diff --git a/lib/Parser/Construct.php b/lib/Parser/Construct.php
index b285487..ff88842 100644
--- a/lib/Parser/Construct.php
+++ b/lib/Parser/Construct.php
@@ -64,7 +64,7 @@ trait Construct {
     }
 
     protected function parseMediaType(string $type, ?Url $url = null): ?string {
-        if (preg_match('<^\s*([0-9a-z]+(?:/[!#$%&\'\*\+\-\.^_`|~0-9a-z]+)?)(?:\s|;|$)>i', $type, $match)) {
+        if (preg_match('<^\s*([0-9a-z]+(?:/[!#$%&\'\*\+\-\.^_`|~0-9a-z]+)?)(?:\s|;|,|$)>i', $type, $match)) {
             /* NOTE: The pattern used here is a subset of what is 
                 technically allowed by RFC 7231: the "type" portion
                 is supposed to be as general as the "subtype" portion,
@@ -91,6 +91,8 @@ trait Construct {
                     return ($this->mime ?? ($this->mime = new \Mimey\MimeTypes))->getMimeType($ext);
                 }
             }
+        } elseif ($url && $url->getScheme() === "data") {
+            return $this->parseMediaType($url->getPath()) ?? "text/plain";
         }
         return null;
     }
diff --git a/tests/cases/JSON/JSONTest.php b/tests/cases/JSON/JSONTest.php
index cf86d9b..fd33345 100644
--- a/tests/cases/JSON/JSONTest.php
+++ b/tests/cases/JSON/JSONTest.php
@@ -8,27 +8,26 @@ namespace JKingWeb\Lax\TestCase\JSON;
 
 /* Test format is as follows:
 
-    Each test is a JSON object with the following keys:
+    Each test is a YAML map with the following keys:
 
-    - `description`: a short human-readable description of the test
-    - `doc_url`: A fictitious URL where a newsfeed might be located, used for relative URL resolution
     - `input`: The test input, as a string or directly as a JSON Feed structure
     - `output`: The result of the parsing upon success; described in more detail below
     - `exception`: The exception ID thrown upon failure
+    - `type`: An HTTP Content-Type (with or without parameters) for the document
+    - `doc_url`: A fictitious URL where a newsfeed might be located, used for relative URL resolution
 
-    The 'description' and 'input' keys along with either 'output' or 'exception'
-    are required for all tests.
+    The 'input' key along with either 'output' or 'exception' are required for all tests.
 
-    The test output is necessarily mangled due to the limits of JSON:
+    The test output is necessarily mangled due to the limits of YAML:
 
     - Any field which should be an absolute URL should be written as a string,
       which will be transformed accordingly. Relative URLs should be represented
-      as an array with the relative part first, followed by the base that should
+      as a sequence with the relative part first, followed by the base that should
       be applied to it
-    - Any collections should be represented as arrays of objects, which will
+    - Any collections should be represented as sequences of maps, which will
       all be transformed accordingly
     - Rich text can either be supplied as a string (which will yield a Text object 
-      with plain-text content) or as an object with any of the properties of the
+      with plain-text content) or as a map with any of the properties of the
       Text class listed
 
     The transformations as performed by the `makeFeed` and `makeEntry` methods 
@@ -49,6 +48,9 @@ use JKingWeb\Lax\Enclosure\Enclosure;
 use JKingWeb\Lax\Person\Collection as PersonCollection;
 use JKingWeb\Lax\Category\Collection as CategoryCollection;
 use JKingWeb\Lax\Enclosure\Collection as EnclosureCollection;
+use Symfony\Component\Yaml\Yaml;
+use Symfony\Component\Yaml\Parser as YamlParser;
+
 
 /** 
  * @covers JKingWeb\Lax\Parser\Construct<extended>
@@ -75,12 +77,12 @@ class JSONTest extends \PHPUnit\Framework\TestCase {
     }
 
     public function provideJSONFeedVersion1(): iterable {
-        foreach (new \GlobIterator(__DIR__."/*.json", \FilesystemIterator::CURRENT_AS_PATHNAME | \FilesystemIterator::KEY_AS_FILENAME) as $file => $path) {
-            foreach (json_decode(file_get_contents($path)) as $index => $test) {
+        foreach (new \GlobIterator(__DIR__."/*.yaml", \FilesystemIterator::CURRENT_AS_PATHNAME | \FilesystemIterator::KEY_AS_FILENAME) as $file => $path) {
+            foreach ((new YamlParser)->parseFile($path, Yaml::PARSE_OBJECT_FOR_MAP) as $description => $test) {
                 if (isset($test->exception)) {
                     $test->output = new Exception((string) $test->exception);
                 }
-                yield "$file #$index: {$test->description}" => [
+                yield "$file: {$description}" => [
                     $test->input,
                     $test->type ?? "",
                     $test->doc_url ?? null,
@@ -204,4 +206,4 @@ class JSONTest extends \PHPUnit\Framework\TestCase {
             return new Url($url);
         }
     }
-}
\ No newline at end of file
+}
diff --git a/tests/cases/JSON/entry.json b/tests/cases/JSON/entry.json
deleted file mode 100644
index 51371d1..0000000
--- a/tests/cases/JSON/entry.json
+++ /dev/null
@@ -1,628 +0,0 @@
-[
-    {
-        "description": "Minimal entry",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "items": [{
-                "id": "1"
-            }]
-        },
-        "output": {
-            "format": "json",
-            "version": "1",
-            "entries": [
-                {
-                    "id": "1"
-                }
-            ]
-        }
-    },
-    {
-        "description": "Invalid entry 1 (no ID)",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "items": [{
-                "title": "Example title"
-            }]
-        },
-        "output": {
-            "format": "json",
-            "version": "1"
-        }
-    },
-    {
-        "description": "Invalid entry 2 (null ID)",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "items": [{
-                "id": null,
-                "title": "Example title"
-            }]
-        },
-        "output": {
-            "format": "json",
-            "version": "1"
-        }
-    },
-    {
-        "description": "Invalid entry 3 (boolean ID)",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "items": [{
-                "id": true,
-                "title": "Example title"
-            }]
-        },
-        "output": {
-            "format": "json",
-            "version": "1"
-        }
-    },
-    {
-        "description": "Invalid entry 4 (array ID)",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "items": [{
-                "id": ["1"],
-                "title": "Example title"
-            }]
-        },
-        "output": {
-            "format": "json",
-            "version": "1"
-        }
-    },
-    {
-        "description": "Invalid entry 5 (object ID)",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "items": [{
-                "id": {"id": "1"},
