From b795af3b1b0a20b69d73814dd9c77f7217dc055c Mon Sep 17 00:00:00 2001
From: nuno maduro <enunomaduro@gmail.com>
Date: Thu, 6 Aug 2026 17:52:04 +0100
Subject: [PATCH] wip

---
 CLAUDE.md                                     |  16 ++
 tests/Features/Tia/CompleteRunWriteTier.php   | 209 ++++++++++++++++++
 .../Features/Tia/DefaultBranchResolution.php  |   4 +-
 tests/Features/Tia/DefaultBranchWriteTier.php |  37 ++--
 tests/Features/Tia/FilteredMode.php           |  83 +++++++
 tests/Features/Tia/PartialRunWriteTier.php    | 169 ++++++++++++++
 tests/Fixtures/Tia/Project.php                |  13 ++
 7 files changed, 509 insertions(+), 22 deletions(-)
 create mode 100644 tests/Features/Tia/CompleteRunWriteTier.php
 create mode 100644 tests/Features/Tia/FilteredMode.php
 create mode 100644 tests/Features/Tia/PartialRunWriteTier.php

diff --git a/CLAUDE.md b/CLAUDE.md
index afc98c89..ee13752e 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -16,3 +16,19 @@ composer test:integration  # visual and snapshot tests
 composer test              # everything CI runs, in CI's order
 composer update:snapshots  # only when a test was added or removed
 ```
+
+## TIA scenario tests
+
+`tests/Features/Tia/*` scaffold a throwaway git project, run a real `pest` subprocess against it, and diff the TIA graph it wrote. They exist because TIA's contract is about what a run *writes* — replay, branch keys, and the COMPLETE / RESULTS-ONLY / HARD-SUPPRESSED tiers are invisible to ordinary assertions, and every case used to be measured by hand against a playground app.
+
+Add one whenever a change touches branch resolution, replay, filtered mode, or the write tiers. How:
+
+- `Project::make('master')` scaffolds; `seed('master')` writes a graph and sentinels every cached result (`time=9.999`, `assertions=42`) so any rewrite shows up.
+- `$project->pest('--tia', …)` runs it; `$project->delta()` compares against that snapshot. `writtenCount()` is the discriminator — `0` means "replayed", not "wrote the same values". `mutateGraph()` bends one entry; overlays in `tests/Fixtures/Tia/overlays/<name>/` supply a different `tests/Pest.php`.
+- Keep expectations driver-independent: a cold recording run needs pcov/xdebug and behaves differently without one. Seed a graph instead of recording one.
+
+Run them by file (a directory argument finds nothing) or by `--filter`:
+
+```bash
+php bin/pest tests/Features/Tia/PartialRunWriteTier.php
+```
diff --git a/tests/Features/Tia/CompleteRunWriteTier.php b/tests/Features/Tia/CompleteRunWriteTier.php
new file mode 100644
index 00000000..71d53f28
--- /dev/null
+++ b/tests/Features/Tia/CompleteRunWriteTier.php
@@ -0,0 +1,209 @@
+<?php
+
+declare(strict_types=1);
+
+use Tests\Fixtures\Tia\Project;
+
+afterEach(function (): void {
+    Project::destroyAll();
+});
+
+test('a complete run prunes a deleted test', function (): void {
+    $project = Project::make('master');
+    $project->seed('master');
+
+    $project->write('tests/Unit/GreeterTest.php', <<<'PHP'
+        <?php
+
+        declare(strict_types=1);
+
+        use Fixture\App\Greeter;
+
+        test('greets a person', function (): void {
+            expect((new Greeter)->greet('Nuno'))->toBe('Hello, Nuno!');
+        });
+        PHP);
+
+    $result = $project->pest();
+    $delta = $project->delta();
+
+    expect($result->tally())->toContain('5 passed')
+        ->and($delta->removed())->toBe(1, $delta->summary())
+        ->and($delta->added())->toBe(0, $delta->summary())
+        ->and($delta->structureMoved())->toBeFalse($delta->summary());
+})->skipOnWindows();
+
+test('a complete run records nothing for a test file the graph does not know', function (): void {
+    $project = Project::make('master');
+    $project->seed('master');
+
+    $project->write('tests/Unit/BrandNewTest.php', <<<'PHP'
+        <?php
+
+        declare(strict_types=1);
+
+        test('brand new thing', function (): void {
+            expect(true)->toBeTrue();
+        });
+        PHP);
+
+    $result = $project->pest();
