fix: tia

tests/.snapshots/success.txt

@@ -1821,6 +1821,11 @@
   ✓ output format → it returns a 32-character hex xxh128 hash
   ✓ output format → it returns a stable hash for empty content
 
+   PASS  Tests\Unit\Plugins\Tia\Graph
+  ✓ markKnownTestFiles() → it makes a test file with no edges known
+  ✓ markKnownTestFiles() → it does not clobber edges of an already-known test file
+  ✓ markKnownTestFiles() → it ignores paths outside the project root
+
    PASS  Tests\Unit\Plugins\Tia\IsEnabledForRun
   ✓ does not throw when an integer --random-order-seed is passed as a separate argv element
   ✓ still detects --tia when an integer argument is present
@@ -1836,6 +1841,14 @@
   ✓ it detects an added or removed non-platform dependency
   ✓ it is independent of package ordering
 
+   PASS  Tests\Unit\Plugins\Tia\TestPaths
+  ✓ isTestFile() → it matches a standard test file under a configured directory
+  ✓ isTestFile() → it does not match a non-test file that shares the directory
+  ✓ isTestFile() → it does not match files outside the configured directories
+  ✓ isTestFile() → it matches an explicitly listed file
+  ✓ isTestFile() → it honours a bare .php suffix
+  ✓ isTestFile() → it does not require a dot before the suffix
+
    PASS  Tests\Unit\Plugins\Tia\ViteDepsHelper
   ✓ it strips JSONC down to something JSON.parse accepts with ('plain-object')
   ✓ it strips JSONC down to something JSON.parse accepts with ('plain-array')
@@ -2084,4 +2097,4 @@
   ✓ pass with dataset with ('my-datas-set-value')
   ✓ within describe → pass with dataset with ('my-datas-set-value')
 
-  Tests:    1 deprecated, 4 warnings, 5 incomplete, 2 notices, 40 todos, 35 skipped, 1462 passed (3220 assertions)
+  Tests:    1 deprecated, 4 warnings, 5 incomplete, 2 notices, 40 todos, 35 skipped, 1471 passed (3232 assertions)

tests/Unit/Plugins/Tia/Graph.php

@@ -0,0 +1,37 @@
+<?php
+
+declare(strict_types=1);
+
+use Pest\Plugins\Tia\Graph;
+
+describe('markKnownTestFiles()', function (): void {
+    it('makes a test file with no edges known', function (): void {
+        $graph = new Graph(sys_get_temp_dir());
+
+        expect($graph->knowsTest('tests/Unit/ExampleTest.php'))->toBeFalse();
+
+        $graph->markKnownTestFiles(['tests/Unit/ExampleTest.php']);
+
+        expect($graph->knowsTest('tests/Unit/ExampleTest.php'))->toBeTrue();
+    });
+
+    it('does not clobber edges of an already-known test file', function (): void {
+        $graph = new Graph(sys_get_temp_dir());
+        $graph->link('tests/Feature/UserTest.php', 'app/Models/User.php');
+
+        $graph->markKnownTestFiles(['tests/Feature/UserTest.php']);
+
+        // The pre-existing edge survives — the test still depends on the source file.
+        $affected = $graph->affected(['app/Models/User.php']);
+
+        expect($affected)->toContain('tests/Feature/UserTest.php');
+    });
+
+    it('ignores paths outside the project root', function (): void {
+        $graph = new Graph(sys_get_temp_dir());
+
+        $graph->markKnownTestFiles(['/somewhere/else/tests/FooTest.php']);
+
+        expect($graph->knowsTest('/somewhere/else/tests/FooTest.php'))->toBeFalse();
+    });
+});

tests/Unit/Plugins/Tia/TestPaths.php

@@ -0,0 +1,72 @@
+<?php
+
+declare(strict_types=1);
+
+use Pest\Plugins\Tia\TestPaths;
+
+describe('isTestFile()', function (): void {
+    it('matches a standard test file under a configured directory', function (): void {
+        $paths = new TestPaths(
+            directories: ['tests/Unit', 'tests/Feature'],
+            files: [],
+            suffixes: ['Test.php'],
+        );
+
+        expect($paths->isTestFile('tests/Unit/ExampleTest.php'))->toBeTrue()
+            ->and($paths->isTestFile('tests/Feature/UserTest.php'))->toBeTrue();
+    });
+
+    it('does not match a non-test file that shares the directory', function (): void {
+        $paths = new TestPaths(
+            directories: ['tests/Unit'],
+            files: [],
+            suffixes: ['Test.php'],
+        );
+
+        expect($paths->isTestFile('tests/Unit/Helper.php'))->toBeFalse();
+    });
+
+    it('does not match files outside the configured directories', function (): void {
+        $paths = new TestPaths(
+            directories: ['tests/Unit'],
+            files: [],
+            suffixes: ['Test.php'],
+        );
+
+        expect($paths->isTestFile('app/Models/UserTest.php'))->toBeFalse();
+    });
+
+    it('matches an explicitly listed file', function (): void {
+        $paths = new TestPaths(
+            directories: [],
+            files: ['tests/Pest.php'],
+            suffixes: ['Test.php'],
+        );
+
+        expect($paths->isTestFile('tests/Pest.php'))->toBeTrue();
+    });
+
+    it('honours a bare .php suffix', function (): void {
+        $paths = new TestPaths(
+            directories: ['tests'],
+            files: [],
+            suffixes: ['.php'],
+        );
+
+        expect($paths->isTestFile('tests/Unit/ExampleTest.php'))->toBeTrue()
+            ->and($paths->isTestFile('tests/Unit/Helper.php'))->toBeTrue();
+    });
+
+    // Regression: a suffix of "Test.php" must match "ExampleTest.php". A previous
+    // normalisation prepended a dot (".Test.php"), which matched nothing and left
+    // edited tests looking unchanged to TIA, replaying stale results.
+    it('does not require a dot before the suffix', function (): void {
+        $paths = new TestPaths(
+            directories: ['tests/Unit'],
+            files: [],
+            suffixes: ['.Test.php'],
+        );
+
+        expect($paths->isTestFile('tests/Unit/ExampleTest.php'))->toBeFalse();
+    });
+});

tests/Visual/Parallel.php

@@ -24,13 +24,13 @@ test('parallel', function () use ($run): void {
         $file = file_get_contents(__FILE__);
         $file = preg_replace(
             '/\$expected = \'.*?\';/',
-            "\$expected = '1 deprecated, 4 warnings, 5 incomplete, 3 notices, 40 todos, 27 skipped, 1445 passed (3167 assertions)';",
+            "\$expected = '1 deprecated, 4 warnings, 5 incomplete, 3 notices, 40 todos, 27 skipped, 1454 passed (3179 assertions)';",
             $file,
         );
         file_put_contents(__FILE__, $file);
     }
 
-    $expected = '1 deprecated, 4 warnings, 5 incomplete, 3 notices, 40 todos, 27 skipped, 1445 passed (3167 assertions)';
+    $expected = '1 deprecated, 4 warnings, 5 incomplete, 3 notices, 40 todos, 27 skipped, 1454 passed (3179 assertions)';
 
     expect($output)
         ->toContain("Tests:    {$expected}")