-                "title": "Example title"
-            }]
-        },
-        "output": {
-            "format": "json",
-            "version": "1"
-        }
-    },
-    {
-        "description": "Invalid entry 6 (empty string ID)",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "items": [{
-                "id": "",
-                "title": "Example title"
-            }]
-        },
-        "output": {
-            "format": "json",
-            "version": "1"
-        }
-    },
-    {
-        "description": "Integer ID",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "items": [{
-                "id": 1
-            }]
-        },
-        "output": {
-            "format": "json",
-            "version": "1",
-            "entries": [
-                {
-                    "id": "1"
-                }
-            ]
-        }
-    },
-    {
-        "description": "Float ID",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "items": [{
-                "id": 3.0e-10
-            }]
-        },
-        "output": {
-            "format": "json",
-            "version": "1",
-            "entries": [
-                {
-                    "id": "0.0000000003"
-                }
-            ]
-        }
-    },
-    {
-        "description": "Negative float ID",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "items": [{
-                "id": -3.0e-10
-            }]
-        },
-        "output": {
-            "format": "json",
-            "version": "1",
-            "entries": [
-                {
-                    "id": "-0.0000000003"
-                }
-            ]
-        }
-    },
-    {
-        "description": "Simple float ID",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "items": [{
-                "id": 0.3
-            }]
-        },
-        "output": {
-            "format": "json",
-            "version": "1",
-            "entries": [
-                {
-                    "id": "0.3"
-                }
-            ]
-        }
-    },
-    {
-        "description": "Bignum ID",
-        "input": "{\"version\": \"https://jsonfeed.org/version/1\",\"items\": [{\"id\": 9999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999}]}",
-        "output": {
-            "format": "json",
-            "version": "1",
-            "entries": [
-                {
-                    "id": "9999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999"
-                }
-            ]
-        }
-    },
-    {
-        "description": "Entry language",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "language": "en",
-            "items": [
-                {
-                    "id": 1,
-                    "language": "fr"
-                },
-                {
-                    "id": "2"
-                }
-            ]
-        },
-        "output": {
-            "format": "json",
-            "version": "1",
-            "lang": "en",
-            "entries": [
-                {
-                    "id": "1",
-                    "lang": "fr"
-                },
-                {
-                    "id": "2",
-                    "lang": "en"
-                }
-            ]
-        }
-    },
-    {
-        "description": "Entry banner",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "items": [
-                {
-                    "id": "1",
-                    "banner_image": "http://example.com/banner"
-                }
-            ]
-        },
-        "output": {
-            "format": "json",
-            "version": "1",
-            "entries": [
-                {
-                    "id": "1",
-                    "banner": "http://example.com/banner"
-                }
-            ]
-        }
-    },
-    {
-        "description": "Entry dates",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "items": [
-                {
-                    "id": "1",
-                    "date_published": "2020-03-03T21:12:42Z",
-                    "date_modified": "2020-03-03T21:12:42Z"
-                }
-            ]
-        },
-        "output": {
-            "format": "json",
-            "version": "1",
-            "entries": [
-                {
-                    "id": "1",
-                    "dateCreated": "2020-03-03T21:12:42Z",
-                    "dateModified": "2020-03-03T21:12:42Z"
-                }
-            ]
-        }
-    },
-    {
-        "description": "Entry URLs",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "items": [
-                {
-                    "id": "1",
-                    "url": "http://example.com/",
-                    "external_url": "http://example.org/"
-                }
-            ]
-        },
-        "output": {
-            "format": "json",
-            "version": "1",
-            "entries": [
-                {
-                    "id": "1",
-                    "link": "http://example.com/",
-                    "relatedLink": "http://example.org/"
-                }
-            ]
-        }
-    },
-    {
-        "description": "Entry title",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "items": [
-                {
-                    "id": "1",
-                    "title": "Example title"
-                }
-            ]
-        },
-        "output": {
-            "format": "json",
-            "version": "1",
-            "entries": [
-                {
-                    "id": "1",
-                    "title": "Example title"
-                }
-            ]
-        }
-    },
-    {
-        "description": "Entry summary",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "items": [
-                {
-                    "id": "1",
-                    "summary": "Example summary"
-                }
-            ]
-        },
-        "output": {
-            "format": "json",
-            "version": "1",
-            "entries": [
-                {
-                    "id": "1",
-                    "summary": "Example summary"
-                }
-            ]
-        }
-    },
-    {
-        "description": "Entry content (plain only)",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "items": [
-                {
-                    "id": "1",
-                    "content_text": "Plain content"
-                }
-            ]
-        },
-        "output": {
-            "format": "json",
-            "version": "1",
-            "entries": [
-                {
-                    "id": "1",
-                    "content": {
-                        "plain": "Plain content"
-                    }
-                }
-            ]
-        }
-    },
-    {
-        "description": "Entry content (HTML only)",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "items": [
-                {
-                    "id": "1",
