feat(jest-cli): add forceExitAfterTestRun avg

After run all tests that force exit when forceExitAfterTestRun is true

jestjs#1456

packages/jest-cli/src/cli/args.js

@@ -261,6 +261,13 @@ const options = {
       'Will run all tests affected by file changes in the last commit made.',
     type: 'boolean',
   },
+  forceExitAfterTestRun: {
+    default: false,
+    description:
+      'Force Jest to exit after all tests have completed running. ' +
+      'This is useful when resources set up by test code cannot be adequately cleaned up.',
+    type: 'boolean',
+  },
 };
 
 module.exports = {

packages/jest-cli/src/cli/index.js

@@ -39,7 +39,10 @@ function run(argv?: Object, root?: Path) {
   }
 
   getJest(root).runCLI(argv, root, result => {
-    process.on('exit', () => process.exit(!result || result.success ? 0 : 1));
+    const success = !result || result.success;
+    process.on('exit', () => process.exit(success ? 0 : 1));
+
+    if (argv.forceExitAfterTestRun === true) process.exit(success ? 0 : 1);
   });
 }