Add release-notes output (#28)

Closes: #27.

Author: nbusseneau

.gitattributes

@@ -0,0 +1,2 @@
+# Use LF as default EOL marker
+* text=auto eol=lf

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- Add a new `release-notes` output to the action containing the release notes for the newly released versions.
+
 ## [3.0.0] - 2024-04-08
 
 ### Fixed

__tests__/fixtures/empty_release/release-notes.expected.md

@@ -0,0 +1,3 @@
+### Added
+
+- Everything since the beginning!

__tests__/fixtures/first_release/release-notes.expected.md

@@ -0,0 +1,3 @@
+### Changed
+
+- Our main theme is now blue instead of red.

__tests__/fixtures/lowercase_link_reference/release-notes.expected.md

@@ -0,0 +1,3 @@
+### Changed
+
+- Our main theme is now blue instead of red.

__tests__/fixtures/standard/release-notes.expected.md

@@ -0,0 +1,3 @@
+### Changed
+
+- Our main theme is now blue instead of red.

__tests__/fixtures/tag_on_tag/release-notes.expected.md

@@ -0,0 +1,35 @@
+import getReleaseNotes from "../src/getReleaseNotes";
+import { read } from "to-vfile";
+
+interface Fixture {
+  tag: string;
+  version: string;
+  date: string;
+  genesisHash: string;
+  owner: string;
+  repo: string;
+}
+
+it.each(["empty_release", "standard", "first_release", "lowercase_link_reference", "tag_release", "tag_on_tag"])(
+  `should extract %s release-notes output`,
+  async function(testcase) {
+    const expectedChangelog = await read(
+      `./__tests__/fixtures/${testcase}/CHANGELOG.expected.md`,
+      {
+        encoding: "utf-8"
+      }
+    );
+    const release: Fixture = await import(
+      `./fixtures/${testcase}/fixture`
+    ).then(module => module.default);
+
+    const expectedReleaseNotes = await read(
+      `./__tests__/fixtures/${testcase}/release-notes.expected.md`,
+      {
+        encoding: "utf-8"
+      }
+    ).then(expected => expected.toString("utf-8"));
+    const actualReleaseNotes = getReleaseNotes(expectedChangelog, release.version);
+    expect(actualReleaseNotes).toEqual(expectedReleaseNotes);
+  }
+);

__tests__/fixtures/tag_release/release-notes.expected.md

@@ -17,6 +17,9 @@ inputs:
   changelogPath:
     description: 'The path to the changelog file. Defaults to `./CHANGELOG.md`'
     required: false
+outputs:
+  release-notes:
+    description: 'The release notes of the newly released version'
 runs:
   using: 'node20'
   main: 'dist/index.js'