docs: fix typos and reformat tables in CLAUDE.md

Fix "Prever" typo, add Windows WSL test runner command, and align
Markdown table columns for readability.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

CLAUDE.md

@@ -76,15 +76,16 @@ Run vendor/bin/phpunit after each change to confirm tests stay green.
 
 **Common anti-patterns**
 
-| Wrong prompt | Why it breaks TDD | Correct prompt |
-|---|---|---|
-| "Write tests for this feature" | Claude implements first, then fits tests to it | "Write **failing** tests for [feature]. Stop before any implementation." |
-| "Add tests and implementation" | Loses the design feedback of failing tests | Two separate prompts: Red, then Green |
-| "Make the tests pass" | Encourages skipping to a green state | "Implement the minimum to make the failing tests pass." |
-| Combining Red + Green in one request | No failing baseline | Always separate the two phases |
+| Wrong prompt                         | Why it breaks TDD                              | Correct prompt                                                           |
+| ------------------------------------ | ---------------------------------------------- | ------------------------------------------------------------------------ |
+| "Write tests for this feature"       | Claude implements first, then fits tests to it | "Write **failing** tests for [feature]. Stop before any implementation." |
+| "Add tests and implementation"       | Loses the design feedback of failing tests     | Two separate prompts: Red, then Green                                    |
+| "Make the tests pass"                | Encourages skipping to a green state           | "Implement the minimum to make the failing tests pass."                  |
+| Combining Red + Green in one request | No failing baseline                            | Always separate the two phases                                           |
 
 ### Running tests
-Prever to use the tests in `docker compose exec graph`
+
+Prefer to use the tests in `docker compose exec graph`
 
 ```bash
 # Run full suite
@@ -100,6 +101,12 @@ vendor/bin/phpunit tests/Unit/Service/SvgRendererTest.php
 vendor/bin/phpunit --filter it_renders
 ```
 
+On Windows, run via WSL (If Docker Desctop is not):
+
+```powershell
+wsl -e bash -c "cd /mnt/g/_DEV/repos/git-contribution-graph && docker compose exec graph vendor/bin/phpunit --testdox 2>&1"
+```
+
 ### Auto-run hook
 
 Add to `.claude/settings.json` to run PHPUnit automatically after every file edit:
@@ -131,8 +138,8 @@ Workflow files live in [.gitea/workflows/](.gitea/workflows/). This project uses
 
 **Current workflows:**
 
-| File | Trigger | Purpose |
-|---|---|---|
+| File                 | Trigger          | Purpose                                                   |
+| -------------------- | ---------------- | --------------------------------------------------------- |
 | `docker-publish.yml` | Push tag `*.*.*` | Build & push multi-arch image to Gitea container registry |
 
 ## Docker
@@ -209,13 +216,13 @@ GET /graph.svg?theme=dark|light
 
 ## Environment variables
 
-| Variable | Required | Notes |
-|---|---|---|
-| `APP_SECRET` | Yes | 32+ char random string |
-| `GITHUB_USER` / `GITHUB_TOKEN` | For GitHub | Token scope: `read:user` |
-| `GITLAB_USER` / `GITLAB_TOKEN` | For GitLab | Token scopes: `read_user`, `read_api` |
-| `GITLAB_URL` | No | Defaults to `https://gitlab.com` |
-| `GITEA_USER` / `GITEA_TOKEN` / `GITEA_URL` | For Gitea | Token scope: `read:user` |
-| `ALLOWED_HOSTS` | No | Comma-separated hostnames; empty = allow all |
+| Variable                                   | Required   | Notes                                        |
+| ------------------------------------------ | ---------- | -------------------------------------------- |
+| `APP_SECRET`                               | Yes        | 32+ char random string                       |
+| `GITHUB_USER` / `GITHUB_TOKEN`             | For GitHub | Token scope: `read:user`                     |
+| `GITLAB_USER` / `GITLAB_TOKEN`             | For GitLab | Token scopes: `read_user`, `read_api`        |
+| `GITLAB_URL`                               | No         | Defaults to `https://gitlab.com`             |
+| `GITEA_USER` / `GITEA_TOKEN` / `GITEA_URL` | For Gitea  | Token scope: `read:user`                     |
+| `ALLOWED_HOSTS`                            | No         | Comma-separated hostnames; empty = allow all |
 
 Copy `.env` to `.env.local` for local development — `.env.local` is gitignored.

src/Controller/GraphController.php

@@ -1,8 +1,11 @@
 <?php
 
+declare(strict_types=1);
+
 namespace App\Controller;
 
 use App\Service\ContributionAggregator;
+use App\Service\ProviderHealthChecker;
 use App\Service\SvgRenderer;
 use Psr\Log\LoggerInterface;
 use Symfony\Component\DependencyInjection\Attribute\Autowire;
@@ -13,7 +16,7 @@ use Symfony\Component\Routing\Attribute\Route;
 use Symfony\Contracts\Cache\CacheInterface;
 use Symfony\Contracts\Cache\ItemInterface;
 
