feat(v2): read first heading as title and use it in front-matter (#4485)

* feat(v2): read first heading as title and pass it to front-matter

* fix(v2): always trim content after extracting front-matter

* fix(v2): remove heading from rss and keep duplicate heading

* fix(v2): rollback some unnecessary comment changes

* test(v2): add unit tests to blog

* test(v2): add unit tests to docs

* test(v2): correct issue on windows

* test(v2): add additional test cases

packages/docusaurus-plugin-content-docs/src/__tests__/__fixtures__/simple-site/docs/headingAsTitle.md

@@ -0,0 +1 @@
+# My heading as title

packages/docusaurus-plugin-content-docs/src/__tests__/__snapshots__/index.test.ts.snap

@@ -67,6 +67,11 @@ Object {
               "path": "/docs/foo/bazSlug.html",
               "sidebar": "docs",
             },
+            Object {
+              "id": "headingAsTitle",
+              "path": "/docs/headingAsTitle",
+              "sidebar": undefined,
+            },
             Object {
               "id": "hello",
               "path": "/docs/",
@@ -172,6 +177,17 @@ Object {
     \\"title\\": \\"Hello, World !\\",
     \\"permalink\\": \\"/docs/\\"
   }
+}",
+  "site-docs-heading-as-title-md-c6d.json": "{
+  \\"unversionedId\\": \\"headingAsTitle\\",
+  \\"id\\": \\"headingAsTitle\\",
+  \\"isDocsHomePage\\": false,
+  \\"title\\": \\"My heading as title\\",
+  \\"description\\": \\"\\",
+  \\"source\\": \\"@site/docs/headingAsTitle.md\\",
+  \\"slug\\": \\"/headingAsTitle\\",
+  \\"permalink\\": \\"/docs/headingAsTitle\\",
+  \\"version\\": \\"current\\"
 }",
   "site-docs-hello-md-9df.json": "{
   \\"unversionedId\\": \\"hello\\",
@@ -383,6 +399,11 @@ Object {
               "path": "/docs/foo/bazSlug.html",
               "sidebar": "docs",
             },
+            Object {
+              "id": "headingAsTitle",
+              "path": "/docs/headingAsTitle",
+              "sidebar": undefined,
+            },
             Object {
               "id": "hello",
               "path": "/docs/",
@@ -494,6 +515,14 @@ Array [
         },
         "path": "/docs/foo/bazSlug.html",
       },
+      Object {
+        "component": "@theme/DocItem",
+        "exact": true,
+        "modules": Object {
+          "content": "@site/docs/headingAsTitle.md",
+        },
+        "path": "/docs/headingAsTitle",
+      },
       Object {
         "component": "@theme/DocItem",
         "exact": true,
@@ -579,6 +608,7 @@ These sidebar document ids do not exist:
 Available document ids=
 - foo/bar
 - foo/baz
+- headingAsTitle
 - hello
 - ipsum
 - lorem

packages/docusaurus-plugin-content-docs/src/__tests__/docs.test.ts

@@ -160,6 +160,7 @@ describe('simple site', () => {
         'rootRelativeSlug.md',
         'rootResolvedSlug.md',
         'rootTryToEscapeSlug.md',
+        'headingAsTitle.md',
         'foo/bar.md',
         'foo/baz.md',
         'slugs/absoluteSlug.md',

packages/docusaurus-plugin-content-docs/src/__tests__/index.test.ts

@@ -211,6 +211,7 @@ describe('simple website', () => {
     expect(isMatch('docs/hello.js', matchPattern)).toEqual(false);
     expect(isMatch('docs/super.mdl', matchPattern)).toEqual(false);
     expect(isMatch('docs/mdx', matchPattern)).toEqual(false);
+    expect(isMatch('docs/headingAsTitle.md', matchPattern)).toEqual(true);
     expect(isMatch('sidebars.json', matchPattern)).toEqual(true);
     expect(isMatch('versioned_docs/hello.md', matchPattern)).toEqual(false);
     expect(isMatch('hello.md', matchPattern)).toEqual(false);