fix: tia

src/Plugins/Tia.php

@@ -562,7 +562,7 @@ final class Tia implements AddsOutput, HandlesArguments, Terminable
             return $exitCode;
         }
 
-        $this->snapshotTestResults();
+        $this->snapshotTestResults(markKnownTestFiles: true);
 
         return $exitCode;
     }
@@ -1394,12 +1394,13 @@ final class Tia implements AddsOutput, HandlesArguments, Terminable
             );
         }
 
+        $graph->markKnownTestFiles(array_keys($touchedFiles));
         $graph->pruneStaleResults($this->branch, array_keys($touchedFiles), array_keys($results));
 
         $collector->reset();
     }
 
-    private function snapshotTestResults(): void
+    private function snapshotTestResults(bool $markKnownTestFiles = false): void
     {
         /** @var ResultCollector $collector */
         $collector = Container::getInstance()->get(ResultCollector::class);
@@ -1442,6 +1443,10 @@ final class Tia implements AddsOutput, HandlesArguments, Terminable
             );
         }
 
+        if ($markKnownTestFiles) {
+            $graph->markKnownTestFiles(array_keys($touchedFiles));
+        }
+
         $graph->pruneStaleResults($this->branch, array_keys($touchedFiles), array_keys($results));
 
         $this->saveGraph($graph);

src/Plugins/Tia/Graph.php

@@ -813,6 +813,38 @@ final class Graph
         }
     }
 
+    /**
+     * Mark test files that executed under a recorded coverage session as "known",
+     * seeding an empty edge set for any that produced zero project-source edges.
+     *
+     * Without this, a test that covers no application source (e.g. a pure unit
+     * test asserting on language primitives) never becomes an edge key, so
+     * {@see self::knowsTest()} reports it as unknown and it re-runs on every TIA
+     * run. Recording it with an empty edge set lets it be replayed/skipped while
+     * unchanged; it is still re-run whenever its own file changes, via
+     * {@see self::applyTestFileChanges()}.
+     *
+     * Must only be called from the recording path, where coverage was actually
+     * collected — otherwise a missing edge set could mean "coverage was off",
+     * not "genuinely covered nothing".
+     *
+     * @param  array<int, string>  $testFiles  Absolute or project-relative test file paths.
+     */
+    public function markKnownTestFiles(array $testFiles): void
+    {
+        foreach ($testFiles as $testFile) {
+            $rel = $this->relative($testFile);
+
+            if ($rel === null) {
+                continue;
+            }
+
+            if (! isset($this->edges[$rel])) {
+                $this->edges[$rel] = [];
+            }
+        }
+    }
+
     /**
      * @param  array<string, array<int, string>>  $testToTables
      */

src/Plugins/Tia/TestPaths.php

@@ -45,9 +45,7 @@ final readonly class TestPaths
                         $directories[] = $rel;
                     }
 
-                    $suffix = $directory->suffix();
-
-                    $suffixes[] = str_starts_with($suffix, '.') ? $suffix : '.'.$suffix;
+                    $suffixes[] = $directory->suffix();
                 }
 
                 foreach ($suite->files() as $file) {
@@ -61,7 +59,7 @@ final readonly class TestPaths
 
             if ($suffixes === []) {
                 foreach ($configuration->testSuffixes() as $suffix) {
-                    $suffixes[] = str_starts_with($suffix, '.') ? $suffix : '.'.$suffix;
+                    $suffixes[] = $suffix;
                 }
             }
         } catch (Throwable) {