Cover multiple import maps #37739
Cover multiple import maps #37739
Conversation
yoavweiss
requested review from
chrisdavidmills
and removed request for
a team
github-actions
bot
added
Content:HTML
![github-actions[bot]](https://avatars.githubusercontent.com/in/15368?s=60&v=4){kind=small}
|
Preview URLs External URLs (1)URL:
(comment last updated: 2025-01-28 16:13:52) |
There was a problem hiding this comment.
Hi @yoavweiss!
Thanks for the awesome work here in getting this documented. I have a few horrible nitpicky comments for you to consider (too much coffee, maybe), but I think this is going in the right direction.
|
|
||
| <aside>This is supported is the latest versions of some browsers. In non-supporting browsers, a [polyfill](https://github.com/guybedford/es-module-shims) can be used to avoid issues related to module resolution.</aside> | ||
|
|
||
| Internally, browsers maintain a single global import map representation. |
There was a problem hiding this comment.
There seems to be no explanation here of how the browser handles multiple import maps. I can guess from the heading that they are merged in some way into the single global import map representation when you include them in a document, but it is not explicitly covered.
There was a problem hiding this comment.
I merged (pun not intended) this sentence and the next to try and make that clearer. Let me know if more details are needed.
There was a problem hiding this comment.
This is much better than it was. It still feels to me like paragraph one needs a sentence at the end along the lines of "When multiple import maps are included in a document, the browser does blah..."
There was a problem hiding this comment.
My example probably sounds wrong, but, you get the idea ;-)
There was a problem hiding this comment.
Rephrased. Let me know if that works
|
|
||
| When an import map is registered, its contents are merged into the global import map. | ||
|
|
||
| Module specifiers in the registered map that were already resolved before are dropped. Future resolution of these specifiers will provide the same results as their previous resolution. |
There was a problem hiding this comment.
The last two sentences make sense, but I do have a few comments for you to consider:
- "Future resolution of these specifiers will provide the same results as their previous resolution." seems to contradict the "are dropped" assertion — it sounds like "are dropped" might be saying that that they are ignored, whereas the first quoted sentence sounds like they are evaluated but provide the same result. It would be good to be clearer about what's going on.
- "prevails" makes sense, but seems like a slightly weird word to use in a tech context. I had to read it a few times to figure out what you were saying, and I wonder how understandable it is to the majority of readers who have English as an additional language. You could say something like "previous mapping continues to take effect", or maybe even something simpler like "previous mapping wins"?
- I think this stuff would be easier to understand if you described a scenario where you have a first import map that contains mappings A and B, then a second map containing mappings A and C. When the first one is evaluated, A and B are added to the global map. When the second one is evaluated, C is added, but A is ignored because it was already previously added, etc. At the moment, you can guess that you are talking about specifiers that were already included in previous import maps, but it would be helpful to make this explicit.
There was a problem hiding this comment.
There's a series of examples after the processing model in https://html.spec.whatwg.org/#merge-module-specifier-maps. Do you think it would make sense to bring in some of those here to make the behavior clearer?
There was a problem hiding this comment.
Yes, it would be good to include a couple in MDN. I would suggest including an example and some more explanation after paragraph 2, and an example and some more explanation after paragraph 3, to explain and demonstrate each case.
There was a problem hiding this comment.
Added examples. PTAL?
There was a problem hiding this comment.
Looking much better @yoavweiss, definitely getting there! Couple more comments for you to sift through.
…nto multiple_import_maps
yoavweiss
requested review from
sideshowbarker and
estelle
and removed request for
a team
github-actions
bot
added
Content:CSS
|
Looks like your branch is messed up. You need to do a rebase or carry your changes to a new branch. |
github-actions
bot
added
size/m
Fixed. |
|
Also: you would want to update https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules#importing_modules_using_import_maps as well |
Done by removing the "only one" mention there. Let me know if you think I need to explicitly say there that multiple maps can be supported. |
There was a problem hiding this comment.
Thanks again @yoavweiss; I am pretty happy with this now.
I made a few small grammatical tweaks to clean it up a bit, and now I think we are ready to merge.
|
@yoavweiss did you end up submitting a PR to update the BCD for the page? If not, I'm happy to do that. |
|
@chrisdavidmills - I did not. I can do that on Friday, unless you beat me to it :) |
See mdn/browser-compat-data#25801 ;-) |
Thanks!! |
Description
This PR aims to cover the "multiple import maps" HTML change
Motivation
Current import map language is misleading, at least in ToT Chromium/WebKit.
Additional details
Related issues and pull requests
Fixes mdn/mdn#622