Added code to make tests fail fast.

homework-5/package.json

@@ -44,6 +44,7 @@
     "setupFilesAfterEnv": [
       "./src/setupTests.js"
     ],
+    "testEnvironment": "./src/testing/failFast.js",
     "transform": {}
   },
   "//": [

homework-5/src/testing/failFast.js

+import jestEnvironmentNode from 'jest-environment-node';
+
+export default class FailFastEnvironment extends jestEnvironmentNode.default {
+  constructor(...rest) {
+    super(...rest);
+    this.failed = false;
+  }
+
+  async handleTestEvent(event, state) {
+    switch (event.name) {
+    case 'hook_failure':
+    case 'test_fn_failure':
+      this.failed = true;
+      break;
+    case 'test_start':
+      if (this.failed) {
+        event.test.mode = 'skip';
+      }
+      break;
+    default:
+    }
+    if (super.handleTestEvent !== undefined) {
+      await super.handleTestEvent(event, state);
+    }
+  }
+}