Add multi-format frontmatter parser

src/formats/__tests__/yaml-frontmatter.spec.js

@@ -0,0 +1,105 @@
+import YAMLFrontmatter from '../yaml-frontmatter';
+
+const YamlFrontmatterFormatter = new YAMLFrontmatter();
+
+describe('YAMLFrontmatter', () => {
+  it('should parse YAML with --- delimiters', () => {
+    expect(
+      YamlFrontmatterFormatter.fromFile('---\ntitle: YAML\ndescription: Something longer\n---\nContent')
+    ).toEqual(
+      {
+        title: 'YAML',
+        description: 'Something longer',
+        body: 'Content',
+      }
+    );
+  });
+
+  it('should parse YAML with ---yaml delimiters', () => {
+    expect(
+      YamlFrontmatterFormatter.fromFile('---yaml\ntitle: YAML\ndescription: Something longer\n---\nContent')
+    ).toEqual(
+      {
+        title: 'YAML',
+        description: 'Something longer',
+        body: 'Content',
+      }
+    );
+  });
+
+  it('should overwrite any body param in the front matter', () => {
+    expect(
+      YamlFrontmatterFormatter.fromFile('---\ntitle: The Title\nbody: Something longer\n---\nContent')
+    ).toEqual(
+      {
+        title: 'The Title',
+        body: 'Content',
+      }
+    );
+  });
+
+  it('should parse TOML with +++ delimiters', () => {
+    expect(
+      YamlFrontmatterFormatter.fromFile('+++\ntitle = "TOML"\ndescription = "Front matter"\n+++\nContent')
+    ).toEqual(
+      {
+        title: 'TOML',
+        description: 'Front matter',
+        body: 'Content',
+      }
+    );
+  });
+
+  it('should parse TOML with ---toml delimiters', () => {
+    expect(
+      YamlFrontmatterFormatter.fromFile('---toml\ntitle = "TOML"\ndescription = "Something longer"\n---\nContent')
+    ).toEqual(
+      {
+        title: 'TOML',
+        description: 'Something longer',
+        body: 'Content',
+      }
+    );
+  });
+
+  it('should parse JSON with { } delimiters', () => {
+    expect(
+      YamlFrontmatterFormatter.fromFile('{\n"title": "The Title",\n"description": "Something longer"\n}\nContent')
+    ).toEqual(
+      {
+        title: 'The Title',
+        description: 'Something longer',
+        body: 'Content',
+      }
+    );
+  });
+
+  it('should parse JSON with ---json delimiters', () => {
+    expect(
+      YamlFrontmatterFormatter.fromFile('---json\n{\n"title": "The Title",\n"description": "Something longer"\n}\n---\nContent')
+    ).toEqual(
+      {
+        title: 'The Title',
+        description: 'Something longer',
+        body: 'Content',
+      }
+    );
+  });
+
+  it('should stringify YAML with --- delimiters', () => {
+    expect(
+      YamlFrontmatterFormatter.toFile({ body: 'Some content\nOn another line', tags: ['front matter', 'yaml'], title: 'YAML' })
+    ).toEqual(
+      [
+        '---',
+        'tags:',
+        '  - front matter',
+        '  - yaml',
+        'title: YAML',
+        '---',
+        'Some content',
+        'On another line\n',
+      ].join('\n')
+    );
+  });
+});

src/formats/yaml-frontmatter.js

@@ -1,31 +1,31 @@
-import YAML from './yaml';
+import preliminaries from 'preliminaries';
+import yamlParser from 'preliminaries-parser-yaml';
+import tomlParser from 'preliminaries-parser-toml';
 
-const regexp = /^---\n([^]*?)\n---\n([^]*)$/;
+// Automatically register parsers
+preliminaries(true);
+yamlParser(true);
+tomlParser(true);
 
 export default class YAMLFrontmatter {
   fromFile(content) {
-    const match = content.match(regexp);
-    const obj = match ? new YAML().fromFile(match[1]) : {};
-    obj.body = match ? (match[2] || '').replace(/^\n+/, '') : content;
-    return obj;
+    const result = preliminaries.parse(content);
+    const data = result.data;
+    data.body = result.content;
+    return data;
   }
 
   toFile(data, sortedKeys) {
     const meta = {};
     let body = '';
-    let content = '';
-    for (var key in data) {
+    Object.keys(data).forEach((key) => {
       if (key === 'body') {
         body = data[key];
       } else {
         meta[key] = data[key];
       }
-    }
-
-    content += '---\n';
-    content += new YAML().toFile(meta, sortedKeys);
-    content += '---\n\n';
-    content += body;
-    return content;
+    });
+    // always stringify to YAML
+    return preliminaries.stringify(body, meta, { lang: 'yaml', delims: '---' });
   }
 }