feature symfony#61267 [HttpFoundation] Add support for structured MIME suffix (Spomky)

This PR was merged into the 7.4 branch.

Discussion
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[HttpFoundation] Add support for structured MIME suffix

| Q             | A
| ------------- | ---
| Branch?       | 7.4
| Bug fix?      | no
| New feature?  | yes
| Deprecations? | no
| Issues        | Fix symfony#61213
| License       | MIT

Extended MIME type handling in `Request::getFormat()` to support structured suffixes like `application/soap+xml`. Introduced a private method to define fallback formats based on RFC specifications. Updated the test suite accordingly.
It adds supports for common mime types:

* `soap`: application/soap+xml (instead of `xml`)
* `problem`: application/problem+json
* `hal`: application/hal+json, application/hal+xml
* `jsonapi`: application/vnd.api+json
* `yaml`: text/yaml, application/x-yaml
* `wbxml`: application/vnd.wap.wbxml
* `pdf`: application/pdf
* `csv`: text/csv

Commits
-------

f2ba0b3 [HttpFoundation] Add new MIME type mappings to `getMimeTypes()``

Author: fabpot

src/Symfony/Component/HttpFoundation/CHANGELOG.md

@@ -6,6 +6,7 @@ CHANGELOG
 
  * Deprecate using `Request::sendHeaders()` after headers have already been sent; use a `StreamedResponse` instead
  * Add support for the `QUERY` HTTP method
+ * Add support for structured MIME suffix
 
 7.3
 ---

src/Symfony/Component/HttpFoundation/Request.php

@@ -1226,8 +1226,20 @@ public static function getMimeTypes(string $format): array
 
     /**
      * Gets the format associated with the mime type.
+     *
+     *  Resolution order:
+     *   1) Exact match on the full MIME type (e.g. "application/json").
+     *   2) Match on the canonical MIME type (i.e. before the first ";" parameter).
+     *   3) If the type is "application/*+suffix", use the structured syntax suffix
+     *      mapping (e.g. "application/foo+json" → "json"), when available.
+     *   4) If $subtypeFallback is true and no match was found:
+     *      - return the MIME subtype (without "x-" prefix), provided it does not
+     *        contain a "+" (e.g. "application/x-yaml" → "yaml", "text/csv" → "csv").
+     *
+     * @param string|null $mimeType        The mime type to check
+     * @param bool        $subtypeFallback Whether to fall back to the subtype if no exact match is found
      */
-    public function getFormat(?string $mimeType): ?string
+    public function getFormat(?string $mimeType, bool $subtypeFallback = false): ?string
     {
         $canonicalMimeType = null;
         if ($mimeType && false !== $pos = strpos($mimeType, ';')) {
@@ -1247,6 +1259,27 @@ public function getFormat(?string $mimeType): ?string
             }
         }
 
+        if (!$canonicalMimeType) {
+            $canonicalMimeType = $mimeType;
+        }
+
+        if (str_starts_with($canonicalMimeType, 'application/') && str_contains($canonicalMimeType, '+')) {
+            $suffix = substr(strrchr($canonicalMimeType, '+'), 1);
+            if (isset(static::getStructuredSuffixFormats()[$suffix])) {
+                return static::getStructuredSuffixFormats()[$suffix];
+            }
+        }
+
+        if ($subtypeFallback && str_contains($canonicalMimeType, '/')) {
+            [, $subtype] = explode('/', $canonicalMimeType, 2);
+            if (str_starts_with($subtype, 'x-')) {
+                $subtype = substr($subtype, 2);
+            }
+            if (!str_contains($subtype, '+')) {
+                return $subtype;
+            }
+        }
+
         return null;
     }
 
@@ -1919,6 +1952,42 @@ protected static function initializeFormats(): void
             'atom' => ['application/atom+xml'],
             'rss' => ['application/rss+xml'],
             'form' => ['application/x-www-form-urlencoded', 'multipart/form-data'],
+            'soap' => ['application/soap+xml'],
+            'problem' => ['application/problem+json'],
+            'hal' => ['application/hal+json', 'application/hal+xml'],
+            'jsonapi' => ['application/vnd.api+json'],
+            'yaml' => ['text/yaml', 'application/x-yaml'],
+            'wbxml' => ['application/vnd.wap.wbxml'],
+            'pdf' => ['application/pdf'],
+            'csv' => ['text/csv'],
+        ];
+    }
+
+    /**
+     * Structured MIME suffix fallback formats
+     *
+     * This mapping is used when no exact MIME match is found in $formats.
+     * It enables handling of types like application/soap+xml → 'xml'.
+     *
+     * @see https://datatracker.ietf.org/doc/html/rfc6839
+     * @see https://datatracker.ietf.org/doc/html/rfc7303
+     * @see https://www.iana.org/assignments/media-types/media-types.xhtml
+     *
+     * @return array<string, string>
+     */
+    private static function getStructuredSuffixFormats(): array
+    {
+        return [
+            'json' => 'json',
+            'xml' => 'xml',
+            'xhtml' => 'html',
+            'cbor' => 'cbor',
+            'zip' => 'zip',
+            'ber' => 'asn1',
+            'der' => 'asn1',
+            'tlv' => 'tlv',
+            'wbxml' => 'xml',
+            'yaml' => 'yaml',
         ];
     }
 

src/Symfony/Component/HttpFoundation/Tests/RequestTest.php

@@ -527,6 +527,37 @@ public static function getFormatToMimeTypeMapProvider()
             ['rdf', ['application/rdf+xml']],
             ['atom', ['application/atom+xml']],
             ['form', ['application/x-www-form-urlencoded', 'multipart/form-data']],
+            ['rss', ['application/rss+xml']],
+            ['soap', ['application/soap+xml']],
+            ['html', ['application/xhtml+xml']],
+            ['problem', ['application/problem+json']],
+            ['hal', ['application/hal+json', 'application/hal+xml']],
+            ['jsonapi', ['application/vnd.api+json']],
+            ['yaml', ['application/x-yaml', 'text/yaml']],
+            ['wbxml', ['application/vnd.wap.wbxml']],
+        ];
+    }
+
+    /**
+     * @dataProvider getFormatWithSubtypeFallbackProvider
+     */
+    public function testGetFormatFromMimeTypeWithSubtypeFallback($expectedFormat, $mimeTypes)
+    {
+        $request = new Request();
+        foreach ($mimeTypes as $mime) {
+            $this->assertEquals($expectedFormat, $request->getFormat($mime, true));
+        }
+    }
+
+    public static function getFormatWithSubtypeFallbackProvider()
+    {
+        return [
+            ['cbor', ['application/example+cbor']],
+            ['asn1', ['application/ber-stream+ber', 'application/secure-data+der']],
+            ['zip', ['application/foobar+zip']],
+            ['tlv', ['application/device-config+tlv']],
+            ['pdf', ['application/pdf']],
+            ['csv', ['text/csv']],
         ];
     }