-                    "content_html": "HTML content"
-                }
-            ]
-        },
-        "output": {
-            "format": "json",
-            "version": "1",
-            "entries": [
-                {
-                    "id": "1",
-                    "content": {
-                        "html": "HTML content"
-                    }
-                }
-            ]
-        }
-    },
-    {
-        "description": "Entry content (mixed)",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "items": [
-                {
-                    "id": "1",
-                    "content_text": "Plain content",
-                    "content_html": "HTML content"
-                }
-            ]
-        },
-        "output": {
-            "format": "json",
-            "version": "1",
-            "entries": [
-                {
-                    "id": "1",
-                    "content": {
-                        "plain": "Plain content",
-                        "html": "HTML content"
-                    }
-                }
-            ]
-        }
-    },
-    {
-        "description": "Entry categories",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "items": [
-                {
-                    "id": "1",
-                    "tags": ["this", "that", "the other thing", "", null, false, 1, 3.0, " "]
-                }
-            ]
-        },
-        "output": {
-            "format": "json",
-            "version": "1",
-            "entries": [
-                {
-                    "id": "1",
-                    "categories": [
-                        {"name": "this"},
-                        {"name": "that"},
-                        {"name": "the other thing"},
-                        {"name": " "}
-                    ]
-                }
-            ]
-        }
-    },
-    {
-        "description": "Entry authors",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "authors": [
-                {"name": "Jane Doe"},
-                {"name": "John Doe"}
-            ],
-            "items": [
-                {
-                    "id": 1,
-                    "author": {"name": "John Doe"},
-                    "authors": [{"name": "Jane Doe"}]
-                },
-                {
-                    "id": 2,
-                    "author": {"name": "John Doe"}
-                },
-                {
-                    "id": 3,
-                    "authors": [{"name": "Jane Doe"}]
-                },
-                {
-                    "id": 4
-                },
-                {
-                    "id": 5,
-                    "authors": [{"NAME": "Jane Doe"}]
-                }
-            ]
-        },
-        "output": {
-            "format": "json",
-            "version": "1",
-            "people": [
-                {"name": "Jane Doe", "role": "author"},
-                {"name": "John Doe", "role": "author"}
-            ],
-            "entries": [
-                {"id": "1", "people": [{"name": "Jane Doe", "role": "author"}]},
-                {"id": "2", "people": [{"name": "John Doe", "role": "author"}]},
-                {"id": "3", "people": [{"name": "Jane Doe", "role": "author"}]},
-                {"id": "4", "people": [{"name": "Jane Doe", "role": "author"},{"name": "John Doe", "role": "author"}]},
-                {"id": "5", "people": [{"name": "Jane Doe", "role": "author"},{"name": "John Doe", "role": "author"}]}
-            ]
-        }
-    },
-    {
-        "description": "Entry image",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "items": [{
-                "id": "1",
-                "image": "http://example.com/image"
-            }]
-        },
-        "output": {
-            "format": "json",
-            "version": "1",
-            "entries": [
-                {
-                    "id": "1",
-                    "enclosures": [
-                        {
-                            "type": "image",
-                            "url": "http://example.com/image",
-                            "preferred": true
-                        }
-                    ]
-                }
-            ]
-        }
-    },
-    {
-        "description": "Entry attachments",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "items": [{
-                "id": "1",
-                "attachments": [
-                    {
-                        "url": "http://example.com/image",
-                        "mime_type": "image/svg+xml; charset=\"urf-8\"",
-                        "title": "Logo",
-                        "size_in_bytes": 2345
-                    },
-                    {
-                        "url": "http://example.com/graphic.png"
-                    },
-                    {
-                        "url": "http://example.com/graphic.PNG"
-                    },
-                    {
-                        "url": "data:text/plain,Hello%20World!",
-                        "title": "Example text"
-                    },
-                    {
-                        "url": "data:text/plain,File:example.jpg",
-                        "title": "Sneaky URN"
-                    },
-                    {
-                        "url": "http://example.com/talk",
-                        "mime_type": "audio",
-                        "duration_in_seconds": 72
-                    },
-                    {
-                        "title": "Invalid URL",
-                        "url": "http://[.com/bogus"
-                    },
-                    {
-                        "title": "No URL"
-                    }
-                ]
-            }]
-        },
-        "output": {
-            "format": "json",
-            "version": "1",
-            "entries": [
-                {
-                    "id": "1",
-                    "enclosures": [
-                        {
-                            "type": "image/svg+xml",
-                            "url": "http://example.com/image",
-                            "title": "Logo",
-                            "size": 2345
-                        },
-                        {
-                            "type": "image/png",
-                            "url": "http://example.com/graphic.png"
-                        },
-                        {
-                            "type": "image/png",
-                            "url": "http://example.com/graphic.PNG"
-                        },
-                        {
-                            "url": "data:text/plain,Hello%20World!",
-                            "title": "Example text"
-                        },
-                        {
-                            "url": "data:text/plain,File:example.jpg",
-                            "title": "Sneaky URN"
