Allow different beginning and ending frontmatter delimiters.

src/formats/__tests__/frontmatter.spec.js

@@ -39,6 +39,18 @@ describe('Frontmatter', () => {
       );
   });
 
+  it('should parse YAML with custom delimiters when it is explicitly set as the format with different custom delimiters', () => {
+    expect(
+      frontmatterYAML(["~~~", "^^^"]).fromFile('~~~\ntitle: YAML\ndescription: Something longer\n^^^\nContent')
+    ).toEqual(
+      {
+        title: 'YAML',
+        description: 'Something longer',
+        body: 'Content',
+      }
+      );
+  });
+
   it('should parse YAML with ---yaml delimiters', () => {
     expect(
       FrontmatterInfer.fromFile('---yaml\ntitle: YAML\ndescription: Something longer\n---\nContent')
@@ -216,6 +228,24 @@ describe('Frontmatter', () => {
       );
   });
 
+  it('should stringify YAML with --- delimiters when it is explicitly set as the format with different custom delimiters', 
+  () => {
+    expect(
+      frontmatterYAML(["~~~", "^^^"]).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')
+      );
+  });
+
   it('should stringify TOML with +++ delimiters when it is explicitly set as the format without a custom delimiter',
   () => {
     expect(

src/formats/formats.js

@@ -1,3 +1,4 @@
+import { List } from 'immutable';
 import yamlFormatter from './yaml';
 import tomlFormatter from './toml';
 import jsonFormatter from './json';
@@ -54,7 +55,9 @@ function formatByName(name, customDelimiter) {
 
 export function resolveFormat(collectionOrEntity, entry) {
   // Check for custom delimiter
-  const customDelimiter = collectionOrEntity.get('frontmatter_delimiter');
+  const frontmatter_delimiter = collectionOrEntity.get('frontmatter_delimiter');
+  const customDelimiter = List.isList(frontmatter_delimiter) ? frontmatter_delimiter.toArray() : frontmatter_delimiter;
+
   // If the format is specified in the collection, use that format.
   const formatSpecification = collectionOrEntity.get('format');
   if (formatSpecification) {

website/site/content/docs/configuration-options.md

@@ -102,7 +102,7 @@ You may also specify a custom `extension` not included in the list above, as lon
 - `toml-frontmatter`: same as the `frontmatter` format above, except frontmatter will be both parsed and saved only as TOML, followed by unparsed body text. The default delimiter for this option is  `+++`.
 - `json-frontmatter`: same as the `frontmatter` format above, except frontmatter will be both parsed and saved as JSON, followed by unparsed body text. The default delimiter for this option is  `{` `}`.
 
-`frontmatter_delimiter`: if you have an explicit frontmatter format declared, this option allows you to specify a custom delimiter like `~~~`.
+`frontmatter_delimiter`: if you have an explicit frontmatter format declared, this option allows you to specify a custom delimiter like `~~~`. If you need different beginning and ending delimiters, you can use an array like `["(", ")"]`.
 
 
 ### `slug`