ember-cli-code-coverage · mukilane · Jul 24, 2025
diff --git a/packages/ember-cli-code-coverage/addon-test-support/index.js b/packages/ember-cli-code-coverage/addon-test-support/index.js
@@ -1,3 +1,5 @@
+import { helper } from '@ember/component/helper';
+
 let __require;
 
 if (typeof __webpack_require__ !== 'undefined') {
@@ -111,3 +113,29 @@ function writeCoverageInfo(data) {
     document.body.appendChild(element);
   }
 }
+
+export const emberCliCodeCoverageIncrement = helper(
+  function emberCliCodeCoverageIncrement(params, hash) {
+    let { path, statement, branch, condition, action } = hash;
+
+    if (action) {
+      return function (...arg) {
+        if (statement) {
+          window.__coverage__[path].s[statement]++;
+        }
+
+        return params[0].call(this, ...arg);
+      };
+    }
+
+    if (statement) {
+      window.__coverage__[path].s[statement]++;
+    }
+
+    if (branch && condition != null) {
+      window.__coverage__[path].b[branch][condition]++;
+    }
+
+    return params[0];
+  }
+);
diff --git a/packages/ember-cli-code-coverage/index.js b/packages/ember-cli-code-coverage/index.js
@@ -48,8 +48,10 @@ module.exports = {
       configBase = pkgJSON['ember-addon'].configPath;
     }
 
+    let config = {};
+
     if (fs.existsSync(path.join(cwd, configBase, 'coverage.js'))) {
-      let config = require(path.join(cwd, configBase, 'coverage.js'));
+      config = require(path.join(cwd, configBase, 'coverage.js'));
 
       if (config.excludes) {
         exclude = config.excludes;
@@ -90,7 +92,24 @@ module.exports = {
       // String lookup is needed to workaround https://github.com/embroider-build/embroider/issues/1525
       path.resolve(__dirname, 'lib/gjs-gts-istanbul-ignore-template-plugin'),
       [IstanbulPlugin, { cwd, include: '**/*', exclude, extension }],
-    ];
+    ].concat(
+      config.enableTemplateCoverage
+        ? [
+            [
+              // eslint-disable-next-line node/no-missing-require
+              require.resolve('babel-plugin-ember-template-compilation'),
+              {
+                transforms: [this.buildTemplatePlugin({ cwd, exclude })],
+                enableLegacyModules: [
+                  'ember-cli-htmlbars',
+                  'ember-cli-htmlbars-inline-precompile',
+                  'htmlbars-inline-precompile',
+                ],
+              },
+            ],
+          ]
+        : []
+    );
   },
 
   includedCommands() {
@@ -99,6 +118,23 @@ module.exports = {
     };
   },
 
+  _isCoverageEnabled() {
+    let config = this.project.config(process.env.EMBER_ENV)[this.name] || {};
+    return process.env[config.coverageEnvVar || 'COVERAGE'] === 'true';
+  },
+
+  treeForAddon() {
+    if (this._isCoverageEnabled()) {
+      return this._super.treeForAddon.apply(this, arguments);
+    }
+  },
+
+  treeForApp() {
+    if (this._isCoverageEnabled()) {
+      return this._super.treeForApp.apply(this, arguments);
+    }
+  },
+
   buildNamespaceMappings() {
     let rootNamespaceMappings = new Map();
     function recurse(item) {
@@ -165,4 +201,23 @@ module.exports = {
       namespaceMappings: this.buildNamespaceMappings(),
     };
   },
+
+  buildTemplatePlugin(params = {}) {
+    const buildTemplateInstrumenter = require('./lib/template-instrumenter');
+    let plugin = buildTemplateInstrumenter(params);
+
+    plugin._parallelBabel = {
+      requireFile: __filename,
+      buildUsing: 'buildTemplatePlugin',
+      params,
+    };
+    plugin.baseDir = function () {
+      return __dirname;
+    };
+    plugin.cacheKey = function () {
+      return 'template-instrumenter';
+    };
+
+    return plugin;
+  },
 };
diff --git a/packages/ember-cli-code-coverage/lib/template-coverage.js b/packages/ember-cli-code-coverage/lib/template-coverage.js
@@ -0,0 +1,70 @@
+const LINE_ENDINGS = /(?:\r\n?|\n)/;
+
+function getLocation({ loc }) {
+  return {
+    start: {
+      line: loc && loc.start.line,
+      column: loc && loc.start.column,
+    },
+    end: {
+      line: loc && loc.end.line,
+      column: loc && loc.end.column,
+    },
+  };
+}
+
+class TemplateCoverage {
+  constructor(path, contents) {
+    this.data = {
+      path,
+      s: {},
+      b: {},
+      f: {},
+      fnMap: {},
+      statementMap: {},
+      branchMap: {},
+      code: contents ? contents.split(LINE_ENDINGS) : [],
+    };
+
+    this._currentStatement = 0;
+    this._currentBranch = 0;
+  }
+
+  newStatement(node) {
+    this._currentStatement++;
+    this.data.s[this._currentStatement] = 0;
+    this.data.statementMap[this._currentStatement] = getLocation(node);
+
+    return this._currentStatement;
+  }
+
+  newBlock(node) {
+    this._currentBranch++;
+    this.data.b[this._currentBranch] = [0, 0];
+    this.data.branchMap[this._currentBranch] = {
+      loc: node.loc,
+    };
+  }
+
+  newBranch(node, type) {
+    this._currentBranch++;
+    this.data.b[this._currentBranch] = [];
+    this.data.branchMap[this._currentBranch] = {
+      type,
+      loc: node.loc,
+      locations: [],
+    };
+    return this._currentBranch;
+  }
+
+  newBranchPath(index, node) {
+    const bMeta = this.data.branchMap[index];
+    const counts = this.data.b[index];
+
+    bMeta.locations.push(getLocation(node));
+    counts.push(0);
+    return counts.length - 1;
+  }
+}
+
+module.exports = TemplateCoverage;