-                        },
-                        {
-                            "url": "http://example.com/talk",
-                            "type": "audio",
-                            "duration": 72
-                        }
-                    ]
-                }
-            ]
-        }
-    },
-    {
-        "description": "Entry image and attachments",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "items": [{
-                "id": "1",
-                "attachments": [
-                    {
-                        "url": "http://example.com/image",
-                        "mime_type": "image/svg+xml; charset=\"urf-8\"",
-                        "title": "Logo",
-                        "size_in_bytes": 2345
-                    }
-                ],
-                "image": "http://example.com/image"
-            }]
-        },
-        "output": {
-            "format": "json",
-            "version": "1",
-            "entries": [
-                {
-                    "id": "1",
-                    "enclosures": [
-                        {
-                            "type": "image",
-                            "url": "http://example.com/image",
-                            "preferred": true
-                        },
-                        {
-                            "type": "image/svg+xml",
-                            "url": "http://example.com/image",
-                            "title": "Logo",
-                            "size": 2345
-                        }
-                    ]
-                }
-            ]
-        }
-    }
-]
\ No newline at end of file
diff --git a/tests/cases/JSON/entry.yaml b/tests/cases/JSON/entry.yaml
new file mode 100644
index 0000000..56b0f52
--- /dev/null
+++ b/tests/cases/JSON/entry.yaml
@@ -0,0 +1,547 @@
+Minimal entry:
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "items": [{
+                "id": "1"
+            }]
+        }
+    output:
+        format: json
+        version: '1'
+        entries:
+            - id: '1'
+
+Invalid entry 1: # no ID
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "items": [{
+                "title": "Example title"
+            }]
+        }
+    output:
+        format: json
+        version: '1'
+
+Invalid entry 2: # null ID
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "items": [{
+                "title": "Example title",
+                "id": null
+            }]
+        }
+    output:
+        format: json
+        version: '1'
+
+Invalid entry 3: # boolean ID
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "items": [{
+                "title": "Example title",
+                "id": true
+            }]
+        }
+    output:
+        format: json
+        version: '1'
+
+Invalid entry 4: # array ID
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "items": [{
+                "title": "Example title",
+                "id": ["1"]
+            }]
+        }
+    output:
+        format: json
+        version: '1'
+
+Invalid entry 5: # object ID
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "items": [{
+                "title": "Example title",
+                "id": {"id": "1"}
+            }]
+        }
+    output:
+        format: json
+        version: '1'
+
+Invalid entry 6: # empty string ID
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "items": [{
+                "title": "Example title",
+                "id": ""
+            }]
+        }
+    output:
+        format: json
+        version: '1'
+
+Integer ID:
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "items": [{
+                "id": 1
+            }]
+        }
+    output:
+        format: json
+        version: '1'
+        entries:
+            - id: '1'
+
+Float ID:
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "items": [{
+                "id": 3.0e-10
+            }]
+        }
+    output:
+        format: json
+        version: '1'
+        entries:
+            - id: '0.0000000003'
+
+Negative float ID:
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "items": [{
+                "id": -3.0e-10
+            }]
+        }
+    output:
+        format: json
+        version: '1'
+        entries:
+            - id: '-0.0000000003'
+
+Simple float ID:
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "items": [{
+                "id": 0.3
+            }]
+        }
+    output:
+        format: json
+        version: '1'
+        entries:
+            - id: '0.3'
+
+Bignum ID:
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "items": [{
+                "id": 9999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999
+            }]
+        }
+    output:
+        format: json
+        version: '1'
+        entries:
+            - id: '9999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999'
+
+Entry language:
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "language": "en",
+            "items": [
+                {
+                    "id": 1,
+                    "language": "fr"
+                },
+                {
+                    "id": "2"
+                }
+            ]
+        }
+    output:
+        format: json
+        version: '1'
+        lang: en
+        entries:
+            - id: '1'
+              lang: fr
+            - id: '2'
+              lang: en
+
+Entry banner:
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "items": [
+                {
+                    "id": "1",
+                    "banner_image": "http://example.com/banner"
+                }
+            ]
+        }
+    output:
+        format: json
+        version: '1'
+        entries:
+            - id: '1'
+              banner: 'http://example.com/banner'
+
+Entry dates:
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "items": [
+                {
+                    "id": "1",
+                    "date_published": "2020-03-03T21:12:42Z",
+                    "date_modified": "2020-03-03T21:12:42Z"
+                }
+            ]
+        }
+    output:
+        format: json
+        version: '1'
+        entries:
+            - id: '1'
+              dateCreated: '2020-03-03T21:12:42Z'
+              dateModified: '2020-03-03T21:12:42Z'
+
+Entry URLs:
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "items": [
+                {
+                    "id": "1",
+                    "url": "http://example.com/",
+                    "external_url": "http://example.org/"
+                }
+            ]
+        }
+    output:
+        format: json
+        version: '1'
+        entries:
+            - id: '1'
+              link: 'http://example.com/'
+              relatedLink: 'http://example.org/'
+
+Entry title:
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "items": [
+                {
+                    "id": "1",