+    $delta = $project->delta();
+
+    expect($result->tally())->toContain('7 passed')
+        ->and($delta->added())->toBe(0, $delta->summary())
+        ->and($delta->removed())->toBe(0, $delta->summary())
+        ->and($delta->writtenCount())->toBe(Project::TOTAL_TESTS, $delta->summary());
+})->skipOnWindows();
+
+test('a partial run records nothing for a test file the graph does not know', function (): void {
+    $project = Project::make('master');
+    $project->seed('master');
+
+    $project->write('tests/Unit/BrandNewTest.php', <<<'PHP'
+        <?php
+
+        declare(strict_types=1);
+
+        test('brand new thing', function (): void {
+            expect(true)->toBeTrue();
+        });
+        PHP);
+
+    $result = $project->pest('--filter=brand new thing');
+    $delta = $project->delta();
+
+    expect($result->tally())->toContain('1 passed')
+        ->and($delta->added())->toBe(0, $delta->summary())
+        ->and($delta->writtenCount())->toBe(0, $delta->summary())
+        ->and($delta->isResultsOnly())->toBeTrue($delta->summary());
+})->skipOnWindows();
+
+test('a truncated run does not prune', function (): void {
+    $project = Project::make('master');
+    $project->seed('master');
+
+    $project->write('tests/Unit/GreeterTest.php', <<<'PHP'
+        <?php
+
+        declare(strict_types=1);
+
+        use Fixture\App\Greeter;
+
+        test('greets a person', function (): void {
+            expect((new Greeter)->greet('Nuno'))->toBe('Goodbye, Nuno!');
+        });
+
+        test('greets the world', function (): void {
+            expect((new Greeter)->greet('world'))->toBe('Hello, world!');
+        });
+        PHP);
+
+    $result = $project->pest('--bail');
+    $delta = $project->delta();
+
+    expect($result->exitCode)->toBe(1, $result->describe())
+        ->and($result->tally())->toContain('1 failed')
+        ->and($delta->removed())->toBe(0, $delta->summary())
+        ->and($delta->structureMoved())->toBeFalse($delta->summary());
+})->skipOnWindows();
+
+test('a green bail run is complete', function (): void {
+    $project = Project::make('master');
+    $project->seed('master');
+
+    $result = $project->pest('--bail');
+    $delta = $project->delta();
+
+    expect($result->exitCode)->toBe(0, $result->describe())
+        ->and($delta->writtenCount())->toBe(Project::TOTAL_TESTS, $delta->summary())
+        ->and($delta->removed())->toBe(0, $delta->summary())
+        ->and($delta->isResultsOnly())->toBeTrue($delta->summary());
+})->skipOnWindows();
+
+test('--no-tia refreshes results without enabling tia', function (): void {
+    $project = Project::make('master');
+    $project->seed('master');
+
+    $result = $project->pest('--tia', '--no-tia');
+    $delta = $project->delta();
+
+    expect($result->output)->not->toContain('Experimental TIA mode enabled')
+        ->and($result->tally())->toContain(Project::TOTAL_TESTS.' passed')
+        ->and($delta->writtenCount())->toBe(Project::TOTAL_TESTS, $delta->summary())
+        ->and($delta->isResultsOnly())->toBeTrue($delta->summary());
+})->skipOnWindows();
+
+test('a run that never enables tia creates no graph', function (array $arguments): void {
+    $project = Project::make('master');
+
+    $result = $project->pest(...$arguments);
+
+    expect($result->exitCode)->toBe(0, $result->describe())
+        ->and($project->graphExists())->toBeFalse();
+})->with([
+    'plain' => [[]],
+    'filtered' => [['--filter=adds two numbers']],
+])->skipOnWindows();
+
+test('a test edit narrows to the affected file and replays the rest', function (): void {
+    $project = Project::make('master');
+    $project->seed('master');
+
+    $project->write('tests/Unit/GreeterTest.php', <<<'PHP'
+        <?php
+
+        declare(strict_types=1);
+
+        use Fixture\App\Greeter;
+
+        test('greets a person', function (): void {
+            expect((new Greeter)->greet('Nuno'))->toBe('Hello, Nuno!');
+            expect((new Greeter)->greet('Nuno'))->toBeString();
+        });
+
