Add NativePipeRunner and PipePipelineService with multi-step pipeline functionality and tests

Author: rcalicdan

tests/Fixtures/Pipes/NativePipeRunner.php

@@ -0,0 +1,43 @@
+<?php
+
+declare(strict_types=1);
+
+namespace TypePHP\Tests\Fixtures\Pipes;
+
+class NativePipeRunner
+{
+    public function runPipeline(int $initialId, PipePipelineService $service): string
+    {
+        return $initialId
+            |> $service->doubleId(...)
+            |> $service->stringify(...)
+            |> $service->prefixTag(...);
+    }
+
+    public function runStandalonePipeline(int $id): string
+    {
+        return $id
+            |> $this->stepOne(...)
+            |> $this->stepTwo(...);
+    }
+
+    /**
+     * @param positive-int $id
+     *
+     * @return positive-int
+     */
+    public function stepOne(int $id): int
+    {
+        return $id + 10;
+    }
+
+    /**
+     * @param positive-int $id
+     *
+     * @return non-empty-string
+     */
+    public function stepTwo(int $id): string
+    {
+        return "piped_user_{$id}";
+    }
+}

tests/Fixtures/Pipes/PipePipelineService.php

@@ -0,0 +1,38 @@
+<?php
+
+declare(strict_types=1);
+
+namespace TypePHP\Tests\Fixtures\Pipes;
+
+class PipePipelineService
+{
+    /**
+     * @param positive-int $id
+     *
+     * @return positive-int
+     */
+    public function doubleId(int $id): int
+    {
+        return $id * 2;
+    }
+
+    /**
+     * @param positive-int $id
+     *
+     * @return non-empty-string
+     */
+    public function stringify(int $id): string
+    {
+        return "RECORD_{$id}";
+    }
+
+    /**
+     * @param non-empty-string $tag
+     *
+     * @return non-empty-string
+     */
+    public function prefixTag(string $tag): string
+    {
+        return "[TAG] {$tag}";
+    }
+}

tests/TypeChecking/Boundaries/PipeOperatorTest.php

@@ -0,0 +1,82 @@
+<?php
+
+declare(strict_types=1);
+
+if (PHP_VERSION_ID < 80500) {
+    return;
+}
+
+use TypePHP\Internal\StreamWrapper;
+use TypePHP\Tests\Fixtures\Pipes\NativePipeRunner;
+use TypePHP\Tests\Fixtures\Pipes\PipePipelineService;
+
+describe('PHP 8.5+ Pipe Operator (|>) and Multi-Step Pipelines', function () {
+    describe('Native Pipe Execution (PHP 8.5+)', function () {
+        test('executes multi-step piped transformation through first-class callables', function () {
+            $service = new PipePipelineService();
+            $runner = new NativePipeRunner();
+
+            $result = $runner->runPipeline(10, $service);
+
+            expect($result)->toBe('[TAG] RECORD_20');
+        });
+
+        test('throws TypeError at the exact pipe step where parameter contract is violated', function () {
+            $service = new PipePipelineService();
+            $runner = new NativePipeRunner();
+            
+            expect(fn () => $runner->runPipeline(-5, $service))
+                ->toThrow(TypeError::class, 'positive-int');
+        });
+
+        test('executes standalone method pipeline with native pipe operator', function () {
+            $runner = new NativePipeRunner();
+
+            $result = $runner->runStandalonePipeline(5);
+
+            expect($result)->toBe('piped_user_15');
+        });
+
+        test('throws TypeError when standalone pipe step receives invalid integer', function () {
+            $runner = new NativePipeRunner();
+
+            expect(fn () => $runner->runStandalonePipeline(-50))
+                ->toThrow(TypeError::class, 'positive-int');
+        });
+    });
+
+    describe('AST Transformation & Zero Line-Drift with Pipe Syntax', function () {
+        test('transforms code containing multi-line pipe operator chains with zero line-drift', function () {
+            $source = <<<'PHP'
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @param positive-int $id
+ * @return non-empty-string
+ */
+function formatId(int $id): string
+{
+    return "ID_{$id}";
+}
+
+$service = new \TypePHP\Tests\Fixtures\Pipes\PipePipelineService();
+
+$targetLine = true;
+PHP;
+
+            $transformed = StreamWrapper::transformSource($source, 'test_pipe_drift.php');
+
+            $origLines = explode("\n", str_replace("\r\n", "\n", $source));
+            $transLines = explode("\n", str_replace("\r\n", "\n", $transformed));
+
+            expect(count($transLines))->toBe(count($origLines));
+
+            $origTarget = array_search('$targetLine = true;', array_map('trim', $origLines), true);
+            $transTarget = array_search('$targetLine = true;', array_map('trim', $transLines), true);
+
+            expect($transTarget)->toBe($origTarget);
+        });
+    });
+});