Document differences in coverage ignore comments between providers

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

@@ -228,6 +228,12 @@ Indicates which provider should be used to instrument code for coverage. Allowed
 
 Note that using `v8` is considered experimental. This uses V8's builtin code coverage rather than one based on Babel. It is not as well tested, and it has also improved in the last few releases of Node. Using the latest versions of node (v14 at the time of this writing) will yield better results.
 
+:::note
+
+The `babel` and `v8` coverage providers use `/* istanbul ignore next */` and `/* c8 ignore next */` to exclude lines from coverage reports, respectively. For more information, you can view [the istanbuljs documentation](https://github.com/gotwarlost/istanbul/blob/f17cb56fa8664c129b497ce86c22a922a6d64d12/ignoring-code-for-coverage.md) and [the c8 documentation](https://github.com/bcoe/c8/blob/49c45b3395e3354c2463cf40247c6c8eab4bbe1c/README.md#ignoring-uncovered-lines-functions-and-blocks).
+
+:::
+
 ### `coverageReporters` \[array<string | \[string, options]>]
 
 Default: `["clover", "json", "lcov", "text"]`

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

@@ -215,6 +215,12 @@ Note that using `v8` is considered experimental. This uses V8's builtin code cov
 1. Tests needs to run in Node test environment (support for `jsdom` requires [`jest-environment-jsdom-sixteen`](https://www.npmjs.com/package/jest-environment-jsdom-sixteen))
 1. V8 has way better data in the later versions, so using the latest versions of node (v13 at the time of this writing) will yield better results
 
+:::note
+
+The `babel` and `v8` coverage providers use `/* istanbul ignore next */` and `/* c8 ignore next */` to exclude lines from coverage reports, respectively. For more information, you can view [the istanbuljs documentation](https://github.com/gotwarlost/istanbul/blob/f17cb56fa8664c129b497ce86c22a922a6d64d12/ignoring-code-for-coverage.md) and [the c8 documentation](https://github.com/bcoe/c8/blob/49c45b3395e3354c2463cf40247c6c8eab4bbe1c/README.md#ignoring-uncovered-lines-functions-and-blocks).
+
+:::
+
 ### `coverageReporters` \[array<string | \[string, options]>]
 
 Default: `["clover", "json", "lcov", "text"]`

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

@@ -216,6 +216,12 @@ Indicates which provider should be used to instrument code for coverage. Allowed
 
 Note that using `v8` is considered experimental. This uses V8's builtin code coverage rather than one based on Babel. It is not as well tested, and it has also improved in the last few releases of Node. Using the latest versions of node (v14 at the time of this writing) will yield better results.
 
+:::note
+
+The `babel` and `v8` coverage providers use `/* istanbul ignore next */` and `/* c8 ignore next */` to exclude lines from coverage reports, respectively. For more information, you can view [the istanbuljs documentation](https://github.com/gotwarlost/istanbul/blob/f17cb56fa8664c129b497ce86c22a922a6d64d12/ignoring-code-for-coverage.md) and [the c8 documentation](https://github.com/bcoe/c8/blob/49c45b3395e3354c2463cf40247c6c8eab4bbe1c/README.md#ignoring-uncovered-lines-functions-and-blocks).
+
+:::
+
 ### `coverageReporters` \[array<string | \[string, options]>]
 
 Default: `["clover", "json", "lcov", "text"]`

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

@@ -216,6 +216,12 @@ Indicates which provider should be used to instrument code for coverage. Allowed
 
 Note that using `v8` is considered experimental. This uses V8's builtin code coverage rather than one based on Babel. It is not as well tested, and it has also improved in the last few releases of Node. Using the latest versions of node (v14 at the time of this writing) will yield better results.
 
+:::note
+
+The `babel` and `v8` coverage providers use `/* istanbul ignore next */` and `/* c8 ignore next */` to exclude lines from coverage reports, respectively. For more information, you can view [the istanbuljs documentation](https://github.com/gotwarlost/istanbul/blob/f17cb56fa8664c129b497ce86c22a922a6d64d12/ignoring-code-for-coverage.md) and [the c8 documentation](https://github.com/bcoe/c8/blob/49c45b3395e3354c2463cf40247c6c8eab4bbe1c/README.md#ignoring-uncovered-lines-functions-and-blocks).
+
+:::
+
 ### `coverageReporters` \[array<string | \[string, options]>]
 
 Default: `["clover", "json", "lcov", "text"]`

website/versioned_docs/version-28.0/Configuration.md

@@ -228,6 +228,12 @@ Indicates which provider should be used to instrument code for coverage. Allowed
 
 Note that using `v8` is considered experimental. This uses V8's builtin code coverage rather than one based on Babel. It is not as well tested, and it has also improved in the last few releases of Node. Using the latest versions of node (v14 at the time of this writing) will yield better results.
 
+:::note
+
+The `babel` and `v8` coverage providers use `/* istanbul ignore next */` and `/* c8 ignore next */` to exclude lines from coverage reports, respectively. For more information, you can view [the istanbuljs documentation](https://github.com/gotwarlost/istanbul/blob/f17cb56fa8664c129b497ce86c22a922a6d64d12/ignoring-code-for-coverage.md) and [the c8 documentation](https://github.com/bcoe/c8/blob/49c45b3395e3354c2463cf40247c6c8eab4bbe1c/README.md#ignoring-uncovered-lines-functions-and-blocks).
+
+:::
+
 ### `coverageReporters` \[array<string | \[string, options]>]
 
 Default: `["clover", "json", "lcov", "text"]`

website/versioned_docs/version-28.1/Configuration.md

@@ -228,6 +228,12 @@ Indicates which provider should be used to instrument code for coverage. Allowed
 
 Note that using `v8` is considered experimental. This uses V8's builtin code coverage rather than one based on Babel. It is not as well tested, and it has also improved in the last few releases of Node. Using the latest versions of node (v14 at the time of this writing) will yield better results.
 
+:::note
+
+The `babel` and `v8` coverage providers use `/* istanbul ignore next */` and `/* c8 ignore next */` to exclude lines from coverage reports, respectively. For more information, you can view [the istanbuljs documentation](https://github.com/gotwarlost/istanbul/blob/f17cb56fa8664c129b497ce86c22a922a6d64d12/ignoring-code-for-coverage.md) and [the c8 documentation](https://github.com/bcoe/c8/blob/49c45b3395e3354c2463cf40247c6c8eab4bbe1c/README.md#ignoring-uncovered-lines-functions-and-blocks).
+
+:::
+
 ### `coverageReporters` \[array<string | \[string, options]>]
 
 Default: `["clover", "json", "lcov", "text"]`