From 3d22a07ab5a986ca175f8a3415a8b847ae0c81b0 Mon Sep 17 00:00:00 2001
From: Michael Wu <michaelmwu@dropbox.com>
Date: Mon, 8 Jul 2019 16:15:18 -0700
Subject: [PATCH] docs

---
 CHANGELOG.md                        |  1 +
 packages/jest-phabricator/README.md | 24 +++++++++++++++++++++---
 2 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5c57e8fc17c7..9f1eeec07a13 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -31,6 +31,7 @@
 - `[docs]` Add information about using `jest.doMock` with ES6 imports ([#8573](https://github.com/facebook/jest/pull/8573))
 - `[docs]` Fix variable name in custom-matcher-api code example ([#8582](https://github.com/facebook/jest/pull/8582))
 - `[docs]` Fix example used in custom environment docs ([#8617](https://github.com/facebook/jest/pull/8617))
+- `[docs]` Fix example reference implementation to use Jest with Phabricator ([#8662](https://github.com/facebook/jest/pull/8662))
 
 ### Performance
 
diff --git a/packages/jest-phabricator/README.md b/packages/jest-phabricator/README.md
index 97a3fdf505be..dd23a9d414e0 100644
--- a/packages/jest-phabricator/README.md
+++ b/packages/jest-phabricator/README.md
@@ -16,6 +16,15 @@ You need to add the jest unit engine to your .arcconfig:
 ...
 ```
 
+Or use the `ArcanistConfigurationDrivenUnitTestEngine` and add an entry to your .arcunit
+
+```json
+"jest": {
+  "type": "jest",
+  "include": "(\\.jsx?$)"
+}
+```
+
 In `JestUnitTestEngine` there are a couple of constants you probably need to modify:
 
 - `PROCESSOR` points to the path or the processor
@@ -26,12 +35,16 @@ If you need to pass to Jest a custom configuration you can either use `JEST_PATH
 ## Reference implementation
 
 ```php
-class JestUnitTestEngine extends ArcanistBaseUnitTestEngine {
+final class JestUnitTestEngine extends ArcanistUnitTestEngine {
   const PROCESSOR = 'jest/packages/jest-phabricator/build/index.js';
   const JEST_PATH = 'jest/packages/jest/bin/jest.js';
   const TOO_MANY_FILES_TO_COVER = 100;
   const GIGANTIC_DIFF_THRESHOLD = 200;
 
+  public function getEngineConfigurationName() {
+    return 'jest';
+  }
+
   private function getRoot() {
     return $this->getWorkingCopy()->getProjectRoot();
   }
@@ -129,6 +142,9 @@ class JestUnitTestEngine extends ArcanistBaseUnitTestEngine {
       $results[] = $this->getFutureResults($future);
     }
 
+    if (empty($results)) {
+      return array();
+    }
     return call_user_func_array('array_merge', $results);
   }
 
@@ -141,7 +157,7 @@ class JestUnitTestEngine extends ArcanistBaseUnitTestEngine {
     $jest_paths = array();
     foreach ($paths as $path) {
       $ext = idx(pathinfo($path), 'extension');
-      if ($ext === 'js' || $ext === 'json') {
+      if ($ext === 'js' || $ext === 'json' || $ext === 'jsx') {
         // Filter deleted modules because Jest can't do anything with them.
         if (file_exists("$root/$path")) {
           $jest_paths[] = "$root/$path";
@@ -177,6 +193,7 @@ class JestUnitTestEngine extends ArcanistBaseUnitTestEngine {
     }
 
     $console->writeOut("Finished tests.\n");
+    // $console->writeErr(implode(', ', $result_arrays));
     return call_user_func_array('array_merge', $result_arrays);
   }
 
@@ -184,8 +201,8 @@ class JestUnitTestEngine extends ArcanistBaseUnitTestEngine {
     $output_JSON = $this->getOutputJSON();
     $options = array(
       '--colors',
-      '--findRelatedTests',
       '--json',
+      '--passWithNoTests true',
       '--outputFile=' . $output_JSON,
       '--testResultsProcessor=' . self::PROCESSOR
     );
@@ -194,6 +211,7 @@ class JestUnitTestEngine extends ArcanistBaseUnitTestEngine {
     // A better solution would involve knowing what's the machine buffer size limit
     // for exec and check if the command can stay within it.
     if (count($paths) < self::TOO_MANY_FILES_TO_COVER) {
+      $options[] = '--findRelatedTests ' . join(' ', $paths);
       $options[] = '--coverage';
       $options[] = '--collectCoverageOnlyFrom '. join(' ', $paths);
     }