Use a directory in the operating system's path used for temporary files for caching information from static analysis needed for code coverage when no cache directory is explicitly configured

Author: sebastianbergmann

ChangeLog-12.1.md

@@ -12,7 +12,8 @@ All notable changes of the PHPUnit 12.1 release series are documented in this fi
 
 ### Changed
 
-* The static analysis of first-party source files required for the code coverage functionality is now performed before the first test is run, if code coverage processing is requested (via the XML configuration file and/or CLI options) and all first-party source files are configured to be processed (which is the default). This has the same effect as running `phpunit --warm-coverage-cache` before running tests.
+* When code coverage processing is requested and no static analysis cache directory has been configured then a cache directory in the operating system's path used for temporary files is automatically created and used
+* The static analysis of first-party source files required for the code coverage functionality is now performed before the first test is run, if code coverage processing is requested (via the XML configuration file and/or CLI options), all first-party source files are configured to be processed (which is the default), and a static analysis cache directory is available (either explicitly configured or automatically determined, see above). This has the same effect as running `phpunit --warm-coverage-cache` before running tests.
 
 ### Deprecated
 

src/Runner/CodeCoverage.php

@@ -12,11 +12,13 @@
 use function assert;
 use function file_put_contents;
 use function sprintf;
+use function sys_get_temp_dir;
 use PHPUnit\Event\Facade as EventFacade;
 use PHPUnit\Framework\TestCase;
 use PHPUnit\TextUI\Configuration\CodeCoverageFilterRegistry;
 use PHPUnit\TextUI\Configuration\Configuration;
 use PHPUnit\TextUI\Output\Printer;
+use PHPUnit\Util\Filesystem;
 use SebastianBergmann\CodeCoverage\Driver\Driver;
 use SebastianBergmann\CodeCoverage\Driver\Selector;
 use SebastianBergmann\CodeCoverage\Exception as CodeCoverageException;
@@ -80,7 +82,17 @@ public function init(Configuration $configuration, CodeCoverageFilterRegistry $c
         }
 
         if ($configuration->hasCoverageCacheDirectory()) {
-            $this->codeCoverage()->cacheStaticAnalysis($configuration->coverageCacheDirectory());
+            $coverageCacheDirectory = $configuration->coverageCacheDirectory();
+        } else {
+            $candidate = sys_get_temp_dir() . '/phpunit-code-coverage-cache';
+
+            if (Filesystem::createDirectory($candidate)) {
+                $coverageCacheDirectory = $candidate;
+            }
+        }
+
+        if (isset($coverageCacheDirectory)) {
+            $this->codeCoverage()->cacheStaticAnalysis($coverageCacheDirectory);
         }
 
         $this->codeCoverage()->excludeSubclassesOfThisClassFromUnintentionallyCoveredCodeCheck(Comparator::class);
@@ -121,11 +133,11 @@ public function init(Configuration $configuration, CodeCoverageFilterRegistry $c
             $this->deactivate();
         }
 
-        if ($configuration->hasCoverageCacheDirectory() && $configuration->includeUncoveredFiles()) {
+        if (isset($coverageCacheDirectory) && $configuration->includeUncoveredFiles()) {
             EventFacade::emitter()->testRunnerStartedStaticAnalysisForCodeCoverage();
 
             $statistics = (new CacheWarmer)->warmCache(
-                $configuration->coverageCacheDirectory(),
+                $coverageCacheDirectory,
                 !$configuration->disableCodeCoverageIgnore(),
                 $configuration->ignoreDeprecatedCodeUnitsFromCodeCoverage(),
                 $codeCoverageFilterRegistry->get(),

tests/end-to-end/event/invalid-coverage-metadata.phpt

@@ -21,6 +21,8 @@ PHPUnit Started (PHPUnit %s using %s)
 Test Runner Configured
 Event Facade Sealed
 Test Suite Loaded (1 test)
+Static Analysis for Code Coverage Started
+Static Analysis for Code Coverage Finished (0 cache hits, 1 cache misses)
 Test Runner Started
 Test Suite Sorted
 Test Runner Execution Started (1 test)