+                    "title": "Example title"
+                }
+            ]
+        }
+    output:
+        format: json
+        version: '1'
+        entries:
+            - id: '1'
+              title: 'Example title'
+
+Entry summary:
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "items": [
+                {
+                    "id": "1",
+                    "summary": "Example summary"
+                }
+            ]
+        }
+    output:
+        format: json
+        version: '1'
+        entries:
+            - id: '1'
+              summary: 'Example summary'
+
+Entry content (plain only):
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "items": [
+                {
+                    "id": "1",
+                    "content_text": "Plain content"
+                }
+            ]
+        }
+    output:
+        format: json
+        version: '1'
+        entries:
+            - id: '1'
+              content:
+                plain: 'Plain content'
+
+Entry content (HTML only):
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "items": [
+                {
+                    "id": "1",
+                    "content_html": "HTML content"
+                }
+            ]
+        }
+    output:
+        format: json
+        version: '1'
+        entries:
+            - id: '1'
+              content:
+                html: 'HTML content'
+
+Entry content (mixed):
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "items": [
+                {
+                    "id": "1",
+                    "content_text": "Plain content",
+                    "content_html": "HTML content"
+                }
+            ]
+        }
+    output:
+        format: json
+        version: '1'
+        entries:
+            - id: '1'
+              content:
+                plain: 'Plain content'
+                html: 'HTML content'
+
+Entry categories:
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "items": [
+                {
+                    "id": "1",
+                    "tags": ["this", "that", "the other thing", "", null, false, 1, 3.0, " "]
+                }
+            ]
+        }
+    output:
+        format: json
+        version: '1'
+        entries:
+            - id: '1'
+              categories:
+                - name: this
+                - name: that
+                - name: 'the other thing'
+                - name: ' '
+
+Entry authors:
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "authors": [
+                {"name": "Jane Doe"},
+                {"name": "John Doe"}
+            ],
+            "items": [
+                {
+                    "id": 1,
+                    "author": {"name": "John Doe"},
+                    "authors": [{"name": "Jane Doe"}]
+                },
+                {
+                    "id": 2,
+                    "author": {"name": "John Doe"}
+                },
+                {
+                    "id": 3,
+                    "authors": [{"name": "Jane Doe"}]
+                },
+                {
+                    "id": 4
+                },
+                {
+                    "id": 5,
+                    "authors": [{"NAME": "Jane Doe"}]
+                }
+            ]
+        }
+    output:
+        format: json
+        version: '1'
+        people:
+            - name: Jane Doe
+              role: author
+            - name: John Doe
+              role: author
+        entries:
+            - id: '1'
+              people:
+                - name: Jane Doe
+                  role: author
+            - id: '2'
+              people:
+                - name: John Doe
+                  role: author
+            - id: '3'
+              people:
+                - name: Jane Doe
+                  role: author
+            - id: '4'
+              people:
+                - name: Jane Doe
+                  role: author
+                - name: John Doe
+                  role: author
+            - id: '5'
+              people:
+                - name: Jane Doe
+                  role: author
+                - name: John Doe
+                  role: author
+
+Entry image:
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "items": [{
+                "id": "1",
+                "image": "http://example.com/image"
+            }]
+        }
+    output:
+        format: json
+        version: '1'
+        entries:
+            - id: '1'
+              enclosures:
+                - url: 'http://example.com/image'
+                  type: image
+                  preferred: true
+
+Entry attachments:
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "items": [{
+                "id": "1",
+                "attachments": [
+                    {
+                        "url": "http://example.com/image",
+                        "mime_type": "image/svg+xml; charset=\"urf-8\"",
+                        "title": "Logo",
+                        "size_in_bytes": 2345
+                    },
+                    {
+                        "url": "http://example.com/graphic.png"
+                    },
+                    {
+                        "url": "http://example.com/graphic.PNG"
+                    },
+                    {
+                        "url": "data:text/rtf,Hello%20World!",
+                        "title": "Example text"
+                    },
+                    {
+                        "url": "data:,Hello%20World!",
+                        "title": "Example text"
+                    },
+                    {
+                        "url": "urn:bogus:example.jpg",
+                        "title": "Sneaky URN"
+                    },
+                    {
+                        "url": "http://example.com/talk",
+                        "mime_type": "audio",
+                        "duration_in_seconds": 72
+                    },
+                    {
+                        "title": "Invalid URL",
+                        "url": "http://[.com/bogus"
+                    },
+                    {
+                        "title": "No URL"
+                    }
+                ]
+            }]
+        }
+    output:
+        format: json
+        version: '1'
+        entries:
+            - id: '1'
+              enclosures:
+                - url: 'http://example.com/image'
+                  type: 'image/svg+xml'
+                  title: Logo
+                  size: 2345
+                - url: 'http://example.com/graphic.png'
+                  type: 'image/png'
+                - url: 'http://example.com/graphic.PNG'
+                  type: 'image/png'
+                - url: 'data:text/rtf,Hello%20World!'
+                  type: 'text/rtf'
+                  title: 'Example text'
+                - url: 'data:,Hello%20World!'
