(fix) bundle-size: reuse ts helper functions from tslib instead of in…

[xcariba]

What it does

Fixes #13345

Reuses ts helper functions from tslib instead of inlining

How to test

Build master, check its size, build this branch, size will be smaller

Follow-ups

none

Review checklist

• As an author, I have thoroughly tested my changes and carefully followed the review guidelines

Reminder for reviewers

• As a reviewer, I agree to behave in accordance with the review guidelines

[msujew]

Thanks for the contribution. The CLI actually also generates code that depends on tslib. Any project that just pulls @theia/cli without pulling @theia/core will break with this change. So you need to add the dependency there as well.

[msujew]

@xcariba FYI, it's not only @theia/cli, but all packages under dev-packages which need this as well. In every one of them is a require('tslib') call in the generated code now.

Alternatively, we could think about only using this in a few selected packages that are guaranteed to get pulled like @theia/core and @theia/application-package.

[sdirix]

Alternatively, we could think about only using this in a few selected packages that are guaranteed to get pulled like @theia/core and @theia/application-package.

Personally I would prefer having a clean dependency in each package. The additional effort is really minimal, because if we need to update all versions then a simple search-replace will do.

I'm not sure whether it's of practical relevance but not declaring the dependency in each package could lead to weird errors. For example a "random" tslib version being resolved for the ones which don't declare, potentially leading to errors, especially in downstream projects.

[msujew]

@sdirix Yeah, I can see that. I think the maintenance overhead is negligible and it probably makes sense to prevent weird dependency resolving errors.

[Alexander-Taran]

@sdirix @msujew
having it in dependencies is relevant only for cases when a package will get bundled or executed outside of scope where @theia/cli is pulled.

In case of /packages/ we want to ensure that tslib is present in node_modules at the time of bunlding the app.
Do dev-packages have a story being pulled on their own?
#13345 (comment)

[sdirix]

Hi @Alexander-Taran,

The error case described above is also relevant for the dev-packages. Dev packages like @theia/application-manager and @theia/application-package are consumed by @theia/cli and are therefore part of the node_modules of all downstream projects.

If only @theia/cli has a dependency to tslib, then only for the @theia/cli code itself it's guaranteed to consume the correct version of tslib. Once the code execution enters @theia/application-manager an incompatible tslib coming in from the downstream project might be consumed leading to errors.

Even if that would not be a use case: All published packages should have the correct set of dependencies as we can never predict what consumers will do with them.

[Alexander-Taran]

@sdirix that's exactly what I meant in my comment to my original PR. That we (our team) don't know weather dev-packages need this dependency. And if so - which ones do.

[msujew]

@Alexander-Taran Once you start setting the importHelper property to true, every package that is affected by this setting should have the tslib dependency. Otherwise, one might into dependency resolution errors (either during bundling or runtime).

[Alexander-Taran]

@msujew @sdirix we've updated dev-packages also. (-:

[Alexander-Taran]

💤

[msujew]

Looks good to me. Can you rebase so we can merge this?

[Alexander-Taran]

Looks good to me. Can you rebase so we can merge this?

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