Doug Parker 🕸️<p>Great post on <a href="https://techhub.social/tags/ClosureCompiler" class="mention hashtag" rel="tag">#<span>ClosureCompiler</span></a>, it's history at <a href="https://techhub.social/tags/Google" class="mention hashtag" rel="tag">#<span>Google</span></a> and how it evolved compared to <a href="https://techhub.social/tags/TypeScript" class="mention hashtag" rel="tag">#<span>TypeScript</span></a>.</p><p><a href="https://effectivetypescript.com/2023/09/27/closure-compiler/" target="_blank" rel="nofollow noopener" translate="no"><span class="invisible">https://</span><span class="ellipsis">effectivetypescript.com/2023/0</span><span class="invisible">9/27/closure-compiler/</span></a></p><p>I can help with one of the last points:</p><p>> True to form, this tool [tsickle] is open source but pretty inscrutable to an outsider. It may be used by Angular but I couldn't tell.</p><p>I can confirm that Angular does *not* run `tsickle` or Closure in user projects with `ng build`. There was an experiment some years ago where we tried this to see if we could improve bundle sizes, but found that asking users to write Closure-optimizable code was too difficult and hard to justify outside Google. As a result, we never ran this in prod.</p><p>I believe we do technically run `tsickle` in Angular GitHub repositories, as we have a unique build system setup with <a href="https://techhub.social/tags/Bazel" class="mention hashtag" rel="tag">#<span>Bazel</span></a> and <a href="https://techhub.social/tags/rules_nodejs" class="mention hashtag" rel="tag">#<span>rules_nodejs</span></a>. If you've ever contributed to Angular, you probably ran `tsickle`. We've been trying to remove this dependency, but I don't think it's happened yet.</p>