-class GraphController
+final class GraphController
 {
     /** @var list<string> */
     private readonly array $allowedHosts;
@@ -23,6 +26,7 @@ class GraphController
         private readonly SvgRenderer $renderer,
         private readonly CacheInterface $cache,
         private readonly LoggerInterface $logger,
+        private readonly ProviderHealthChecker $healthChecker,
         #[Autowire(env: 'ALLOWED_HOSTS')]
         string $allowedHosts = '',
     ) {
@@ -73,8 +77,13 @@ class GraphController
     #[Route('/health', name: 'health', methods: ['GET'])]
     public function health(): Response
     {
-        return new Response('{"status":"ok"}', 200, ['Content-Type' => 'application/json']);
+        $result     = $this->healthChecker->check();
+        $statusCode = $result['status'] === 'degraded' ? 503 : 200;
+
+        return new Response(
+            json_encode($result, JSON_PRETTY_PRINT | JSON_THROW_ON_ERROR),
+            $statusCode,
+            ['Content-Type' => 'application/json'],
+        );
     }
-
-
 }

src/Service/GitHubProvider.php

@@ -1,10 +1,13 @@
 <?php
 
+declare(strict_types=1);
+
 namespace App\Service;
 
 use IDCI\Bundle\GraphQLClientBundle\Client\GraphQLApiClient;
 use IDCI\Bundle\GraphQLClientBundle\Client\GraphQLApiClientRegistryInterface;
 use Psr\Log\LoggerInterface;
+use Symfony\Component\HttpKernel\Exception\ServiceUnavailableHttpException;
 use Symfony\Contracts\HttpClient\HttpClientInterface;
 
 /**
@@ -12,8 +15,10 @@ use Symfony\Contracts\HttpClient\HttpClientInterface;
  *
  * Required token scopes: read:user
  */
-class GitHubProvider implements ProviderInterface
+final class GitHubProvider implements ProviderInterface
 {
+    use ProbeTrait;
+
     private const GRAPHQL_URL = 'https://api.github.com/graphql';
 
     public function __construct(
@@ -24,11 +29,23 @@ class GitHubProvider implements ProviderInterface
         private readonly LoggerInterface $logger,
     ) {}
 
+    public function getName(): string
+    {
+        return 'github';
+    }
+
     public function isConfigured(): bool
     {
         return $this->username !== '' && $this->token !== '';
     }
 
+    public function ping(): void
+    {
+        $this->client->request('GET', 'https://api.github.com/user', [
+            'headers' => ['Authorization' => "Bearer {$this->token}"],
+        ])->getContent();
+    }
+
     /**
      * @return array<string, int>  date (Y-m-d) => contribution count
      */
@@ -69,7 +86,7 @@ class GitHubProvider implements ProviderInterface
         $data = $response->toArray();
 
         if (isset($data['errors'])) {
-            throw new \RuntimeException('GitHub GraphQL error: ' . json_encode($data['errors']));
+            throw new ServiceUnavailableHttpException(null, 'GitHub GraphQL error: ' . json_encode($data['errors']));
         }
 
         $result = [];

src/Service/GitLabProvider.php

@@ -1,8 +1,11 @@
 <?php
 
+declare(strict_types=1);
+
 namespace App\Service;
 
 use Psr\Log\LoggerInterface;
+use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
 use Symfony\Contracts\HttpClient\HttpClientInterface;
 
 /**
@@ -11,8 +14,10 @@ use Symfony\Contracts\HttpClient\HttpClientInterface;
  * Required token scopes: read_user, read_api
  * Works with both gitlab.com and self-hosted instances.
  */
-class GitLabProvider implements ProviderInterface
+final class GitLabProvider implements ProviderInterface
 {
+    use ProbeTrait;
+
     public function __construct(
         private readonly HttpClientInterface $client,
         private readonly string $username,
@@ -21,11 +26,25 @@ class GitLabProvider implements ProviderInterface
         private readonly string $baseUrl = '',
     ) {}
 
+    public function getName(): string
+    {
+        return 'gitlab';
+    }
+
     public function isConfigured(): bool
     {
         return $this->username !== '' && $this->token !== '';
     }
 
+    public function ping(): void
+    {
+        $baseUrl = rtrim($this->baseUrl !== '' ? $this->baseUrl : 'https://gitlab.com', '/');
+
+        $this->client->request('GET', "$baseUrl/api/v4/user", [
+            'headers' => ['PRIVATE-TOKEN' => $this->token],
+        ])->getContent();
+    }
+
     /**
      * @return array<string, int>  date (Y-m-d) => event count
      */
@@ -35,7 +54,6 @@ class GitLabProvider implements ProviderInterface
 
         $this->logger->debug('GitLabProvider: fetching contributions', ['user' => $this->username, 'url' => $baseUrl]);
 
-        // Resolve numeric user ID from username
         $userResponse = $this->client->request('GET', "$baseUrl/api/v4/users", [
             'headers' => ['PRIVATE-TOKEN' => $this->token],
             'query'   => ['username' => $this->username],
@@ -43,7 +61,7 @@ class GitLabProvider implements ProviderInterface
 
         $users = $userResponse->toArray();
         if (empty($users)) {
-            throw new \RuntimeException("GitLab: user '{$this->username}' not found on $baseUrl");
+            throw new NotFoundHttpException("GitLab: user '{$this->username}' not found on $baseUrl");
         }
         $userId = $users[0]['id'];
 

src/Service/GiteaProvider.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace App\Service;
 
 use Psr\Log\LoggerInterface;
@@ -13,8 +15,10 @@ use Symfony\Contracts\HttpClient\HttpClientInterface;
  *
  * Required token scopes: read:user
  */
-class GiteaProvider implements ProviderInterface
+final class GiteaProvider implements ProviderInterface
 {
+    use ProbeTrait;
+
     public function __construct(
         private readonly HttpClientInterface $client,
         private readonly string $username,
@@ -23,17 +27,31 @@ class GiteaProvider implements ProviderInterface
         private readonly LoggerInterface $logger,
     ) {}
 
