Update test suite to ensure 100% code coverage

.github/workflows/ci.yml

@@ -31,10 +31,16 @@ jobs:
           php-version: ${{ matrix.php }}
           coverage: xdebug
       - run: composer install
-      - run: vendor/bin/phpunit --coverage-text
+      - run: vendor/bin/phpunit --coverage-text --coverage-clover=clover.xml
         if: ${{ matrix.php >= 7.3 }}
-      - run: vendor/bin/phpunit --coverage-text -c phpunit.xml.legacy
+      - run: vendor/bin/phpunit --coverage-text --coverage-clover=clover.xml -c phpunit.xml.legacy
         if: ${{ matrix.php < 7.3 }}
+      - name: Check 100% code coverage
+        shell: php {0}
+        run: |
+          <?php
+          $metrics = simplexml_load_file('clover.xml')->project->metrics;
+          exit((int) $metrics['statements'] === (int) $metrics['coveredstatements'] ? 0 : 1);
 
   PHPUnit-hhvm:
     name: PHPUnit (HHVM)

README.md

@@ -1,6 +1,7 @@
 # clue/reactphp-stdio
 
 [![CI status](https://github.com/clue/reactphp-stdio/actions/workflows/ci.yml/badge.svg)](https://github.com/clue/reactphp-stdio/actions)
+[![code coverage](https://img.shields.io/badge/code%20coverage-100%25-success)](#tests)
 [![installs on Packagist](https://img.shields.io/packagist/dt/clue/stdio-react?color=blue&label=installs%20on%20Packagist)](https://packagist.org/packages/clue/stdio-react)
 
 Async, event-driven and UTF-8 aware console input & output (STDIN, STDOUT) for
@@ -689,6 +690,14 @@ To run the test suite, go to the project root and run:
 vendor/bin/phpunit
 ```
 
+The test suite is set up to always ensure 100% code coverage across all
+supported environments. If you have the Xdebug extension installed, you can also
+generate a code coverage report locally like this:
+
+```bash
+XDEBUG_MODE=coverage vendor/bin/phpunit --coverage-text
+```
+
 ## License
 
 This project is released under the permissive [MIT license](LICENSE).