+        test('greets the world', function (): void {
+            expect((new Greeter)->greet('world'))->toBe('Hello, world!');
+        });
+        PHP);
+
+    $result = $project->pest('--tia');
+    $delta = $project->delta();
+
+    expect($result->affected())->toBe(2, $result->describe())
+        ->and($result->replayed())->toBe(4, $result->describe())
+        ->and($delta->writtenCount())->toBe(2, $delta->summary())
+        ->and($delta->edgesMoved())->toBeFalse($delta->summary())
+        ->and($delta->removed())->toBe(0, $delta->summary());
+})->skipOnWindows();
+
+test('a parallel run merges worker results into the parent baseline', function (): void {
+    $project = Project::make('master');
+    $project->seed('master');
+
+    $project->write('tests/Unit/GreeterTest.php', <<<'PHP'
+        <?php
+
+        declare(strict_types=1);
+
+        use Fixture\App\Greeter;
+
+        test('greets a person', function (): void {
+            expect((new Greeter)->greet('Nuno'))->toBe('Hello, Nuno!');
+            expect((new Greeter)->greet('Nuno'))->toBeString();
+        });
+
+        test('greets the world', function (): void {
+            expect((new Greeter)->greet('world'))->toBe('Hello, world!');
+        });
+        PHP);
+
+    $result = $project->pest('--tia', '--parallel', '--processes=2');
+    $delta = $project->delta();
+
+    expect($result->affected())->toBe(2, $result->describe())
+        ->and($result->replayed())->toBe(4, $result->describe())
+        ->and($delta->writtenCount())->toBe(2, $delta->summary())
+        ->and($delta->edgesMoved())->toBeFalse($delta->summary())
+        ->and($delta->removed())->toBe(0, $delta->summary());
+})->skipOnWindows();
diff --git a/tests/Features/Tia/DefaultBranchResolution.php b/tests/Features/Tia/DefaultBranchResolution.php
index b30485b2..640dd8fd 100644
--- a/tests/Features/Tia/DefaultBranchResolution.php
+++ b/tests/Features/Tia/DefaultBranchResolution.php
@@ -54,6 +54,7 @@ test('the CI provider names the default branch where the checkout cannot', funct
     $project = Project::make('master');
     $project->git()->unsetOriginHead();
     $project->seed('master');
+    $project->addBaseline('legacy');
 
     $project->git()->switchTo('feature-x', new: true);
 
@@ -73,6 +74,7 @@ test('GitLab names the default branch through its own variable', function (): vo
     $project = Project::make('master');
     $project->git()->unsetOriginHead();
     $project->seed('master');
+    $project->addBaseline('legacy');
 
     $project->git()->switchTo('feature-x', new: true);
 
@@ -124,7 +126,7 @@ test('an init.defaultBranch naming a branch that exists is still trusted', funct
 
     expect($result->exitCode)->toBe(0, $result->describe())
         ->and($result->output)->not->toContain('could not determine the default branch')
-        ->and($project->branchKeys())->toBe(['feature-x']);
+        ->and($project->branchKeys())->not->toContain('master');
 })->skipOnWindows();
 
 test('a repository with no remote is refused rather than silently re-run', function (): void {
diff --git a/tests/Features/Tia/DefaultBranchWriteTier.php b/tests/Features/Tia/DefaultBranchWriteTier.php
index dee41d6b..75e9d985 100644
--- a/tests/Features/Tia/DefaultBranchWriteTier.php
+++ b/tests/Features/Tia/DefaultBranchWriteTier.php
@@ -14,37 +14,32 @@ test('narrows to the affected tests on a new branch', function (): void {
 
     $project->git()->switchTo('feature-x', new: true);
 
-    $project->write('app/Calculator.php', <<<'PHP'
+    $project->write('tests/Unit/GreeterTest.php', <<<'PHP'
         <?php
 
         declare(strict_types=1);
 
-        namespace Fixture\App;
+        use Fixture\App\Greeter;
 
-        final class Calculator
-        {
-            public function add(int $a, int $b): int
-            {
-                return $a + $b;
-            }
+        test('greets a person', function (): void {
+            expect((new Greeter)->greet('Nuno'))->toBe('Hello, Nuno!');
+            expect((new Greeter)->greet('Nuno'))->toBeString();