+    public function getName(): string
+    {
+        return 'gitea';
+    }
+
     public function isConfigured(): bool
     {
         return $this->username !== '' && $this->token !== '' && $this->baseUrl !== '';
     }
 
+    public function ping(): void
+    {
+        $baseUrl = rtrim($this->baseUrl, '/');
+
+        $this->client->request('GET', "$baseUrl/api/v1/user", [
+            'headers' => ['Authorization' => "token {$this->token}"],
+        ])->getContent();
+    }
+
     /**
      * @return array<string, int>  date (Y-m-d) => contribution count
      */
     public function fetch(): array
     {
-        $baseUrl  = rtrim($this->baseUrl, '/');
+        $baseUrl = rtrim($this->baseUrl, '/');
 
         $this->logger->debug('GiteaProvider: fetching contributions', ['user' => $this->username, 'url' => $baseUrl]);
 

src/Service/ProbeTrait.php

@@ -0,0 +1,63 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Service;
+
+use Symfony\Contracts\HttpClient\Exception\HttpExceptionInterface;
+use Symfony\Contracts\HttpClient\Exception\TransportExceptionInterface;
+
+trait ProbeTrait
+{
+    public function probe(): ProviderStatus
+    {
+        if (!$this->isConfigured()) {
+            return new ProviderStatus($this->getName(), ProviderStatusType::NotConfigured);
+        }
+
+        try {
+            $this->ping();
+
+            return new ProviderStatus($this->getName(), ProviderStatusType::Ok);
+        } catch (\Throwable $e) {
+            return $this->statusFromException($e);
+        }
+    }
+
+    private function statusFromException(\Throwable $e): ProviderStatus
+    {
+        [$error, $message] = $this->classifyException($e);
+
+        return new ProviderStatus($this->getName(), ProviderStatusType::Error, $error, $message);
+    }
+
+    /** @return array{ProviderErrorCode, string} */
+    private function classifyException(\Throwable $e): array
+    {
+        if ($e instanceof TransportExceptionInterface) {
+            return [ProviderErrorCode::UrlUnreachable, 'Could not reach the server: ' . $e->getMessage()];
+        }
+
+        if ($e instanceof HttpExceptionInterface) {
+            $code = $e->getResponse()->getStatusCode();
+
+            return match (true) {
+                $code === 401 => [ProviderErrorCode::AuthFailed, 'Invalid or expired token — verify your credentials'],
+                $code === 403 => [ProviderErrorCode::AuthFailed, 'Access denied — token lacks the required scopes'],
+                $code === 404 => [ProviderErrorCode::UrlUnreachable, 'Endpoint not found — check the configured URL'],
+                default       => [ProviderErrorCode::Unknown, "HTTP {$code}: " . $e->getMessage()],
+            };
+        }
+
+        $msg   = $e->getMessage();
+        $lower = strtolower($msg);
+        $error = match (true) {
+            str_contains($msg, 'not found') || str_contains($msg, 'Could not resolve') => ProviderErrorCode::UserNotFound,
+            str_contains($msg, 'GraphQL error')
+                && (str_contains($lower, 'unauthorized') || str_contains($lower, 'bad credentials')) => ProviderErrorCode::AuthFailed,
+            default => ProviderErrorCode::Unknown,
+        };
+
+        return [$error, $msg];
+    }
+}

src/Service/ProviderErrorCode.php

@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Service;
+
+enum ProviderErrorCode: string
+{
+    case AuthFailed     = 'auth_failed';
+    case UrlUnreachable = 'url_unreachable';
+    case UserNotFound   = 'user_not_found';
+    case Unknown        = 'unknown';
+}

src/Service/ProviderHealthChecker.php

@@ -0,0 +1,39 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Service;
+
+use Symfony\Component\DependencyInjection\Attribute\AutowireIterator;
+
+final class ProviderHealthChecker
+{
+    public function __construct(
+        #[AutowireIterator('app.provider')]
+        private readonly iterable $providers,
+    ) {}
+
+    /**
+     * @return array{status: string, providers: array<string, array<string, string>>}
+     */
+    public function check(): array
+    {
+        $statuses = [];
+        $hasError = false;
+
+        /** @var ProviderInterface $provider */
+        foreach ($this->providers as $provider) {
+            $status                  = $provider->probe();
+            $statuses[$status->name] = $status->toArray();
+
+            if ($status->status === ProviderStatusType::Error) {
+                $hasError = true;
+            }
+        }
+
+        return [
+            'status'    => $hasError ? 'degraded' : 'ok',
+            'providers' => $statuses,
+        ];
+    }
+}

src/Service/ProviderInterface.php

@@ -10,4 +10,10 @@ interface ProviderInterface
     public function fetch(): array;
 
     public function isConfigured(): bool;
+
+    public function getName(): string;
+
+    public function probe(): ProviderStatus;
+
+    public function ping(): void;
 }

src/Service/ProviderStatus.php

@@ -0,0 +1,29 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Service;
+
+final class ProviderStatus
+{
+    public function __construct(
+        public readonly string $name,
+        public readonly ProviderStatusType $status,
+        public readonly ?ProviderErrorCode $error = null,
+        public readonly ?string $message = null,
+    ) {}
+
+    /** @return array<string, string> */
+    public function toArray(): array
+    {
+        $data = ['status' => $this->status->value];
+        if ($this->error !== null) {
+            $data['error'] = $this->error->value;
+        }
+        if ($this->message !== null) {
+            $data['message'] = $this->message;
+        }
+
+        return $data;
+    }
+}

src/Service/ProviderStatusType.php

@@ -0,0 +1,12 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Service;
+
+enum ProviderStatusType: string
+{
+    case Ok            = 'ok';
+    case Error         = 'error';
+    case NotConfigured = 'not_configured';
+}

src/Service/SvgRenderer.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace App\Service;
 
