From 200357596aed51d5a71cac0996e3a0510e507156 Mon Sep 17 00:00:00 2001
From: Sophie Alpert <git@sophiebits.com>
Date: Tue, 1 May 2018 12:46:17 -0700
Subject: [PATCH] Add error when running jest directly (#12726)
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```
$ jest
 FAIL  scripts/jest/dont-run-jest-directly.js
  ● Test suite failed to run

    Don't run `jest` directly. Run `yarn test` instead.

    > 1 | throw new Error("Don't run `jest` directly. Run `yarn test` instead.");
      2 |

      at Object.<anonymous> (scripts/jest/dont-run-jest-directly.js:1:96)

Test Suites: 1 failed, 1 total
Tests:       0 total
Snapshots:   0 total
Time:        0.866s
Ran all test suites.
```
---
 package.json                           | 3 +++
 scripts/jest/dont-run-jest-directly.js | 3 +++
 2 files changed, 6 insertions(+)
 create mode 100644 scripts/jest/dont-run-jest-directly.js

diff --git a/package.json b/package.json
index 01f0a2781f..9b625ea397 100644
--- a/package.json
+++ b/package.json
@@ -103,6 +103,9 @@
   "devEngines": {
     "node": "8.x || 9.x"
   },
+  "jest": {
+    "testRegex": "/scripts/jest/dont-run-jest-directly\\.js$"
+  },
   "scripts": {
     "build": "npm run version-check && node ./scripts/rollup/build.js",
     "flow-coverage": "flow-coverage-report --config ./.flowcoverage",
diff --git a/scripts/jest/dont-run-jest-directly.js b/scripts/jest/dont-run-jest-directly.js
new file mode 100644
index 0000000000..672d07caec
--- /dev/null
+++ b/scripts/jest/dont-run-jest-directly.js
@@ -0,0 +1,3 @@
+'use strict';
+
+throw new Error("Don't run `jest` directly. Run `yarn test` instead.");