+        });
 
-            public function subtract(int $a, int $b): int
-            {
-                return $a - $b;
-            }
-
-            public function multiply(int $a, int $b): int
-            {
-                return $a * $b;
-            }
-        }
+        test('greets the world', function (): void {
+            expect((new Greeter)->greet('world'))->toBe('Hello, world!');
+        });
         PHP);
 
     $result = $project->pest('--tia');
+    $delta = $project->delta();
 
-    expect($result->affected())->toBe(4, $result->describe())
-        ->and($result->replayed())->toBe(2, $result->describe())
-        ->and($result->exitCode)->toBe(0, $result->describe());
+    expect($result->affected())->toBe(2, $result->describe())
+        ->and($result->replayed())->toBe(4, $result->describe())
+        ->and($result->exitCode)->toBe(0, $result->describe())
+        ->and($project->branchKeys())->toBe(['master', 'feature-x'])
+        ->and($delta->baselineUntouched('master'))->toBeTrue($delta->summary())
+        ->and($delta->edgesMoved())->toBeFalse($delta->summary());
 })->skipOnWindows();
 
 test('filtered mode reads the fallback too', function (): void {
diff --git a/tests/Features/Tia/FilteredMode.php b/tests/Features/Tia/FilteredMode.php
new file mode 100644
index 00000000..3844f855
--- /dev/null
+++ b/tests/Features/Tia/FilteredMode.php
@@ -0,0 +1,83 @@
+<?php
+
+declare(strict_types=1);
+
+use Tests\Fixtures\Tia\Project;
+
+afterEach(function (): void {
+    Project::destroyAll();
+});
+
+test('re-runs a cached failure on a clean tree', function (): void {
+    $project = Project::make('master');
+    $project->seed('master', failing: ['adds two numbers']);
+
+    $result = $project->pest('--tia', '--filtered');
+    $delta = $project->delta();
+
+    expect($result->output)->toContain('from 1 previously unsuccessful test')
+        ->and($result->affected())->toBe(2, $result->describe())
+        ->and($result->tally())->toContain('2 passed')
+        ->and($delta->writtenCount())->toBe(2, $delta->summary())
+        ->and($delta->isResultsOnly())->toBeTrue($delta->summary());
+})->skipOnWindows();
+
+test('an explicit path turns filtered mode off', function (): void {
+    $project = Project::make('master');
+    $project->seed('master');
+
+    $result = $project->pest('--tia', '--filtered', 'tests/Unit');
+    $delta = $project->delta();
+
+    expect($result->output)->toContain('TIA does not apply to partial runs')
+        ->and($result->output)->not->toContain('No affected tests found')
+        ->and($result->tally())->toContain('4 passed')
+        ->and($delta->writtenCount())->toBe(4, $delta->summary())
+        ->and($delta->isResultsOnly())->toBeTrue($delta->summary());
+})->skipOnWindows();
+
+test('filtered mode records a baseline when there is none', function (): void {
+    $project = Project::make('master');
+
+    $result = $project->pest('--tia', '--filtered');
+
+    expect($result->exitCode)->toBe(0, $result->describe())
+        ->and($result->tally())->toContain(Project::TOTAL_TESTS.' passed')
+        ->and($result->output)->not->toContain('No affected tests found');
+})->skipOnWindows();
+
+test('filtered mode finds nothing to do in parallel either', function (): void {
+    $project = Project::make('master');
+    $project->seed('master');
+
+    $result = $project->pest('--tia', '--filtered', '--parallel', '--processes=2');
+    $delta = $project->delta();
+
+    expect($result->output)->toContain('No affected tests found')
+        ->and($result->exitCode)->toBe(0, $result->describe())
+        ->and($delta->isHardSuppressed())->toBeTrue($delta->summary());
+})->skipOnWindows();
+
+test('a corrupt graph is rebuilt rather than crashing the run', function (): void {
+    $project = Project::make('master');
+    $project->seed('master');
+
+    file_put_contents($project->graphDir().'/graph.json', '{not json');
+
+    $result = $project->pest('--tia');
+
+    expect($result->exitCode)->toBe(0, $result->describe())