 /**
@@ -11,7 +13,7 @@ namespace App\Service;
  *  - Month labels above, weekday labels (Mon/Wed/Fri) on the left
  *  - 5 intensity levels (0–4) matched to GitHub's colour palette
  */
-class SvgRenderer
+final class SvgRenderer
 {
     // GitHub's exact colour tokens
     private const THEMES = [

tests/Unit/Service/ContributionAggregatorTest.php

@@ -0,0 +1,109 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Unit\Service;
+
+use App\Service\ContributionAggregator;
+use App\Service\ProviderInterface;
+use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\Attributes\Test;
+use PHPUnit\Framework\TestCase;
+use Psr\Log\LoggerInterface;
+
+#[CoversClass(ContributionAggregator::class)]
+final class ContributionAggregatorTest extends TestCase
+{
+    private LoggerInterface $logger;
+
+    protected function setUp(): void
+    {
+        $this->logger = $this->createStub(LoggerInterface::class);
+    }
+
+    #[Test]
+    public function it_returns_empty_array_when_no_providers_are_given(): void
+    {
+        $aggregator = new ContributionAggregator([], $this->logger);
+
+        $result = $aggregator->aggregate();
+
+        $this->assertSame([], $result);
+    }
+
+    #[Test]
+    public function it_skips_unconfigured_providers(): void
+    {
+        $provider = $this->createStub(ProviderInterface::class);
+        $provider->method('isConfigured')->willReturn(false);
+
+        $aggregator = new ContributionAggregator([$provider], $this->logger);
+
+        $result = $aggregator->aggregate();
+
+        $this->assertSame([], $result);
+    }
+
+    #[Test]
+    public function it_returns_contributions_from_a_configured_provider(): void
+    {
+        $provider = $this->createStub(ProviderInterface::class);
+        $provider->method('isConfigured')->willReturn(true);
+        $provider->method('fetch')->willReturn(['2024-01-01' => 3]);
+
+        $aggregator = new ContributionAggregator([$provider], $this->logger);
+
+        $result = $aggregator->aggregate();
+
+        $this->assertSame(['2024-01-01' => 3], $result);
+    }
+
+    #[Test]
+    public function it_sums_contributions_from_multiple_providers_on_the_same_date(): void
+    {
+        $providerA = $this->createStub(ProviderInterface::class);
+        $providerA->method('isConfigured')->willReturn(true);
+        $providerA->method('fetch')->willReturn(['2024-01-01' => 3, '2024-01-02' => 1]);
+
+        $providerB = $this->createStub(ProviderInterface::class);
+        $providerB->method('isConfigured')->willReturn(true);
+        $providerB->method('fetch')->willReturn(['2024-01-01' => 2, '2024-01-03' => 5]);
+
+        $aggregator = new ContributionAggregator([$providerA, $providerB], $this->logger);
+
+        $result = $aggregator->aggregate();
+
+        $this->assertSame(['2024-01-01' => 5, '2024-01-02' => 1, '2024-01-03' => 5], $result);
+    }
+
+    #[Test]
+    public function it_continues_fetching_remaining_providers_when_one_throws(): void
+    {
+        $failing = $this->createStub(ProviderInterface::class);
+        $failing->method('isConfigured')->willReturn(true);
+        $failing->method('fetch')->willThrowException(new \RuntimeException('Network error'));
+
+        $healthy = $this->createStub(ProviderInterface::class);
+        $healthy->method('isConfigured')->willReturn(true);
+        $healthy->method('fetch')->willReturn(['2024-01-01' => 7]);
+
+        $aggregator = new ContributionAggregator([$failing, $healthy], $this->logger);
+
+        $result = $aggregator->aggregate();
+
+        $this->assertSame(['2024-01-01' => 7], $result);
+    }
+
+    #[Test]
+    public function it_logs_a_warning_when_a_provider_fetch_throws(): void
+    {
+        $logger = $this->createMock(LoggerInterface::class);
+        $logger->expects($this->once())->method('warning');
+
+        $provider = $this->createStub(ProviderInterface::class);
+        $provider->method('isConfigured')->willReturn(true);
+        $provider->method('fetch')->willThrowException(new \RuntimeException('fail'));
+
+        (new ContributionAggregator([$provider], $logger))->aggregate();
+    }
+}

