eslint: Disable jasmine env and only enable jest env for test files

Summary:
Modified the ESLint configuration to only enable the Jest environment for files we consider now tests, which are files with the `-test.js` suffix under `__tests__`. Also enabled some globals for test helpers (any file under `__tests__`).

This will allow us to catch misspelled tests, while allowing test helpers to use most Jest APIs.

Also disabled the Jasmine environment so people stop using Jasmine APIs and we can rollout Circus soon.

Reviewed By: aaronabramov

Differential Revision: D13199591

fbshipit-source-id: 12a32cf5835630b9987452b0c33d3f8085001689

.eslintrc

@@ -5,7 +5,6 @@
 
   "env": {
     "es6": true,
-    "jest": true,
   },
 
   "plugins": [
@@ -14,7 +13,7 @@
     "prettier",
     "react",
     "react-native",
-    "jest"
+    "jest",
   ],
 
   // Map from global var to bool specifying if it can be redefined
@@ -37,7 +36,6 @@
     "fetch": false,
     "FormData": false,
     "global": false,
-    "jest": false,
     "Map": true,
     "module": false,
     "navigator": false,
@@ -52,8 +50,6 @@
     "setTimeout": false,
     "window": false,
     "XMLHttpRequest": false,
-    "pit": false,
-    "jasmine": true
   },
 
   "rules": {
@@ -271,5 +267,32 @@
         "node": true,
       },
     },
+    {
+      "files": [
+        "**/__fixtures__/**/*.js",
+        "**/__mocks__/**/*.js",
+        "**/__tests__/**/*.js",
+        "jest/**/*.js",
+        "RNTester/**/*.js",
+      ],
+      "globals": {
+        // Expose some Jest globals for test helpers
+        "afterAll": true,
+        "afterEach": true,
+        "beforeAll": true,
+        "beforeEach": true,
+        "expect": true,
+        "jest": true,
+      },
+    },
+    {
+      "files": [
+        "**/__tests__/**/*-test.js",
+      ],
+      "env": {
+        "jasmine": true,
+        "jest": true,
+      },
+    },
   ],
 }

Libraries/Utilities/ReactNativeTestTools.js

@@ -8,6 +8,8 @@
  * @format
  */
 
+/* eslint-env jest */
+
 'use strict';
 
 const React = require('React');

RNTester/e2e/init.js → RNTester/e2e/__tests__/init.js

@@ -5,8 +5,10 @@
  * LICENSE file in the root directory of this source tree.
  */
 
+/* eslint-env jasmine */
+
 const detox = require('detox');
-const config = require('../../package.json').detox;
+const config = require('../../../package.json').detox;
 const adapter = require('detox/runners/jest/adapter');
 
 jest.setTimeout(480000);

RNTester/e2e/config.json

@@ -1,5 +1,5 @@
 {
-  "setupTestFrameworkScriptFile" : "./init.js",
+  "setupTestFrameworkScriptFile" : "./__tests__/init.js",
   "testEnvironment": "node",
   "bail": true,
   "verbose": true