+                  type: 'text/plain'
+                  title: 'Example text'
+                - url: 'urn:bogus:example.jpg'
+                  title: 'Sneaky URN'
+                - url: 'http://example.com/talk'
+                  type: 'audio'
+                  duration: 72
+
+Entry image and attachments:
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "items": [{
+                "id": "1",
+                "attachments": [
+                    {
+                        "url": "http://example.com/logo",
+                        "mime_type": "image/svg+xml; charset=\"urf-8\"",
+                        "title": "Logo",
+                        "size_in_bytes": 2345
+                    }
+                ],
+                "image": "http://example.com/image"
+            }]
+        }
+    output:
+        format: json
+        version: '1'
+        entries:
+            - id: '1'
+              enclosures:
+                - url: 'http://example.com/image'
+                  type: image
+                  preferred: true
+                - url: 'http://example.com/logo'
+                  type: 'image/svg+xml'
+                  title: Logo
+                  size: 2345
diff --git a/tests/cases/JSON/failures.json b/tests/cases/JSON/failures.json
deleted file mode 100644
index 0bb8d1b..0000000
--- a/tests/cases/JSON/failures.json
+++ /dev/null
@@ -1,33 +0,0 @@
-[
-    {
-        "description": "Content-Type mismatch",
-        "type": "text/html",
-        "input": {"version": "https://jsonfeed.org/version/1"},
-        "exception": "notJSONType"
-    },
-    {
-        "description": "Not valid JSON 1",
-        "input": "{",
-        "exception": "notJSON"
-    },
-    {
-        "description": "Not valid JSON 2",
-        "input": "<rss><channel/></rss>",
-        "exception": "notJSON"
-    },
-    {
-        "description": "Not a JSON feed 1",
-        "input": "{}",
-        "exception": "notJSONFeed"
-    },
-    {
-        "description": "Not a JSON feed 2",
-        "input": {"version": "https://example.com/"},
-        "exception": "notJSONFeed"
-    },
-    {
-        "description": "Not a JSON feed 3",
-        "input": {"version": "https://jsonfeed.org/version/"},
-        "exception": "notJSONFeed"
-    }
-]
\ No newline at end of file
diff --git a/tests/cases/JSON/failures.yaml b/tests/cases/JSON/failures.yaml
new file mode 100644
index 0000000..b68a4f8
--- /dev/null
+++ b/tests/cases/JSON/failures.yaml
@@ -0,0 +1,24 @@
+Content-Type mismatch:
+    type: text/html
+    input: '{"version": "https://jsonfeed.org/version/1"}'
+    exception: notJSONType
+
+Not valid JSON 1:
+    input: '{'
+    exception: notJSON
+
+Not valid JSON 2:
+    input: '<rss><channel/></rss>'
+    exception: notJSON
+
+Not a JSON feed 1:
+    input: '{}'
+    exception: notJSONFeed
+
+Not a JSON feed 2:
+    input: '{"version": "https://example.com/"}'
+    exception: notJSONFeed
+
+Not a JSON feed 3:
+    input: '{"version": "https://jsonfeed.org/version/"}'
+    exception: notJSONFeed
diff --git a/tests/cases/JSON/feed.json b/tests/cases/JSON/feed.json
deleted file mode 100644
index c196efe..0000000
--- a/tests/cases/JSON/feed.json
+++ /dev/null
@@ -1,261 +0,0 @@
-[
-    {
-        "description": "Minimal example 1",
-        "input": {
-            "version": "https://jsonfeed.org/version/1"
-        },
-        "output": {
-            "format": "json",
-            "version": "1"
-        }
-    },
-    {
-        "description": "Minimal example 2",
-        "input": {
-            "version": "https://jsonfeed.org/version/1.1"
-        },
-        "output": {
-            "format": "json",
-            "version": "1.1"
-        }
-    },
-    {
-        "description": "Correct type of member",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "title": "Example title"
-        },
-        "output": {
-            "format": "json",
-            "version": "1",
-            "title": "Example title"
-        }
-    },
-    {
-        "description": "Incorrect type of member",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "title": 1001001
-        },
-        "output": {
-            "format": "json",
-            "version": "1"
-        }
-    },
-    {
-        "description": "URL -> ID equivalence",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "title": "Example title",
-            "feed_url": "http://example.com/"
-        },
-        "output": {
-            "format": "json",
-            "version": "1",
-            "title": "Example title",
-            "id": "http://example.com/",
-            "url": "http://example.com/"
-        }
-    },
-    {
-        "description": "Single author",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "author": {"name": "John Doe", "url": "http://example.org/", "avatar": "http://example.org/avatar"}
-        },
-        "output": {
-            "format": "json",
-            "version": "1",
-            "people": [
-                {
-                    "role": "author",
-                    "name": "John Doe",
-                    "url": "http://example.org/",
-                    "avatar": "http://example.org/avatar"
-                }
-            ]
-        }
-    },
-    {
-        "description": "Multiple authors",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "authors": [
-                {"name": "John Doe", "url": "http://example.org/", "avatar": "http://example.org/avatar"},
-                {"name": "Jane Doe", "url": "http://example.net/", "avatar": "http://example.net/avatar"}
-            ]
-        },
-        "output": {
-            "format": "json",
-            "version": "1",
-            "people": [
-                {
-                    "role": "author",
-                    "name": "John Doe",
-                    "url": "http://example.org/",
-                    "avatar": "http://example.org/avatar"
-                },
-                {
-                    "role": "author",
-                    "name": "Jane Doe",
-                    "url": "http://example.net/",
-                    "avatar": "http://example.net/avatar"
-                }
-            ]
-        }
-    },
-    {
-        "description": "Fallback author",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "authors": [