tests/Unit/Service/GitHubProviderTest.php

@@ -0,0 +1,146 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Unit\Service;
+
+use App\Service\GitHubProvider;
+use IDCI\Bundle\GraphQLClientBundle\Client\GraphQLApiClient;
+use IDCI\Bundle\GraphQLClientBundle\Client\GraphQLApiClientRegistryInterface;
+use IDCI\Bundle\GraphQLClientBundle\Query\GraphQLQuery;
+use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\Attributes\Test;
+use PHPUnit\Framework\TestCase;
+use Psr\Log\LoggerInterface;
+use Symfony\Component\HttpKernel\Exception\ServiceUnavailableHttpException;
+use Symfony\Contracts\HttpClient\HttpClientInterface;
+use Symfony\Contracts\HttpClient\ResponseInterface;
+
+#[CoversClass(GitHubProvider::class)]
+final class GitHubProviderTest extends TestCase
+{
+    private function makeProvider(
+        string $username = 'user',
+        string $token = 'token',
+        ?HttpClientInterface $client = null,
+        ?GraphQLApiClientRegistryInterface $registry = null,
+    ): GitHubProvider {
+        if ($registry === null) {
+            $graphqlQuery = $this->createStub(GraphQLQuery::class);
+            $graphqlQuery->method('getGraphQLQuery')->willReturn('query {}');
+
+            $graphqlClient = $this->createStub(GraphQLApiClient::class);
+            $graphqlClient->method('buildQuery')->willReturn($graphqlQuery);
+
+            $registry = $this->createStub(GraphQLApiClientRegistryInterface::class);
+            $registry->method('get')->willReturn($graphqlClient);
+        }
+
+        return new GitHubProvider(
+            $client ?? $this->createStub(HttpClientInterface::class),
+            $registry,
+            $username,
+            $token,
+            $this->createStub(LoggerInterface::class),
+        );
+    }
+
+    private function stubGraphqlResponse(array $weeks): ResponseInterface
+    {
+        $response = $this->createStub(ResponseInterface::class);
+        $response->method('toArray')->willReturn([
+            'data' => [
+                'user' => [
+                    'contributionsCollection' => [
+                        'contributionCalendar' => ['weeks' => $weeks],
+                    ],
+                ],
+            ],
+        ]);
+
+        return $response;
+    }
+
+    #[Test]
+    public function it_returns_github_as_name(): void
+    {
+        $this->assertSame('github', $this->makeProvider()->getName());
+    }
+
+    #[Test]
+    public function it_is_configured_when_credentials_are_set(): void
+    {
+        $this->assertTrue($this->makeProvider()->isConfigured());
+    }
+
+    #[Test]
+    public function it_is_not_configured_when_username_is_empty(): void
+    {
+        $this->assertFalse($this->makeProvider(username: '')->isConfigured());
+    }
+
+    #[Test]
+    public function it_is_not_configured_when_token_is_empty(): void
+    {
+        $this->assertFalse($this->makeProvider(token: '')->isConfigured());
+    }
+
+    #[Test]
+    public function it_parses_contribution_days_from_the_graphql_response(): void
+    {
+        $client = $this->createStub(HttpClientInterface::class);
+        $client->method('request')->willReturn($this->stubGraphqlResponse([
+            ['contributionDays' => [
+                ['date' => '2024-06-10', 'contributionCount' => 4],
+                ['date' => '2024-06-11', 'contributionCount' => 2],
+            ]],
+        ]));
+
+        $result = $this->makeProvider(client: $client)->fetch();
+
+        $this->assertSame(4, $result['2024-06-10']);
+        $this->assertSame(2, $result['2024-06-11']);
+    }
+
+    #[Test]
+    public function it_skips_days_with_zero_contributions(): void
+    {
+        $client = $this->createStub(HttpClientInterface::class);
+        $client->method('request')->willReturn($this->stubGraphqlResponse([
+            ['contributionDays' => [
+                ['date' => '2024-06-11', 'contributionCount' => 0],
+            ]],
+        ]));
+
+        $result = $this->makeProvider(client: $client)->fetch();
+
+        $this->assertArrayNotHasKey('2024-06-11', $result);
+    }
+
+    #[Test]
+    public function it_throws_service_unavailable_exception_on_graphql_errors(): void
+    {
+        $response = $this->createStub(ResponseInterface::class);
+        $response->method('toArray')->willReturn([
+            'errors' => [['message' => 'Bad credentials']],
+        ]);
+
+        $client = $this->createStub(HttpClientInterface::class);
+        $client->method('request')->willReturn($response);
+
+        $this->expectException(ServiceUnavailableHttpException::class);
+
+        $this->makeProvider(client: $client)->fetch();
+    }
+
+    #[Test]
+    public function it_returns_empty_when_response_has_no_weeks(): void
+    {
+        $client = $this->createStub(HttpClientInterface::class);
+        $client->method('request')->willReturn($this->stubGraphqlResponse([]));
+
+        $result = $this->makeProvider(client: $client)->fetch();
+
+        $this->assertSame([], $result);
+    }
+}

