Preview CHANGELOG in PR

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

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 🤔

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.

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

	/** 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;
	}