Merge pull request #231 from mfn/mfn-logger-detect-ci

The Github Actions logger is now automatically detected

src/guide/command-line-options.md

@@ -153,7 +153,9 @@ Can significantly improve performance since fewer Mutants are generated in compa
 
 ### `--logger-github`
 
-Supposed to be used only with GitHub Actions. This logger prints GitHub Annotation warnings for escaped Mutants right in the Pull Request:
+Supposed to be used only with GitHub Actions. This logger prints GitHub Annotation warnings for escaped Mutants right in the Pull Request.
+
+<p class="tip">Note that the Github Actions environment is automatically detected and this switch isn't actually necessary when executed there.</p>
 
 ![GitHub Annotation Escaped Mutant](/images/github-logger.png)
 

src/guide/usage.md

@@ -86,7 +86,7 @@ You can commit it to the VCS and, if necessary, override it locally by creating
   * `json` - machine-readable file in JSON format. Can be programmatically analyzed. In addition to general stats, contains original, mutated code, diff and test framework output for each Mutant.
   * `perMutator` - a markdown file which will give a break-down of the effectiveness of each mutator.  
   Each of the above logs accept a local filename to write to (eg `infection.log`), or you can write to the terminal using `php://stdout` or `php://stderr`, this can be useful in CI to store the mutation results in the output.
-  * `github` - prints GitHub Annotation warnings right in the Pull Request. Supposed to be used with GitHub Actions. See [`--logger-github`](/guide/command-line-options.html#logger-github)
+  * `github` - prints GitHub Annotation warnings right in the Pull Request. Supposed to be used with GitHub Actions. See [`--logger-github`](/guide/command-line-options.html#logger-github), but usually not necessary as it is automatically detected.
 * `tmpDir` - Optional. It's a folder where Infection creates its configs, caches and other stuff. It may be useful for people who doesn't have access to the default system temporary folder and/or doesn't have write permissions. Either absolute `/tmp/folder` or relative `var/cache` paths can be used.
 * `phpUnit` - optional key
   * `configDir` - custom directory path with `phpunit.xml.dist` file. This is useful for example for old Symfony app, where `phpunit.xml.dist` is located at `./app`