tests/Unit/Service/GitLabProviderTest.php

@@ -0,0 +1,128 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Unit\Service;
+
+use App\Service\GitLabProvider;
+use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\Attributes\Test;
+use PHPUnit\Framework\TestCase;
+use Psr\Log\LoggerInterface;
+use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
+use Symfony\Contracts\HttpClient\HttpClientInterface;
+use Symfony\Contracts\HttpClient\ResponseInterface;
+
+#[CoversClass(GitLabProvider::class)]
+final class GitLabProviderTest extends TestCase
+{
+    private function makeProvider(
+        string $username = 'user',
+        string $token = 'token',
+        string $baseUrl = '',
+        ?HttpClientInterface $client = null,
+    ): GitLabProvider {
+        return new GitLabProvider(
+            $client ?? $this->createStub(HttpClientInterface::class),
+            $username,
+            $token,
+            $this->createStub(LoggerInterface::class),
+            $baseUrl,
+        );
+    }
+
+    private function stubResponse(array $data): ResponseInterface
+    {
+        $response = $this->createStub(ResponseInterface::class);
+        $response->method('toArray')->willReturn($data);
+
+        return $response;
+    }
+
+    #[Test]
+    public function it_returns_gitlab_as_name(): void
+    {
+        $this->assertSame('gitlab', $this->makeProvider()->getName());
+    }
+
+    #[Test]
+    public function it_is_configured_when_credentials_are_set(): void
+    {
+        $this->assertTrue($this->makeProvider()->isConfigured());
+    }
+
+    #[Test]
+    public function it_is_not_configured_when_username_is_empty(): void
+    {
+        $this->assertFalse($this->makeProvider(username: '')->isConfigured());
+    }
+
+    #[Test]
+    public function it_is_not_configured_when_token_is_empty(): void
+    {
+        $this->assertFalse($this->makeProvider(token: '')->isConfigured());
+    }
+
+    #[Test]
+    public function it_throws_not_found_exception_when_user_does_not_exist(): void
+    {
+        $client = $this->createStub(HttpClientInterface::class);
+        $client->method('request')->willReturn($this->stubResponse([]));
+
+        $this->expectException(NotFoundHttpException::class);
+
+        $this->makeProvider(client: $client)->fetch();
+    }
+
+    #[Test]
+    public function it_fetches_events_and_counts_them_by_date(): void
+    {
+        $client = $this->createMock(HttpClientInterface::class);
+        $client->method('request')->willReturnCallback(
+            function (string $method, string $url): ResponseInterface {
+                if (str_contains($url, '/events')) {
+                    return $this->stubResponse([
+                        ['created_at' => '2024-06-10T12:00:00.000Z'],
+                        ['created_at' => '2024-06-10T14:00:00.000Z'],
+                        ['created_at' => '2024-06-11T08:00:00.000Z'],
+                    ]);
+                }
+
+                return $this->stubResponse([['id' => 42]]);
+            }
+        );
+
+        $result = $this->makeProvider(client: $client)->fetch();
+
+        $this->assertSame(2, $result['2024-06-10']);
+        $this->assertSame(1, $result['2024-06-11']);
+    }
+
+    #[Test]
+    public function it_fetches_multiple_pages_until_page_has_fewer_than_100_events(): void
+    {
+        $callCount = 0;
+
+        $client = $this->createMock(HttpClientInterface::class);
+        $client->method('request')->willReturnCallback(
+            function (string $method, string $url) use (&$callCount): ResponseInterface {
+                if (!str_contains($url, '/events')) {
+                    return $this->stubResponse([['id' => 42]]);
+                }
+
+                $callCount++;
+                $data = $callCount === 1
+                    ? array_fill(0, 100, ['created_at' => '2024-06-10T12:00:00.000Z'])
+                    : [['created_at' => '2024-06-11T08:00:00.000Z']];
+
+                return $this->stubResponse($data);
+            }
+        );
+
+        $result = $this->makeProvider(client: $client)->fetch();
+
+        $this->assertSame(2, $callCount);
+        $this->assertSame(100, $result['2024-06-10']);
+        $this->assertSame(1, $result['2024-06-11']);
+    }
+}

tests/Unit/Service/GiteaProviderTest.php

@@ -0,0 +1,111 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Unit\Service;
+
+use App\Service\GiteaProvider;
+use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\Attributes\Test;
+use PHPUnit\Framework\TestCase;
+use Psr\Log\LoggerInterface;
+use Symfony\Contracts\HttpClient\HttpClientInterface;
+use Symfony\Contracts\HttpClient\ResponseInterface;
+
+#[CoversClass(GiteaProvider::class)]
+final class GiteaProviderTest extends TestCase
+{
+    private function makeProvider(
+        string $username = 'user',
+        string $token = 'token',
+        string $baseUrl = 'https://gitea.example.com',
+        ?HttpClientInterface $client = null,
+    ): GiteaProvider {
+        return new GiteaProvider(
+            $client ?? $this->createStub(HttpClientInterface::class),
+            $username,
+            $token,
+            $baseUrl,
+            $this->createStub(LoggerInterface::class),
+        );
+    }
+
+    private function stubResponse(array $data): ResponseInterface
+    {
+        $response = $this->createStub(ResponseInterface::class);
+        $response->method('toArray')->willReturn($data);
+
+        return $response;
+    }
+
+    #[Test]
+    public function it_returns_gitea_as_name(): void
+    {
+        $this->assertSame('gitea', $this->makeProvider()->getName());
+    }
+
+    #[Test]
+    public function it_is_configured_when_all_credentials_are_set(): void
+    {
+        $this->assertTrue($this->makeProvider()->isConfigured());
+    }
+
+    #[Test]
+    public function it_is_not_configured_when_username_is_empty(): void
+    {
+        $this->assertFalse($this->makeProvider(username: '')->isConfigured());
+    }
+
+    #[Test]
+    public function it_is_not_configured_when_token_is_empty(): void
+    {
+        $this->assertFalse($this->makeProvider(token: '')->isConfigured());
+    }
+
+    #[Test]
+    public function it_is_not_configured_when_base_url_is_empty(): void
+    {
+        $this->assertFalse($this->makeProvider(baseUrl: '')->isConfigured());
+    }
+
+    #[Test]
+    public function it_parses_heatmap_entries_into_contributions(): void
+    {
+        $now = time();
+
+        $client = $this->createStub(HttpClientInterface::class);
+        $client->method('request')->willReturn($this->stubResponse([
+            ['timestamp' => $now, 'contributions' => 5],
+        ]));
+
+        $result = $this->makeProvider(client: $client)->fetch();
+
+        $this->assertSame(5, $result[date('Y-m-d', $now)]);
+    }
+
+    #[Test]
+    public function it_filters_out_entries_older_than_365_days(): void
+    {
+        $old = (new \DateTimeImmutable('-366 days'))->getTimestamp();
+
+        $client = $this->createStub(HttpClientInterface::class);
+        $client->method('request')->willReturn($this->stubResponse([
+            ['timestamp' => $old, 'contributions' => 3],
+        ]));
+
+        $result = $this->makeProvider(client: $client)->fetch();
+
+        $this->assertSame([], $result);
+    }
+
+    #[Test]
+    public function it_returns_empty_when_response_has_no_entries(): void
+    {
+        $client = $this->createStub(HttpClientInterface::class);
+        $client->method('request')->willReturn($this->stubResponse([]));
+
+        $result = $this->makeProvider(client: $client)->fetch();
+
+        $this->assertSame([], $result);
+    }
+}

