wip

src/Plugins/Tia.php

@@ -9,6 +9,7 @@ use Pest\Contracts\Plugins\HandlesArguments;
 use Pest\Contracts\Plugins\Terminable;
 use PHPUnit\Framework\TestStatus\TestStatus;
 use Pest\Plugins\Tia\ChangedFiles;
+use Pest\Plugins\Tia\CoverageCollector;
 use Pest\Plugins\Tia\Fingerprint;
 use Pest\Plugins\Tia\Graph;
 use Pest\Plugins\Tia\Recorder;
@@ -99,6 +100,15 @@ final class Tia implements AddsOutput, HandlesArguments, Terminable
      */
     private const string REPLAYING_GLOBAL = 'TIA_REPLAYING';
 
+    /**
+     * Global flag that tells workers to piggyback on PHPUnit's coverage
+     * driver (set by the parent whenever `--tia --coverage` is used). Workers
+     * can't infer this from their own argv because paratest forwards only
+     * `--coverage-php=<path>` — not the `--coverage` flag Pest's Coverage
+     * plugin inspects.
+     */
+    private const string PIGGYBACK_COVERAGE_GLOBAL = 'TIA_PIGGYBACK_COVERAGE';
+
     private bool $graphWritten = false;
 
     private bool $replayRan = false;
@@ -186,9 +196,26 @@ final class Tia implements AddsOutput, HandlesArguments, Terminable
         return self::tempDir().DIRECTORY_SEPARATOR.self::WORKER_RESULTS_PREFIX.'*.json';
     }
 
+    /**
+     * True when TIA is piggybacking on PHPUnit's own coverage driver. Toggled
+     * in `handleArguments` whenever `--tia` runs alongside `--coverage` so
+     * both the parent and workers read edges from the shared `CodeCoverage`
+     * instance instead of starting a second PCOV / Xdebug session.
+     */
+    private bool $piggybackCoverage = false;
+
+    /**
+     * True once we have committed to recording in this process — either by
+     * activating our own `Recorder` or by delegating to PHPUnit's coverage
+     * driver via `CoverageCollector`. `terminate()` only flushes when this
+     * is set, so runs that never entered record mode don't poke the graph.
+     */
+    private bool $recordingActive = false;
+
     public function __construct(
         private readonly OutputInterface $output,
         private readonly Recorder $recorder,
+        private readonly CoverageCollector $coverageCollector,
         private readonly WatchPatterns $watchPatterns,
     ) {}
 
@@ -249,16 +276,17 @@ final class Tia implements AddsOutput, HandlesArguments, Terminable
         $arguments = $this->popArgument(self::OPTION, $arguments);
         $arguments = $this->popArgument(self::REBUILD_OPTION, $arguments);
 
-        if ($this->coverageReportActive()) {
-            if (! $isWorker) {
-                $this->output->writeln(
-                    '  <fg=yellow>TIA</> `--coverage` is active — TIA disabled to avoid '.
-                    'conflicting with PHPUnit\'s own coverage collection.',
-                );
-            }
-
-            return $arguments;
-        }
+        // When `--coverage` is active, piggyback on PHPUnit's CodeCoverage
+        // instead of starting our own PCOV / Xdebug session. Running two
+        // collectors against the same driver corrupts both — so we let
+        // PHPUnit drive, and read per-test edges from the shared instance
+        // at the end of the run via `CoverageCollector`. Workers can't
+        // detect `--coverage` from their own argv (paratest strips it,
+        // keeping only `--coverage-php=<path>`) so the parent broadcasts
+        // via a global.
+        $this->piggybackCoverage = $isWorker
+            ? (string) Parallel::getGlobal(self::PIGGYBACK_COVERAGE_GLOBAL) === '1'
+            : $this->coverageReportActive();
 
         $projectRoot = TestSuite::getInstance()->rootPath;
 
@@ -285,17 +313,20 @@ final class Tia implements AddsOutput, HandlesArguments, Terminable
 
         $recorder = $this->recorder;
 
-        if (! $recorder->isActive()) {
+        if (! $this->recordingActive && ! $recorder->isActive()) {
             return;
         }
 
         $this->graphWritten = true;
 
