feat: deprecate prefer-to-be-null rule

Author: G-Rath

README.md

@@ -184,7 +184,6 @@ installations requiring long-term consistency.
 | [prefer-spy-on](docs/rules/prefer-spy-on.md)                                 | Suggest using `jest.spyOn()`                                        |                  | ![fixable][] |
 | [prefer-strict-equal](docs/rules/prefer-strict-equal.md)                     | Suggest using `toStrictEqual()`                                     |                  | ![suggest][] |
 | [prefer-to-be](docs/rules/prefer-to-be.md)                                   | Suggest using `toBe()` for primitive literals                       |                  | ![fixable][] |
-| [prefer-to-be-null](docs/rules/prefer-to-be-null.md)                         | Suggest using `toBeNull()`                                          | ![style][]       | ![fixable][] |
 | [prefer-to-be-undefined](docs/rules/prefer-to-be-undefined.md)               | Suggest using `toBeUndefined()`                                     | ![style][]       | ![fixable][] |
 | [prefer-to-contain](docs/rules/prefer-to-contain.md)                         | Suggest using `toContain()`                                         | ![style][]       | ![fixable][] |
 | [prefer-to-have-length](docs/rules/prefer-to-have-length.md)                 | Suggest using `toHaveLength()`                                      | ![style][]       | ![fixable][] |

docs/rules/prefer-to-be-null.md

@@ -1,5 +1,9 @@
 # Suggest using `toBeNull()` (`prefer-to-be-null`)
 
+## Deprecated
+
+This rule has been deprecated in favor of [`prefer-to-be`](prefer-to-be.md).
+
 In order to have a better failure message, `toBeNull()` should be used upon
 asserting expectations on null value.
 

src/__tests__/__snapshots__/rules.test.ts.snap

@@ -42,7 +42,6 @@ Object {
       "jest/prefer-spy-on": "error",
       "jest/prefer-strict-equal": "error",
       "jest/prefer-to-be": "error",
-      "jest/prefer-to-be-null": "error",
       "jest/prefer-to-be-undefined": "error",
       "jest/prefer-to-contain": "error",
       "jest/prefer-to-have-length": "error",

src/rules/prefer-to-be-null.ts

@@ -41,6 +41,8 @@ export default createRule({
     messages: {
       useToBeNull: 'Use toBeNull() instead',
     },
+    deprecated: true,
+    replacedBy: ['prefer-to-be'],
     fixable: 'code',
     type: 'suggestion',
     schema: [],