-                {"name": "John Doe", "url": "http://example.org/", "avatar": "http://example.org/avatar"},
-                {"name": "Jane Doe", "url": "http://example.net/", "avatar": "http://example.net/avatar"}
-            ],
-            "author": {"name": "John Smith", "url": "http://example.biz/", "avatar": "http://example.biz/avatar"}
-        },
-        "output": {
-            "format": "json",
-            "version": "1",
-            "people": [
-                {
-                    "role": "author",
-                    "name": "John Doe",
-                    "url": "http://example.org/",
-                    "avatar": "http://example.org/avatar"
-                },
-                {
-                    "role": "author",
-                    "name": "Jane Doe",
-                    "url": "http://example.net/",
-                    "avatar": "http://example.net/avatar"
-                }
-            ]
-        }
-    },
-    {
-        "description": "Empty author",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "author": {}
-        },
-        "output": {
-            "format": "json",
-            "version": "1"
-        }
-    },
-    {
-        "description": "Empty authors",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "authors": [{}]
-        },
-        "output": {
-            "format": "json",
-            "version": "1"
-        }
-    },
-    {
-        "description": "Empty authors with fallback",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "authors": [{}],
-            "author": {"name": "John Doe", "url": "http://example.org/", "avatar": "http://example.org/avatar"}
-        },
-        "output": {
-            "format": "json",
-            "version": "1",
-            "people": [
-                {
-                    "role": "author",
-                    "name": "John Doe",
-                    "url": "http://example.org/",
-                    "avatar": "http://example.org/avatar"
-                }
-            ]
-        }
-    },
-    {
-        "description": "Expired feed",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "expired": true
-        },
-        "output": {
-            "format": "json",
-            "version": "1",
-            "sched": {
-                "expired": true
-            }
-        }
-    },
-    {
-        "description": "Not expired feed",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "expired": false
-        },
-        "output": {
-            "format": "json",
-            "version": "1",
-            "sched": {
-                "expired": false
-            }
-        }
-    },
-    {
-        "description": "Invalidly expired feed",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "expired": 1
-        },
-        "output": {
-            "format": "json",
-            "version": "1"
-        }
-    },
-    {
-        "description": "Basic example",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "language": "en",
-            "title": "Example title",
-            "feed_url": "http://example.com/",
-            "home_page_url": "http://example.net/",
-            "description": "Example description",
-            "user_comment": "Example comment",
-            "next_url": "http://example.com/next",
-            "icon": "http://example.com/image",
-            "favicon": "http://example.com/icon"
-        },
-        "output": {
-            "format": "json",
-            "version": "1",
-            "lang": "en",
-            "title": "Example title",
-            "id": "http://example.com/",
-            "url": "http://example.com/",
-            "link": "http://example.net/",
-            "summary": "Example description",
-            "icon": "http://example.com/icon",
-            "image": "http://example.com/image"
-        }
-    },
-    {
-        "description": "Relative URL resolution",
-        "doc_url": "http://example.com",
-        "input": {
-            "version": "https://jsonfeed.org/version/1",
-            "feed_url": "feed.json"
-        },
-        "output": {
-            "meta": {
-                "url": "http://example.com"
-            },
-            "format": "json",
-            "version": "1",
-            "id": "feed.json",
-            "url": ["feed.json", "http://example.com"]
-        }
-    }
-]
\ No newline at end of file
diff --git a/tests/cases/JSON/feed.yaml b/tests/cases/JSON/feed.yaml
new file mode 100644
index 0000000..6cfd122
--- /dev/null
+++ b/tests/cases/JSON/feed.yaml
@@ -0,0 +1,221 @@
+Minimal example 1:
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1"
+        }
+    output:
+        format: json
+        version: '1'
+
+Minimal example 2:
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1.1"
+        }
+    output:
+        format: json
+        version: '1.1'
+
+Correct type of member:
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "title": "Example title"
+        }
+    output:
+        format: json
+        version: '1'
+        title: 'Example title'
+
+Incorrect type of member:
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "title": 1001001
+        }
+    output:
+        format: json
+        version: '1'
+
+URL -> ID equivalence:
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "feed_url": "http://example.com/"
+        }
+    output:
+        format: json
+        version: '1'
+        id: 'http://example.com/'
+        url: 'http://example.com/'
+
+Single author:
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "author": {"name": "John Doe", "url": "http://example.org/", "avatar": "http://example.org/avatar"}
+        }
+    output:
+        format: json
+        version: '1'
+        people:
+            - role: author
+              name: John Doe
+              url: 'http://example.org/'
+              avatar: http://example.org/avatar
+
+Multiple authors:
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "authors": [
+                {"name": "John Doe", "url": "http://example.org/", "avatar": "http://example.org/avatar"},
+                {"name": "Jane Doe", "url": "http://example.net/", "avatar": "http://example.net/avatar"}
+            ]
+        }
+    output:
+        format: json
+        version: '1'
+        people:
+            - role: author
