Add code coverage

Author: JF Paradis

.esmrc

@@ -0,0 +1,3 @@
+{
+  "cache": false
+}

.gitignore

@@ -1,3 +1,4 @@
 node_modules
 yarn.lock
-yarn-error.log
+yarn-error.log
+.nyc_output

.nycrc

@@ -0,0 +1,12 @@
+{
+  "include": [
+    "shim/src/**/*.js"
+  ],
+  "check-coverage": true,
+  "per-file": false,
+  "statements": 82,
+  "branches": 62,
+  "functions": 92,
+  "lines": 84,
+  "cache": false
+}

package.json

@@ -12,7 +12,8 @@
         "shim:build:prod": "cross-env NODE_ENV=production rollup -c shim/rollup.config.js",
         "shim:lint": "eslint ./shim/src/**/*.js ./shim/test/**/*.js",
         "shim:prettier": "prettier --config ./shim/.prettierrc --write ./shim/src/**/*.js ./shim/test/**/*.js",
-        "shim:test": "tape -r esm ./shim/test/**/*.js"
+        "shim:test": "tape -r esm ./shim/test/**/*.js",
+        "shim:coverage": "nyc --require esm tape ./shim/test/**/*.js | tap-nyc"
     },
     "repository": {
         "type": "git",
@@ -49,10 +50,12 @@
         "eslint-plugin-prettier": "^2.6.0",
         "esm": "^3.0.37",
         "forever": "^0.15.2",
+        "nyc": "^12.0.2",
         "prettier": "^1.12.1",
         "rollup": "^0.58.2",
         "rollup-plugin-babel-minify": "^4.0.0",
         "rollup-watch": "^3.2.2",
+        "tap-nyc": "^1.0.3",
         "tape": "^4.9.0"
     }
 }

shim/src/accessors.js

@@ -28,6 +28,9 @@ the bug.
 // inside each new RootRealm to fix their Object.prototypes too. So don't
 // import anything from the outside.
 
+// todo: This function is serialized and evaluated outside of the primal
+// realms and it currently can't contain code coverage metrics.
+/* istanbul ignore file */
 export function repairAccessors() {
   const { getPrototypeOf, defineProperties, defineProperty, getOwnPropertyDescriptor } = Object;
 

shim/src/evaluators.js

@@ -101,6 +101,9 @@ function createScopedEvaluatorFactory(unsafeRec, constants) {
   // back to 'false', so any instances of 'eval' in that string will get the
   // safe evaluator.
 
+  // todo: This function is serialized and evaluated outside of the primal
+  // realms and it currently can't contain code coverage metrics.
+  /* istanbul ignore next */
   return unsafeFunction(`
     with (arguments[0]) {
       ${optimizer}

shim/src/functions.js

@@ -13,6 +13,10 @@ import { defineProperty, defineProperties, getPrototypeOf, setPrototypeOf } from
  * 4. Replace its prototype property's constructor with itself
  * 5. Replace its [[Prototype]] slot with the noop constructor of Function
  */
+
+// todo: This function is serialized and evaluated outside of the primal
+// realms and it currently can't contain code coverage metrics.
+/* istanbul ignore file */
 function repairFunction(unsafeRec, functionName, functionDecl) {
   const { unsafeEval, unsafeFunction, unsafeGlobal } = unsafeRec;
 

shim/src/realmFacade.js

@@ -4,6 +4,9 @@
 // buildChildRealm is immediately turned into a string, and this function is
 // never referenced again, because it closes over the wrong intrinsics
 
+// todo: This function is serialized and evaluated outside of the primal
+// realms and it currently can't contain code coverage metrics.
+/* istanbul ignore next */
 function buildChildRealm({ initRootRealm, initCompartment, getRealmGlobal, realmEvaluate }) {
   // This Object and Reflect are brand new, from a new unsafeRec, so no user
   // code has been run or had a chance to manipulate them. We extract these