Angular, once compiled, doesn’t provide compatibility between different patch levels?

[michaelhunziker]

For which library do you need help?

module-federation

Question

Hi everyone,

I just read this #645 (comment) from @rainerhahnekamp mentioning that Angular, once compiled, doesn’t provide compatibility between different patch levels.

Am I understanding correctly that we should use fixed versions (no ^ or ~) in all our projects?

shell package.json:
"@angular/common": "20.3.3",
"@angular/core": "20.3.3"

microfrontend1 package.json:
"@angular/common": "20.3.3",
"@angular/core": "20.3.3"

microfrontend2 package.json:
"@angular/common": "20.3.3",
"@angular/core": "20.3.3"

microfrontend3 package.json:
"@angular/common": "^20.3.3", // PROBLEM! in package-lock.json we could e.g. have 20.3.15!
"@angular/core": "^20.3.3"

We have multiple teams working on multiple microfrontends, so keeping every version of the shared libraries perfectly aligned at the patch level would require a significant amount of coordination.

Thanks for the clarification!

Cheers,
Michael

[rainerhahnekamp]

@michaelhunziker, yes, that's still true as of today. That being said, strictVersion is enabled by default and will throw a runtime error.

There are some inofficial signs from the Angular team to loosen up that restriction and maybe only break on a minor level.

One also has to say, that breaking changes on the instruction set level don't happen that often, but if...they can do it on a patch level.

[michaelhunziker]

Thanks for the quick answer, @rainerhahnekamp!

Has the fact that Angular does not provide patch‑level compatibility for compiled code always been true since the beginning of @angular-architects/module-federation?

Regarding strictVersion and my example above: as far as I understand, only the package.json versions are compared. But as you can see, microfrontend3 actually has version 20.3.15 installed (according to its package-lock.json). Would this also cause a runtime error?

[rainerhahnekamp]

🤷‍♂️as far as I know that check happens during runtime. So it counts what you really have

[manfredsteyer]

What @rainerhahnekamp says!

If there is the chance that you even have different patch versions, you should really prepare for a multi-version scenario (wrapping components into web components, for instance)