         $projectRoot = TestSuite::getInstance()->rootPath;
-        $perTest = $recorder->perTestFiles();
+        $perTest = $this->piggybackCoverage
+            ? $this->coverageCollector->perTestFiles()
+            : $recorder->perTestFiles();
 
         if ($perTest === []) {
             $recorder->reset();
+            $this->coverageCollector->reset();
 
             return;
         }
@@ -303,6 +334,7 @@ final class Tia implements AddsOutput, HandlesArguments, Terminable
         if (Parallel::isWorker()) {
             $this->flushWorkerPartial($projectRoot, $perTest);
             $recorder->reset();
+            $this->coverageCollector->reset();
 
             return;
         }
@@ -330,6 +362,7 @@ final class Tia implements AddsOutput, HandlesArguments, Terminable
         ));
 
         $recorder->reset();
+        $this->coverageCollector->reset();
     }
 
     /**
@@ -472,10 +505,22 @@ final class Tia implements AddsOutput, HandlesArguments, Terminable
             }
         }
 
-        if ($graph instanceof Graph) {
+        // Force record mode whenever `--coverage` is active. Replay short-
+        // circuits tests via cached results, which would make their code
+        // paths invisible to PHPUnit's coverage driver and tank the report.
+        // A `--tia --coverage` run is the one the user wants FULL coverage
+        // from — we just harvest graph edges alongside, to feed future
+        // `--tia` (no `--coverage`) runs.
+        if ($graph instanceof Graph && ! $this->piggybackCoverage) {
             return $this->enterReplayMode($graph, $projectRoot, $arguments);
         }
 
+        if ($graph instanceof Graph && $this->piggybackCoverage) {
+            $this->output->writeln(
+                '  <fg=cyan>TIA</> `--coverage` active — running full suite and refreshing graph.',
+            );
+        }
+
         return $this->enterRecordMode($projectRoot, $arguments);
     }
 
@@ -501,6 +546,15 @@ final class Tia implements AddsOutput, HandlesArguments, Terminable
             return $arguments;
         }
 
+        // Piggyback: PHPUnit starts its coverage driver, `CoverageCollector`
+        // harvests the per-test edges in `terminate()`. The Recorder stays
+        // idle — starting our own driver would corrupt PHPUnit's data.
+        if ($this->piggybackCoverage) {
+            $this->recordingActive = true;
+
+            return $arguments;
+        }
+
         $recorder = $this->recorder;
 
         if (! $recorder->driverAvailable()) {
@@ -511,6 +565,7 @@ final class Tia implements AddsOutput, HandlesArguments, Terminable
         }
 
         $recorder->activate();
+        $this->recordingActive = true;
 
         return $arguments;
     }
@@ -656,7 +711,11 @@ final class Tia implements AddsOutput, HandlesArguments, Terminable
     {
         $recorder = $this->recorder;
 
-        if (! $recorder->driverAvailable()) {
+        // Piggyback: PHPUnit's coverage driver is already running under
+        // `--coverage`. We don't need our own driver — `CoverageCollector`
+        // harvests the per-test edges from PHPUnit's shared `CodeCoverage`
+        // at terminate time. Skip the driver check entirely in this mode.
+        if (! $this->piggybackCoverage && ! $recorder->driverAvailable()) {
             // Both series and parallel record require the coverage driver.
             // Parallel also requires it because workers inherit the parent's
             // PHP config — if the parent lacks the driver, workers will too
@@ -677,8 +736,24 @@ final class Tia implements AddsOutput, HandlesArguments, Terminable
 
             Parallel::setGlobal(self::RECORDING_GLOBAL, '1');
 
+            if ($this->piggybackCoverage) {
+                Parallel::setGlobal(self::PIGGYBACK_COVERAGE_GLOBAL, '1');
+            }
+
+            $this->output->writeln($this->piggybackCoverage
+                ? '  <fg=cyan>TIA</> recording dependency graph in parallel via `--coverage` (first run) — '.
+                    'subsequent `--tia` runs will only re-execute affected tests.'
+                : '  <fg=cyan>TIA</> recording dependency graph in parallel (first run) — '.
+                    'subsequent `--tia` runs will only re-execute affected tests.');
+
+            return $arguments;
+        }
+
+        if ($this->piggybackCoverage) {
+            $this->recordingActive = true;
+
             $this->output->writeln(
-                '  <fg=cyan>TIA</> recording dependency graph in parallel (first run) — '.
+                '  <fg=cyan>TIA</> recording dependency graph via `--coverage` (first run) — '.
                 'subsequent `--tia` runs will only re-execute affected tests.',
             );
 
@@ -686,6 +761,7 @@ final class Tia implements AddsOutput, HandlesArguments, Terminable
         }
 
         $recorder->activate();
+        $this->recordingActive = true;
 
