Inject commit-based image tags for Docker Compose build services

For Docker Compose applications with build directives, inject commit-based
image tags (uuid_servicename:commit) to enable rollback functionality.
Previously these services always used 'latest' tags, making rollback impossible.

- Only injects tags for services with build: but no explicit image:
- Uses pr-{id} tags for pull request deployments
- Respects user-defined image: fields (preserves user intent)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

tests/Unit/Parsers/ApplicationParserImageTagTest.php

@@ -0,0 +1,171 @@
+<?php
+
+/**
+ * Tests for Docker Compose image tag injection in applicationParser.
+ *
+ * These tests verify the logic for injecting commit-based image tags
+ * into Docker Compose services with build directives.
+ */
+it('injects image tag for services with build but no image directive', function () {
+    // Test the condition: hasBuild && !hasImage && commit
+    $service = [
+        'build' => './app',
+    ];
+
+    $hasBuild = data_get($service, 'build') !== null;
+    $hasImage = data_get($service, 'image') !== null;
+    $commit = 'abc123def456';
+    $uuid = 'app-uuid';
+    $serviceName = 'web';
+
+    expect($hasBuild)->toBeTrue();
+    expect($hasImage)->toBeFalse();
+
+    // Simulate the image injection logic
+    if ($hasBuild && ! $hasImage && $commit) {
+        $imageTag = str($commit)->substr(0, 128)->value();
+        $imageRepo = "{$uuid}_{$serviceName}";
+        $service['image'] = "{$imageRepo}:{$imageTag}";
+    }
+
+    expect($service['image'])->toBe('app-uuid_web:abc123def456');
+});
+
+it('does not inject image tag when service has explicit image directive', function () {
+    // User has specified their own image - we respect it
+    $service = [
+        'build' => './app',
+        'image' => 'myregistry/myapp:latest',
+    ];
+
+    $hasBuild = data_get($service, 'build') !== null;
+    $hasImage = data_get($service, 'image') !== null;
+    $commit = 'abc123def456';
+
+    expect($hasBuild)->toBeTrue();
+    expect($hasImage)->toBeTrue();
+
+    // The condition should NOT trigger
+    $shouldInject = $hasBuild && ! $hasImage && $commit;
+    expect($shouldInject)->toBeFalse();
+
+    // Image should remain unchanged
+    expect($service['image'])->toBe('myregistry/myapp:latest');
+});
+
+it('does not inject image tag when there is no commit', function () {
+    $service = [
+        'build' => './app',
+    ];
+
+    $hasBuild = data_get($service, 'build') !== null;
+    $hasImage = data_get($service, 'image') !== null;
+    $commit = null;
+
+    expect($hasBuild)->toBeTrue();
+    expect($hasImage)->toBeFalse();
+
+    // The condition should NOT trigger (no commit)
+    $shouldInject = $hasBuild && ! $hasImage && $commit;
+    expect($shouldInject)->toBeFalse();
+});
+
+it('does not inject image tag for services without build directive', function () {
+    // Service that pulls a pre-built image
+    $service = [
+        'image' => 'nginx:alpine',
+    ];
+
+    $hasBuild = data_get($service, 'build') !== null;
+    $hasImage = data_get($service, 'image') !== null;
+    $commit = 'abc123def456';
+
+    expect($hasBuild)->toBeFalse();
+    expect($hasImage)->toBeTrue();
+
+    // The condition should NOT trigger (no build)
+    $shouldInject = $hasBuild && ! $hasImage && $commit;
+    expect($shouldInject)->toBeFalse();
+});
+
+it('uses pr-{id} tag for pull request deployments', function () {
+    $service = [
+        'build' => './app',
+    ];
+
+    $hasBuild = data_get($service, 'build') !== null;
+    $hasImage = data_get($service, 'image') !== null;
+    $commit = 'abc123def456';
+    $uuid = 'app-uuid';
+    $serviceName = 'web';
+    $isPullRequest = true;
+    $pullRequestId = 42;
+
+    // Simulate the PR image injection logic
+    if ($hasBuild && ! $hasImage && $commit) {
+        $imageTag = str($commit)->substr(0, 128)->value();
+        if ($isPullRequest) {
+            $imageTag = "pr-{$pullRequestId}";
+        }
+        $imageRepo = "{$uuid}_{$serviceName}";
+        $service['image'] = "{$imageRepo}:{$imageTag}";
+    }
+
+    expect($service['image'])->toBe('app-uuid_web:pr-42');
+});
+
+it('truncates commit SHA to 128 characters', function () {
+    $service = [
+        'build' => './app',
+    ];
+
+    $hasBuild = data_get($service, 'build') !== null;
+    $hasImage = data_get($service, 'image') !== null;
+    // Create a very long commit string
+    $commit = str_repeat('a', 200);
+    $uuid = 'app-uuid';
+    $serviceName = 'web';
+
+    if ($hasBuild && ! $hasImage && $commit) {
+        $imageTag = str($commit)->substr(0, 128)->value();
+        $imageRepo = "{$uuid}_{$serviceName}";
+        $service['image'] = "{$imageRepo}:{$imageTag}";
+    }
+
+    // Tag should be exactly 128 characters
+    $parts = explode(':', $service['image']);
+    expect(strlen($parts[1]))->toBe(128);
+});
+
+it('handles multiple services with build directives', function () {
+    $services = [
+        'web' => ['build' => './web'],
+        'worker' => ['build' => './worker'],
+        'api' => ['build' => './api', 'image' => 'custom:tag'],  // Has explicit image
+        'redis' => ['image' => 'redis:alpine'],  // No build
+    ];
+
+    $commit = 'abc123';
+    $uuid = 'app-uuid';
+
+    foreach ($services as $serviceName => $service) {
+        $hasBuild = data_get($service, 'build') !== null;
+        $hasImage = data_get($service, 'image') !== null;
+
+        if ($hasBuild && ! $hasImage && $commit) {
+            $imageTag = str($commit)->substr(0, 128)->value();
+            $imageRepo = "{$uuid}_{$serviceName}";
+            $services[$serviceName]['image'] = "{$imageRepo}:{$imageTag}";
+        }
+    }
+
+    // web and worker should get injected images
+    expect($services['web']['image'])->toBe('app-uuid_web:abc123');
+    expect($services['worker']['image'])->toBe('app-uuid_worker:abc123');
+
+    // api keeps its custom image (has explicit image)
+    expect($services['api']['image'])->toBe('custom:tag');
+
+    // redis keeps its image (no build directive)
+    expect($services['redis']['image'])->toBe('redis:alpine');
+});