+              name: John Doe
+              url: 'http://example.org/'
+              avatar: http://example.org/avatar
+            - role: author
+              name: Jane Doe
+              url: 'http://example.net/'
+              avatar: http://example.net/avatar
+
+Fallback author:
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "authors": [
+                {"name": "John Doe", "url": "http://example.org/", "avatar": "http://example.org/avatar"},
+                {"name": "Jane Doe", "url": "http://example.net/", "avatar": "http://example.net/avatar"}
+            ],
+            "author": {"name": "John Smith", "url": "http://example.biz/", "avatar": "http://example.biz/avatar"}
+        }
+    output:
+        format: json
+        version: '1'
+        people:
+            - role: author
+              name: John Doe
+              url: 'http://example.org/'
+              avatar: http://example.org/avatar
+            - role: author
+              name: Jane Doe
+              url: 'http://example.net/'
+              avatar: http://example.net/avatar
+
+Empty author:
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "author": {}
+        }
+    output:
+        format: json
+        version: '1'
+
+Empty authors:
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "authors": [{}]
+        }
+    output:
+        format: json
+        version: '1'
+
+Empty authors with fallback:
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "authors": [{}],
+            "author": {"name": "John Doe", "url": "http://example.org/", "avatar": "http://example.org/avatar"}
+        }
+    output:
+        format: json
+        version: '1'
+        people:
+            - role: author
+              name: John Doe
+              url: 'http://example.org/'
+              avatar: http://example.org/avatar
+
+Expired feed:
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "expired": true
+        }
+    output:
+        format: json
+        version: '1'
+        sched:
+            expired: true
+
+Not expired feed:
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "expired": false
+        }
+    output:
+        format: json
+        version: '1'
+        sched:
+            expired: false
+
+Improperly expired feed: # the 'expired' JSON Feed key is explicitly a boolean
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "expired": 1
+        }
+    output:
+        format: json
+        version: '1'
+
+Multiple elements:
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "language": "en",
+            "title": "Example title",
+            "feed_url": "http://example.com/",
+            "home_page_url": "http://example.net/",
+            "description": "Example description",
+            "user_comment": "Example comment",
+            "next_url": "http://example.com/next",
+            "icon": "http://example.com/image",
+            "favicon": "http://example.com/icon"
+        }
+    output:
+            format: json
+            version: '1'
+            lang: en
+            title: Example title
+            id: 'http://example.com/'
+            url: 'http://example.com/'
+            link: 'http://example.net/'
+            summary: Example description
+            icon: 'http://example.com/icon'
+            image: 'http://example.com/image'
+
+Relative URL resolution:
+    doc_url: 'http://example.com'
+    input: >
+        {
+            "version": "https://jsonfeed.org/version/1",
+            "feed_url": "feed.json"
+        }
+    output:
+        meta:
+            url: 'http://example.com'
+        format: json
+        version: '1'
+        id: 'feed.json'
+        url: ['feed.json', 'http://example.com']
diff --git a/vendor-bin/phpunit/composer.json b/vendor-bin/phpunit/composer.json
index f76e141..bc16564 100644
--- a/vendor-bin/phpunit/composer.json
+++ b/vendor-bin/phpunit/composer.json
@@ -1,5 +1,6 @@
 {
     "require-dev": {
-        "phpunit/phpunit": "^9.0"
+        "phpunit/phpunit": "^9.0",
+        "symfony/yaml": "^5.0"
     }
 }
diff --git a/vendor-bin/phpunit/composer.lock b/vendor-bin/phpunit/composer.lock
index 128459d..5319864 100644
--- a/vendor-bin/phpunit/composer.lock
+++ b/vendor-bin/phpunit/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "b7670d90fa803400168312d1b096854c",
+    "content-hash": "5f6ef85b0137813e2008ed286079c104",
     "packages": [],
     "packages-dev": [
         {
@@ -1501,6 +1501,65 @@
             ],
             "time": "2020-01-13T11:15:53+00:00"
         },
+        {
+            "name": "symfony/yaml",
+            "version": "v5.0.5",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/symfony/yaml.git",
+                "reference": "a4b613d7e44f62941adff5a802cff70adee57d3f"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/symfony/yaml/zipball/a4b613d7e44f62941adff5a802cff70adee57d3f",
+                "reference": "a4b613d7e44f62941adff5a802cff70adee57d3f",
+                "shasum": ""
+            },
+            "require": {
+                "php": "^7.2.5",
+                "symfony/polyfill-ctype": "~1.8"
+            },
+            "conflict": {
+                "symfony/console": "<4.4"
+            },
+            "require-dev": {
+                "symfony/console": "^4.4|^5.0"
+            },
+            "suggest": {
+                "symfony/console": "For validating YAML files using the lint command"
+            },
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "5.0-dev"
+                }
+            },
+            "autoload": {
+                "psr-4": {
+                    "Symfony\\Component\\Yaml\\": ""
+                },
+                "exclude-from-classmap": [
+                    "/Tests/"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Fabien Potencier",
+                    "email": "fabien@symfony.com"
+                },
+                {
+                    "name": "Symfony Community",
+                    "homepage": "https://symfony.com/contributors"
+                }
+            ],
+            "description": "Symfony Yaml Component",
+            "homepage": "https://symfony.com",
+            "time": "2020-02-03T13:51:17+00:00"
+        },
         {
             "name": "theseer/tokenizer",
             "version": "1.1.3",