tests/Unit/Service/ProbeTraitTest.php

@@ -0,0 +1,128 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Unit\Service;
+
+use App\Service\ProbeTrait;
+use App\Service\ProviderErrorCode;
+use App\Service\ProviderInterface;
+use App\Service\ProviderStatusType;
+use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\Attributes\Test;
+use PHPUnit\Framework\TestCase;
+use Symfony\Contracts\HttpClient\Exception\ClientExceptionInterface;
+use Symfony\Contracts\HttpClient\Exception\TransportExceptionInterface;
+use Symfony\Contracts\HttpClient\ResponseInterface;
+
+#[CoversClass(ProbeTrait::class)]
+final class ProbeTraitTest extends TestCase
+{
+    private function makeProvider(bool $configured, \Closure $ping): ProviderInterface
+    {
+        return new class($configured, $ping) implements ProviderInterface {
+            use ProbeTrait;
+
+            public function __construct(
+                private bool $configured,
+                private \Closure $ping,
+            ) {}
+
+            public function isConfigured(): bool { return $this->configured; }
+            public function getName(): string { return 'test'; }
+            public function ping(): void { ($this->ping)(); }
+            public function fetch(): array { return []; }
+        };
+    }
+
+    #[Test]
+    public function it_returns_not_configured_when_provider_is_not_configured(): void
+    {
+        $provider = $this->makeProvider(false, fn() => null);
+
+        $status = $provider->probe();
+
+        $this->assertSame(ProviderStatusType::NotConfigured, $status->status);
+        $this->assertNull($status->error);
+    }
+
+    #[Test]
+    public function it_returns_ok_when_ping_succeeds(): void
+    {
+        $provider = $this->makeProvider(true, fn() => null);
+
+        $status = $provider->probe();
+
+        $this->assertSame(ProviderStatusType::Ok, $status->status);
+        $this->assertNull($status->error);
+    }
+
+    #[Test]
+    public function it_returns_url_unreachable_on_transport_failure(): void
+    {
+        $exception = $this->createStub(TransportExceptionInterface::class);
+        $provider  = $this->makeProvider(true, fn() => throw $exception);
+
+        $status = $provider->probe();
+
+        $this->assertSame(ProviderStatusType::Error, $status->status);
+        $this->assertSame(ProviderErrorCode::UrlUnreachable, $status->error);
+    }
+
+    #[Test]
+    public function it_returns_auth_failed_on_401(): void
+    {
+        $response = $this->createStub(ResponseInterface::class);
+        $response->method('getStatusCode')->willReturn(401);
+
+        $exception = $this->createStub(ClientExceptionInterface::class);
+        $exception->method('getResponse')->willReturn($response);
+
+        $status = $this->makeProvider(true, fn() => throw $exception)->probe();
+
+        $this->assertSame(ProviderStatusType::Error, $status->status);
+        $this->assertSame(ProviderErrorCode::AuthFailed, $status->error);
+    }
+
+    #[Test]
+    public function it_returns_auth_failed_on_403(): void
+    {
+        $response = $this->createStub(ResponseInterface::class);
+        $response->method('getStatusCode')->willReturn(403);
+
+        $exception = $this->createStub(ClientExceptionInterface::class);
+        $exception->method('getResponse')->willReturn($response);
+
+        $status = $this->makeProvider(true, fn() => throw $exception)->probe();
+
+        $this->assertSame(ProviderStatusType::Error, $status->status);
+        $this->assertSame(ProviderErrorCode::AuthFailed, $status->error);
+    }
+
+    #[Test]
+    public function it_returns_url_unreachable_on_404(): void
+    {
+        $response = $this->createStub(ResponseInterface::class);
+        $response->method('getStatusCode')->willReturn(404);
+
+        $exception = $this->createStub(ClientExceptionInterface::class);
+        $exception->method('getResponse')->willReturn($response);
+
+        $status = $this->makeProvider(true, fn() => throw $exception)->probe();
+
+        $this->assertSame(ProviderStatusType::Error, $status->status);
+        $this->assertSame(ProviderErrorCode::UrlUnreachable, $status->error);
+    }
+
+    #[Test]
+    public function it_returns_unknown_error_on_unexpected_exception(): void
+    {
+        $provider = $this->makeProvider(true, fn() => throw new \RuntimeException('Something went wrong'));
+
+        $status = $provider->probe();
+
+        $this->assertSame(ProviderStatusType::Error, $status->status);
+        $this->assertSame(ProviderErrorCode::Unknown, $status->error);
+        $this->assertSame('Something went wrong', $status->message);
+    }
+}