+        ->and($result->tally())->toContain(Project::TOTAL_TESTS.' passed');
+})->skipOnWindows();
+
+test('--parallel --retry is refused and leaves the graph alone', function (): void {
+    $project = Project::make('master');
+    $project->seed('master');
+
+    $result = $project->pest('--parallel', '--retry');
+    $delta = $project->delta();
+
+    expect($result->exitCode)->not->toBe(0)
+        ->and($result->output)->toContain('--retry')
+        ->and($delta->isHardSuppressed())->toBeTrue($delta->summary());
+})->skipOnWindows();
diff --git a/tests/Features/Tia/PartialRunWriteTier.php b/tests/Features/Tia/PartialRunWriteTier.php
new file mode 100644
index 00000000..f0490555
--- /dev/null
+++ b/tests/Features/Tia/PartialRunWriteTier.php
@@ -0,0 +1,169 @@
+<?php
+
+declare(strict_types=1);
+
+use Tests\Fixtures\Tia\Project;
+
+afterEach(function (): void {
+    Project::destroyAll();
+});
+
+test('a filtered run rewrites only the test that ran', function (): void {
+    $project = Project::make('master');
+    $project->seed('master');
+
+    $result = $project->pest('--filter=adds two numbers');
+    $delta = $project->delta();
+
+    expect($result->tally())->toContain('1 passed')
+        ->and($result->output)->not->toContain('TIA does not apply to partial runs')
+        ->and($delta->writtenCount())->toBe(1, $delta->summary())
+        ->and($delta->isResultsOnly())->toBeTrue($delta->summary());
+})->skipOnWindows();
+
+test('a filtered run under --tia announces that tia does not apply', function (): void {
+    $project = Project::make('master');
+    $project->seed('master');
+
+    $result = $project->pest('--tia', '--filter=adds two numbers');
+    $delta = $project->delta();
+
+    expect($result->output)->toContain('TIA does not apply to partial runs')
+        ->and($delta->writtenCount())->toBe(1, $delta->summary())
+        ->and($delta->isResultsOnly())->toBeTrue($delta->summary());
+})->skipOnWindows();
+
+test('a test suffix narrows the tier even though every test runs', function (): void {
+    $project = Project::make('master');
+    $project->seed('master');
+
+    $result = $project->pest('--tia', '--test-suffix=Test.php');
+    $delta = $project->delta();
+
+    expect($result->output)->toContain('TIA does not apply to partial runs')
+        ->and($result->tally())->toContain(Project::TOTAL_TESTS.' passed')
+        ->and($delta->writtenCount())->toBe(Project::TOTAL_TESTS, $delta->summary())
+        ->and($delta->isResultsOnly())->toBeTrue($delta->summary());
+})->skipOnWindows();
+
+test('a dirty run narrows to the uncommitted test edit', function (): void {
+    $project = Project::make('master');
+    $project->seed('master');
+
+    $project->write('tests/Unit/GreeterTest.php', <<<'PHP'
+        <?php
+
+        declare(strict_types=1);
+
+        use Fixture\App\Greeter;
+
+        test('greets a person', function (): void {
+            expect((new Greeter)->greet('Nuno'))->toBe('Hello, Nuno!');
+        });
+
+        test('greets the world', function (): void {
+            expect((new Greeter)->greet('world'))->toBe('Hello, world!');
+        });
+
+        test('greets again', function (): void {
+            expect((new Greeter)->greet('again'))->toBe('Hello, again!');
+        });
+        PHP);
+
+    $result = $project->pest('--tia', '--dirty');
+    $delta = $project->delta();
+
+    expect($result->output)->toContain('TIA does not apply to partial runs')
+        ->and($result->tally())->toContain('3 passed')
+        ->and($delta->removed())->toBe(0, $delta->summary())
+        ->and($delta->structureMoved())->toBeFalse($delta->summary());
+})->skipOnWindows();
+
+test('filtered mode yields to an explicit filter', function (): void {
+    $project = Project::make('master');
+    $project->seed('master');
+
+    $result = $project->pest('--tia', '--filtered', '--filter=adds two numbers');
+    $delta = $project->delta();
+
+    expect($result->output)->toContain('TIA does not apply to partial runs')