         $this->output->writeln(sprintf(
             '  <fg=cyan>TIA</> recording dependency graph via %s (first run) — '.

src/Plugins/Tia/CoverageCollector.php

@@ -0,0 +1,152 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Pest\Plugins\Tia;
+
+use PHPUnit\Runner\CodeCoverage as PhpUnitCodeCoverage;
+use ReflectionClass;
+use Throwable;
+
+/**
+ * Extracts per-test file coverage from PHPUnit's shared `CodeCoverage`
+ * instance. Used when TIA piggybacks on `--coverage` instead of starting
+ * its own driver session — both share the same PCOV / Xdebug state, so
+ * running two recorders in parallel would corrupt each other's data.
+ *
+ * PHPUnit tags every coverage sample with the current test's id
+ * (`$test->valueObjectForEvents()->id()`, e.g. `Foo\BarTest::baz`). The
+ * per-file / per-line coverage map therefore already carries everything
+ * we need to rebuild TIA edges at the end of the run.
+ *
+ * @internal
+ */
+final class CoverageCollector
+{
+    /**
+     * Cached `className → test file` lookups. Class reflection is cheap
+     * individually but the record run can visit tens of thousands of
+     * samples, so the cache matters.
+     *
+     * @var array<string, string|null>
+     */
+    private array $classFileCache = [];
+
+    /**
+     * Rebuilds the same `absolute test file → list<absolute source file>`
+     * shape that `Recorder::perTestFiles()` exposes, so callers can treat
+     * the two collectors interchangeably when feeding the graph.
+     *
+     * @return array<string, array<int, string>>
+     */
+    public function perTestFiles(): array
+    {
+        if (! PhpUnitCodeCoverage::instance()->isActive()) {
+            return [];
+        }
+
+        try {
+            $lineCoverage = PhpUnitCodeCoverage::instance()
+                ->codeCoverage()
+                ->getData()
+                ->lineCoverage();
+        } catch (Throwable) {
+            return [];
+        }
+
+        /** @var array<string, array<string, true>> $edges */
+        $edges = [];
+
+        foreach ($lineCoverage as $sourceFile => $lines) {
+            // Collect the set of tests that hit any line in this file once,
+            // then emit one edge per (testFile, sourceFile) pair. Walking
+            // the lines per test would re-resolve the test file repeatedly.
+            $testIds = [];
+
+            foreach ($lines as $hits) {
+                if ($hits === null) {
+                    continue;
+                }
+
+                foreach ($hits as $id) {
+                    $testIds[$id] = true;
+                }
+            }
+
+            foreach (array_keys($testIds) as $testId) {
+                $testFile = $this->testIdToFile($testId);
+
+                if ($testFile === null) {
+                    continue;
+                }
+
+                $edges[$testFile][$sourceFile] = true;
+            }
+        }
+
+        $out = [];
+
+        foreach ($edges as $testFile => $sources) {
+            $out[$testFile] = array_keys($sources);
+        }
+
+        return $out;
+    }
+
+    public function reset(): void
+    {
+        $this->classFileCache = [];
+    }
+
+    private function testIdToFile(string $testId): ?string
+    {
+        // PHPUnit's test id is `ClassName::methodName` with an optional
+        // `#dataSetName` suffix for data-provider runs. Strip the dataset
+        // part — we only need the class.
+        $hash = strpos($testId, '#');
+        $identifier = $hash === false ? $testId : substr($testId, 0, $hash);
+
+        if (! str_contains($identifier, '::')) {
+            return null;
+        }
+
+        [$className] = explode('::', $identifier, 2);
+
+        if (array_key_exists($className, $this->classFileCache)) {
+            return $this->classFileCache[$className];
+        }
+
+        $file = $this->resolveClassFile($className);
+        $this->classFileCache[$className] = $file;
+
+        return $file;
+    }
+
+    private function resolveClassFile(string $className): ?string
+    {
+        if (! class_exists($className, false)) {
+            return null;
+        }
+
+        $reflection = new ReflectionClass($className);
+
+        // Pest's eval'd test classes expose the original `.php` path on a
+        // static `$__filename`. The eval'd class itself has no file of its
+        // own, so prefer this property when present.
+        if ($reflection->hasProperty('__filename')) {
+            $property = $reflection->getProperty('__filename');
+
+            if ($property->isStatic()) {
+                $value = $property->getValue();
+
+                if (is_string($value)) {
+                    return $value;
+                }
+            }
+        }
+
+        $file = $reflection->getFileName();
+
+        return is_string($file) ? $file : null;
+    }
+}