tests/Unit/Service/ProviderHealthCheckerTest.php

@@ -0,0 +1,88 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Unit\Service;
+
+use App\Service\ProviderErrorCode;
+use App\Service\ProviderHealthChecker;
+use App\Service\ProviderInterface;
+use App\Service\ProviderStatus;
+use App\Service\ProviderStatusType;
+use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\Attributes\Test;
+use PHPUnit\Framework\TestCase;
+
+#[CoversClass(ProviderHealthChecker::class)]
+final class ProviderHealthCheckerTest extends TestCase
+{
+    #[Test]
+    public function it_returns_ok_when_all_providers_are_healthy(): void
+    {
+        $provider = $this->createStub(ProviderInterface::class);
+        $provider->method('probe')->willReturn(new ProviderStatus('test', ProviderStatusType::Ok));
+
+        $result = (new ProviderHealthChecker([$provider]))->check();
+
+        $this->assertSame('ok', $result['status']);
+    }
+
+    #[Test]
+    public function it_returns_degraded_when_a_provider_has_an_error(): void
+    {
+        $provider = $this->createStub(ProviderInterface::class);
+        $provider->method('probe')->willReturn(
+            new ProviderStatus('test', ProviderStatusType::Error, ProviderErrorCode::AuthFailed, 'Invalid token'),
+        );
+
+        $result = (new ProviderHealthChecker([$provider]))->check();
+
+        $this->assertSame('degraded', $result['status']);
+    }
+
+    #[Test]
+    public function it_does_not_degrade_when_a_provider_is_not_configured(): void
+    {
+        $provider = $this->createStub(ProviderInterface::class);
+        $provider->method('probe')->willReturn(new ProviderStatus('test', ProviderStatusType::NotConfigured));
+
+        $result = (new ProviderHealthChecker([$provider]))->check();
+
+        $this->assertSame('ok', $result['status']);
+    }
+
+    #[Test]
+    public function it_indexes_provider_statuses_by_name(): void
+    {
+        $provider = $this->createStub(ProviderInterface::class);
+        $provider->method('probe')->willReturn(new ProviderStatus('github', ProviderStatusType::Ok));
+
+        $result = (new ProviderHealthChecker([$provider]))->check();
+
+        $this->assertArrayHasKey('github', $result['providers']);
+    }
+
+    #[Test]
+    public function it_returns_ok_with_no_providers(): void
+    {
+        $result = (new ProviderHealthChecker([]))->check();
+
+        $this->assertSame('ok', $result['status']);
+        $this->assertSame([], $result['providers']);
+    }
+
+    #[Test]
+    public function it_includes_all_provider_statuses_in_output(): void
+    {
+        $github = $this->createStub(ProviderInterface::class);
+        $github->method('probe')->willReturn(new ProviderStatus('github', ProviderStatusType::Ok));
+
+        $gitlab = $this->createStub(ProviderInterface::class);
+        $gitlab->method('probe')->willReturn(new ProviderStatus('gitlab', ProviderStatusType::NotConfigured));
+
+        $result = (new ProviderHealthChecker([$github, $gitlab]))->check();
+
+        $this->assertArrayHasKey('github', $result['providers']);
+        $this->assertArrayHasKey('gitlab', $result['providers']);
+    }
+}

tests/Unit/Service/ProviderStatusTest.php

@@ -0,0 +1,64 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Unit\Service;
+
+use App\Service\ProviderErrorCode;
+use App\Service\ProviderStatus;
+use App\Service\ProviderStatusType;
+use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\Attributes\Test;
+use PHPUnit\Framework\TestCase;
+
+#[CoversClass(ProviderStatus::class)]
+final class ProviderStatusTest extends TestCase
+{
+    #[Test]
+    public function it_serializes_ok_status(): void
+    {
+        $status = new ProviderStatus('github', ProviderStatusType::Ok);
+
+        $this->assertSame(['status' => 'ok'], $status->toArray());
+    }
+
+    #[Test]
+    public function it_serializes_not_configured_status(): void
+    {
+        $status = new ProviderStatus('github', ProviderStatusType::NotConfigured);
+
+        $this->assertSame(['status' => 'not_configured'], $status->toArray());
+    }
+
+    #[Test]
+    public function it_serializes_error_status_with_code_and_message(): void
+    {
+        $status = new ProviderStatus('github', ProviderStatusType::Error, ProviderErrorCode::AuthFailed, 'Token expired');
+
+        $this->assertSame([
+            'status'  => 'error',
+            'error'   => 'auth_failed',
+            'message' => 'Token expired',
+        ], $status->toArray());
+    }
+
+    #[Test]
+    public function it_omits_null_error_fields_from_array(): void
+    {
+        $status = new ProviderStatus('github', ProviderStatusType::Ok);
+
+        $array = $status->toArray();
+
+        $this->assertArrayNotHasKey('error', $array);
+        $this->assertArrayNotHasKey('message', $array);
+    }
+
+    #[Test]
+    public function it_exposes_typed_status_property(): void
+    {
+        $status = new ProviderStatus('github', ProviderStatusType::Error, ProviderErrorCode::Unknown, 'msg');
+
+        $this->assertSame(ProviderStatusType::Error, $status->status);
+        $this->assertSame(ProviderErrorCode::Unknown, $status->error);
+    }
+}