Preview CHANGELOG in PR

[snebjorn]

Is your feature request related to a problem? Please describe.

I'd like to see a preview of what the CHANGELOG generated from commits will look like.

Describe the solution you'd like

Much like the pre-release (canary) section that @auto-it adds to the body of a PR. It would be neat if there would be a preview of the CHANGELOG too. That'll make it easy to spot errors or "review" the changelog :)

Example of current pre-release functionality:

<!-- GITHUB_RELEASE PR BODY: canary-version -->
<details>
  <summary>📦 Published PR as canary version: <code>Canary Versions</code></summary>
  ...
</details>
<!-- GITHUB_RELEASE PR BODY: canary-version -->

Something like this would be welcome:

<!-- GITHUB_CHANGELOG BODY -->
<details>
  <summary>📖 CHANGELOG</summary>
  ...
</details>
<!-- GITHUB_CHANGELOG BODY -->

Describe alternatives you've considered

none

Additional context

none

[snebjorn]

This seems to write the canary versions to the PR body

auto/plugins/npm/src/index.ts

Lines 1171 to 1176 in 1a84048

	return {
	newVersion: "Canary Versions",
	details: makeMonorepoInstallList(
	packageList.filter((p) => p.includes("canary"))
	),
	};

This seems to generate the changelog with the changes since last release

auto/packages/core/src/release.ts

Lines 81 to 98 in 1a84048

	/** Make the class that will generate changelogs for the project */
	@memoize()
	async makeChangelog(version?: SEMVER) {
	const project = await this.git.getProject();
	const changelog = new Changelog(this.logger, {
	owner: this.git.options.owner,
	repo: this.git.options.repo,
	baseUrl: project.html_url,
	labels: this.config.labels,
	baseBranch: this.config.baseBranch,
	prereleaseBranches: this.config.prereleaseBranches,
	});
	this.hooks.onCreateChangelog.call(changelog, version);
	changelog.loadDefaultHooks();
	return changelog;
	}

Any one got some insights on how to wire them up 🤔

[hipstersmoothie]

You could probably do this with an auto plugin pretty easily. You could hook into the canary hook and just run the changelog function in auto.