@
   "devDependencies": {
     "broccoli": "^2.0.0-beta.4",
     "broccoli-concat": "^3.5.1",
+    "chai": "^4.2.0",
     "co": "^4.6.0",
     "ember-cli": "~3.3.0",
     "ember-cli-app-version": "^3.0.0",

yarn.lock

@@ -217,6 +217,10 @@ arrify@^1.0.0:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/arrify/-/arrify-1.0.1.tgz#898508da2226f380df904728456849c1501a4b0d"
 
+assertion-error@^1.1.0:
+  version "1.1.0"
+  resolved "https://registry.yarnpkg.com/assertion-error/-/assertion-error-1.1.0.tgz#e60b6b0e8f301bd97e5375215bda406c85118c0b"
+
 assign-symbols@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/assign-symbols/-/assign-symbols-1.0.0.tgz#59667f41fadd4f20ccbc2bb96b8d4f7f78ec0367"
@@ -1347,6 +1351,17 @@ center-align@^0.1.1:
     align-text "^0.1.3"
     lazy-cache "^1.0.3"
 
+chai@^4.2.0:
+  version "4.2.0"
+  resolved "https://registry.yarnpkg.com/chai/-/chai-4.2.0.tgz#760aa72cf20e3795e84b12877ce0e83737aa29e5"
+  dependencies:
+    assertion-error "^1.1.0"
+    check-error "^1.0.2"
+    deep-eql "^3.0.1"
+    get-func-name "^2.0.0"
+    pathval "^1.1.0"
+    type-detect "^4.0.5"
+
 chalk@^1.0.0, chalk@^1.1.3:
   version "1.1.3"
   resolved "https://registry.yarnpkg.com/chalk/-/chalk-1.1.3.tgz#a8115c55e4a702fe4d150abd3872822a7e09fc98"
@@ -1375,6 +1390,10 @@ charm@^1.0.0:
   dependencies:
     inherits "^2.0.1"
 
+check-error@^1.0.2:
+  version "1.0.2"
+  resolved "https://registry.yarnpkg.com/check-error/-/check-error-1.0.2.tgz#574d312edd88bb5dd8912e9286dd6c0aed4aac82"
+
 chokidar@1.7.0:
   version "1.7.0"
   resolved "https://registry.yarnpkg.com/chokidar/-/chokidar-1.7.0.tgz#798e689778151c8076b4b360e5edd28cda2bb468"
@@ -1740,6 +1759,12 @@ decompress-response@^3.3.0:
   dependencies:
     mimic-response "^1.0.0"
 
+deep-eql@^3.0.1:
+  version "3.0.1"
+  resolved "https://registry.yarnpkg.com/deep-eql/-/deep-eql-3.0.1.tgz#dfc9404400ad1c8fe023e7da1df1c147c4b444df"
+  dependencies:
+    type-detect "^4.0.0"
+
 deep-extend@^0.6.0:
   version "0.6.0"
   resolved "https://registry.yarnpkg.com/deep-extend/-/deep-extend-0.6.0.tgz#c4fa7c95404a17a9c3e8ca7e1537312b736330ac"
@@ -2905,6 +2930,10 @@ get-caller-file@^1.0.0:
   version "1.0.3"
   resolved "https://registry.yarnpkg.com/get-caller-file/-/get-caller-file-1.0.3.tgz#f978fa4c90d1dfe7ff2d6beda2a515e713bdcf4a"
 
+get-func-name@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/get-func-name/-/get-func-name-2.0.0.tgz#ead774abee72e20409433a066366023dd6887a41"
+
 get-stdin@^4.0.1:
   version "4.0.1"
   resolved "https://registry.yarnpkg.com/get-stdin/-/get-stdin-4.0.1.tgz#b968c6b0a04384324902e8bf1a5df32579a450fe"
@@ -4845,6 +4874,10 @@ path-type@^1.0.0:
     pify "^2.0.0"
     pinkie-promise "^2.0.0"
 
+pathval@^1.1.0:
+  version "1.1.0"
+  resolved "https://registry.yarnpkg.com/pathval/-/pathval-1.1.0.tgz#b942e6d4bde653005ef6b71361def8727d0645e0"
+
 pify@^2.0.0:
   version "2.3.0"
   resolved "https://registry.yarnpkg.com/pify/-/pify-2.3.0.tgz#ed141a6ac043a849ea588498e7dca8b15330e90c"
@@ -5936,6 +5969,10 @@ type-check@~0.3.2:
   dependencies:
     prelude-ls "~1.1.2"
 
+type-detect@^4.0.0, type-detect@^4.0.5:
+  version "4.0.8"
+  resolved "https://registry.yarnpkg.com/type-detect/-/type-detect-4.0.8.tgz#7646fb5f18871cfbb7749e69bd39a6388eb7450c"
+
 type-is@~1.6.15, type-is@~1.6.16:
   version "1.6.16"
   resolved "https://registry.yarnpkg.com/type-is/-/type-is-1.6.16.tgz#f89ce341541c672b25ee7ae3c73dee3b2be50194"