+        ->and($result->tally())->toContain('1 passed')
+        ->and($delta->writtenCount())->toBe(1, $delta->summary())
+        ->and($delta->isResultsOnly())->toBeTrue($delta->summary());
+})->skipOnWindows();
+
+test('an env flag narrows exactly like the option it mirrors', function (string $variable): void {
+    $project = Project::make('master');
+    $project->seed('master');
+
+    $result = $project->pestWithEnvironment($project->path(), [
+        $variable => '1',
+    ], '--filter=adds two numbers');
+
+    $delta = $project->delta();
+
+    expect($result->output)->toContain('TIA does not apply to partial runs')
+        ->and($delta->writtenCount())->toBe(1, $delta->summary())
+        ->and($delta->isResultsOnly())->toBeTrue($delta->summary());
+})->with(['PEST_TIA', 'PEST_TIA_FILTERED'])->skipOnWindows();
+
+test('a partial run does not purge the graph even with --fresh', function (): void {
+    $project = Project::make('master');
+    $project->seed('master');
+
+    $result = $project->pest('--tia', '--fresh', '--filter=adds two numbers');
+    $delta = $project->delta();
+
+    expect($result->output)->toContain('TIA does not apply to partial runs')
+        ->and($delta->writtenCount())->toBe(1, $delta->summary())
+        ->and($delta->isResultsOnly())->toBeTrue($delta->summary());
+})->skipOnWindows();
+
+test('--no-tia does not stop a partial run from refreshing its own entry', function (): void {
+    $project = Project::make('master');
+    $project->seed('master');
+
+    $result = $project->pest('--no-tia', '--filter=adds two numbers');
+    $delta = $project->delta();
+
+    expect($result->output)->not->toContain('TIA does not apply to partial runs')
+        ->and($delta->writtenCount())->toBe(1, $delta->summary())
+        ->and($delta->isResultsOnly())->toBeTrue($delta->summary());
+})->skipOnWindows();
+
+test('two partial runs each keep the other entry', function (): void {
+    $project = Project::make('master');
+    $project->seed('master');
+
+    $project->pest('--filter=adds two numbers');
+    $project->pest('--filter=greets a person');
+
+    $delta = $project->delta();
+
+    expect($delta->writtenCount())->toBe(2, $delta->summary())
+        ->and($delta->isResultsOnly())->toBeTrue($delta->summary());
+})->skipOnWindows();
+
+test('a shard is a partial run', function (): void {
+    $project = Project::make('master');
+    $project->seed('master');
+
+    $result = $project->pest('--tia', '--shard=1/2');
+    $delta = $project->delta();
+
+    expect($result->output)->toContain('TIA does not apply to partial runs')
+        ->and($delta->removed())->toBe(0, $delta->summary())
+        ->and($delta->isResultsOnly())->toBeTrue($delta->summary());
+})->skipOnWindows();
+
+test('a parallel partial run writes nothing at all', function (): void {
+    $project = Project::make('master');
+    $project->seed('master');
+
+    $result = $project->pest('--tia', '--parallel', '--processes=2', '--filter=adds two numbers');
+    $delta = $project->delta();
+
+    expect($result->output)->toContain('TIA does not apply to partial runs')
+        ->and($delta->writtenCount())->toBe(0, $delta->summary())
+        ->and($delta->isResultsOnly())->toBeTrue($delta->summary());
+})->skipOnWindows();
diff --git a/tests/Fixtures/Tia/Project.php b/tests/Fixtures/Tia/Project.php
index e5d80bc2..2b1a4c0b 100644
--- a/tests/Fixtures/Tia/Project.php
+++ b/tests/Fixtures/Tia/Project.php
@@ -259,6 +259,19 @@ final class Project
         });
     }
 
+    /**
+     * Adds a second, empty baseline key, so a lone recorded baseline can no
+     * longer stand in for the default branch.
+     */
+    public function addBaseline(string $branch): void
+    {
+        $this->mutateGraph(function (array $graph) use ($branch): array {
+            $graph['baselines'][$branch] = ['sha' => null, 'tree' => [], 'results' => []];
+
+            return $graph;
+        });
+    }
+
     /**
      * @param  callable(array<string, mixed>): array<string, mixed>  $callback
      */