Update CI setup to ensure 100% code coverage

Author: clue

.github/workflows/ci.yml

@@ -30,10 +30,16 @@ 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)

src/Decoder.php

@@ -116,7 +116,8 @@ public function handleData($data)
             if ($this->options === 0) {
                 $data = \json_decode($data, $this->assoc, $this->depth);
             } else {
-                $data = \json_decode($data, $this->assoc, $this->depth, $this->options);
+                assert(\PHP_VERSION_ID >= 50400);
+                $data = \json_decode($data, $this->assoc, $this->depth, $this->options); // @codeCoverageIgnore
             }
 
             // abort stream if decoding failed