Document differences in coverage ignore comments between providers (#…

…12836)

Co-authored-by: Tom Mrazauskas <tom@mrazauskas.de>

CHANGELOG.md

@@ -10,6 +10,7 @@
 
 - `[docs]` Updated docs to indicate that `jest-environment-jsdom` is a separate package [#12828](https://github.com/facebook/jest/issues/12828)
 - `[jest-haste-map]` Bump `walker` version ([#12324](https://github.com/facebook/jest/pull/12324))
+- `[docs]` Document the comments used by coverage providers [#12835](https://github.com/facebook/jest/issues/12835)
 
 ### Performance
 

docs/Configuration.md

@@ -158,6 +158,14 @@ Default: `false`
 
 Indicates whether the coverage information should be collected while executing the test. Because this retrofits all executed files with coverage collection statements, it may significantly slow down your tests.
 
+Jest ships with two coverage providers: `babel` (default) and `v8`. See the [`coverageProvider`](#coverageprovider-string) option for more details.
+
+:::note
+
+The `babel` and `v8` coverage providers use `/* istanbul ignore next */` and `/* c8 ignore next */` comments to exclude lines from coverage reports, respectively. For more information, you can view the [`istanbuljs` documentation](https://github.com/istanbuljs/nyc#parsing-hints-ignoring-lines) and the [`c8` documentation](https://github.com/bcoe/c8#ignoring-uncovered-lines-functions-and-blocks).
+
+:::
+
 ### `collectCoverageFrom` \[array]
 
 Default: `undefined`

website/versioned_docs/version-25.x/Configuration.md

@@ -141,6 +141,14 @@ Default: `false`
 
 Indicates whether the coverage information should be collected while executing the test. Because this retrofits all executed files with coverage collection statements, it may significantly slow down your tests.
 
+Jest ships with two coverage providers: `babel` (default) and `v8`. See the [`coverageProvider`](#coverageprovider-string) option for more details.
+
+:::note
+
+The `babel` and `v8` coverage providers use `/* istanbul ignore next */` and `/* c8 ignore next */` comments to exclude lines from coverage reports, respectively. For more information, you can view the [`istanbuljs` documentation](https://github.com/istanbuljs/nyc#parsing-hints-ignoring-lines) and the [`c8` documentation](https://github.com/bcoe/c8#ignoring-uncovered-lines-functions-and-blocks).
+
+:::
+
 ### `collectCoverageFrom` \[array]
 
 Default: `undefined`

website/versioned_docs/version-26.x/Configuration.md

@@ -154,6 +154,14 @@ Default: `false`
 
 Indicates whether the coverage information should be collected while executing the test. Because this retrofits all executed files with coverage collection statements, it may significantly slow down your tests.
 
+Jest ships with two coverage providers: `babel` (default) and `v8`. See the [`coverageProvider`](#coverageprovider-string) option for more details.
+
+:::note
+
+The `babel` and `v8` coverage providers use `/* istanbul ignore next */` and `/* c8 ignore next */` comments to exclude lines from coverage reports, respectively. For more information, you can view the [`istanbuljs` documentation](https://github.com/istanbuljs/nyc#parsing-hints-ignoring-lines) and the [`c8` documentation](https://github.com/bcoe/c8#ignoring-uncovered-lines-functions-and-blocks).
+
+:::
+
 ### `collectCoverageFrom` \[array]
 
 Default: `undefined`

website/versioned_docs/version-27.x/Configuration.md

@@ -154,6 +154,14 @@ Default: `false`
 
 Indicates whether the coverage information should be collected while executing the test. Because this retrofits all executed files with coverage collection statements, it may significantly slow down your tests.
 
+Jest ships with two coverage providers: `babel` (default) and `v8`. See the [`coverageProvider`](#coverageprovider-string) option for more details.
+
+:::note
+
+The `babel` and `v8` coverage providers use `/* istanbul ignore next */` and `/* c8 ignore next */` comments to exclude lines from coverage reports, respectively. For more information, you can view the [`istanbuljs` documentation](https://github.com/istanbuljs/nyc#parsing-hints-ignoring-lines) and the [`c8` documentation](https://github.com/bcoe/c8#ignoring-uncovered-lines-functions-and-blocks).
+
+:::
+
 ### `collectCoverageFrom` \[array]
 
 Default: `undefined`

website/versioned_docs/version-28.0/Configuration.md

@@ -158,6 +158,14 @@ Default: `false`
 
 Indicates whether the coverage information should be collected while executing the test. Because this retrofits all executed files with coverage collection statements, it may significantly slow down your tests.
 
+Jest ships with two coverage providers: `babel` (default) and `v8`. See the [`coverageProvider`](#coverageprovider-string) option for more details.
+
+:::note
+
+The `babel` and `v8` coverage providers use `/* istanbul ignore next */` and `/* c8 ignore next */` comments to exclude lines from coverage reports, respectively. For more information, you can view the [`istanbuljs` documentation](https://github.com/istanbuljs/nyc#parsing-hints-ignoring-lines) and the [`c8` documentation](https://github.com/bcoe/c8#ignoring-uncovered-lines-functions-and-blocks).
+
+:::
+
 ### `collectCoverageFrom` \[array]
 
 Default: `undefined`

website/versioned_docs/version-28.1/Configuration.md

@@ -158,6 +158,14 @@ Default: `false`
 
 Indicates whether the coverage information should be collected while executing the test. Because this retrofits all executed files with coverage collection statements, it may significantly slow down your tests.
 
+Jest ships with two coverage providers: `babel` (default) and `v8`. See the [`coverageProvider`](#coverageprovider-string) option for more details.
+
+:::note
+
+The `babel` and `v8` coverage providers use `/* istanbul ignore next */` and `/* c8 ignore next */` comments to exclude lines from coverage reports, respectively. For more information, you can view the [`istanbuljs` documentation](https://github.com/istanbuljs/nyc#parsing-hints-ignoring-lines) and the [`c8` documentation](https://github.com/bcoe/c8#ignoring-uncovered-lines-functions-and-blocks).
+
+:::
+
 ### `collectCoverageFrom` \[array]
 
 Default: `undefined`