Add tests for q-value parsing, 406, and Vary: Accept

tests/Feature/MarkdownOutputTest.php

@@ -48,3 +48,61 @@
         ->and($response['headers']['content-type'])
         ->toContain('text/markdown');
 });
+
+test('html is served when Accept prefers html over markdown via q-values', function () {
+    $response = makeRequest('/hello-world/', [
+        'Accept' => 'text/html, text/markdown;q=0.5',
+    ]);
+
+    expect($response['status'])->toBe(200)
+        ->and($response['headers']['content-type'])->toContain('text/html');
+});
+
+test('markdown is served when Accept prefers markdown over html via q-values', function () {
+    $response = makeRequest('/hello-world/', [
+        'Accept' => 'text/html;q=0.5, text/markdown;q=0.9',
+    ]);
+
+    expect($response['status'])->toBe(200)
+        ->and($response['headers']['content-type'])->toContain('text/markdown');
+});
+
+test('html is served when Accept is */* (default representation wins)', function () {
+    $response = makeRequest('/hello-world/', [
+        'Accept' => '*/*',
+    ]);
+
+    expect($response['headers']['content-type'])->toContain('text/html');
+});
+
+test('406 is returned when Accept rules out every supported representation', function () {
+    $response = makeRequest('/hello-world/', [
+        'Accept' => 'application/x-content-negotiation-probe',
+    ]);
+
+    expect($response['status'])->toBe(406);
+});
+
+test('406 is returned for application/json on a page that does not serve json', function () {
+    $response = makeRequest('/hello-world/', [
+        'Accept' => 'application/json',
+    ]);
+
+    expect($response['status'])->toBe(406);
+});
+
+test('html response advertises Vary: Accept for cache correctness', function () {
+    $response = makeRequest('/hello-world/');
+
+    expect($response['headers'])->toHaveKey('vary')
+        ->and($response['headers']['vary'])->toContain('Accept');
+});
+
+test('markdown response advertises Vary: Accept', function () {
+    $response = makeRequest('/hello-world/', [
+        'Accept' => 'text/markdown',
+    ]);
+
+    expect($response['headers'])->toHaveKey('vary')
+        ->and($response['headers']['vary'])->toContain('Accept');
+});

tests/Pest.php

@@ -22,19 +22,31 @@ function makeRequest(string $path, array $headers = []): array
     $context = stream_context_create($context_options);
     $response = @file_get_contents($url, false, $context);
 
-    // Parse response headers
+    // Parse status line and response headers. Repeated headers (e.g. Vary) are
+    // concatenated with ", " so assertions can inspect the combined value.
+    $status = 0;
     $responseHeaders = [];
     if (isset($http_response_header)) {
         foreach ($http_response_header as $header) {
+            if (preg_match('#^HTTP/\S+\s+(\d{3})#', $header, $m)) {
+                $status = (int) $m[1];
+
+                continue;
+            }
             if (str_contains($header, ':')) {
                 [$key, $value] = explode(':', $header, 2);
-                $responseHeaders[strtolower(trim($key))] = trim($value);
+                $key = strtolower(trim($key));
+                $value = trim($value);
+                $responseHeaders[$key] = isset($responseHeaders[$key])
+                    ? $responseHeaders[$key].', '.$value
+                    : $value;
             }
         }
     }
 
     return [
         'body' => $response !== false ? $response : '',
         'headers' => $responseHeaders,
+        'status' => $status,
     ];
 }