1808360 - Add error message for importmap with src attribute

Status: RESOLVED FIXED

(Core :: JavaScript Engine, task, P3)

Description

[Nicolas Chevobbe [:nchevobbe]]

Steps to reproduce

1. Open a tab on https://ffx-external-import-map.glitch.me/
2. Open the console

Result

As I was testing out importmap, I tried declaring as we do for external script:

    <script type="importmap" src="map.json"></script>

In such case, I do get an error on the console as the importmap isn't loaded, and thus the import fails

Uncaught TypeError: The specifier “square” was a bare specifier, but was not remapped to anything. Relative module specifiers must start with “./”, “../” or “/”. module.js:1:27

But I don't get any error about the importmap being invalid (unlike in Bug 1808357).
It would be nice to have an error (or warning) message to indicate that the importmap can't be specified in an external file and should be inlined

Comment 1

[Yoshi Cheng-Hao Huang [:allstars.chh][:allstarschh][:yoshi]]

Per spec, the onerror handler of the script tag will be called if it's external script with type is "importmap".

See
https://html.spec.whatwg.org/multipage/scripting.html#prepare-the-script-element
Step 30.1

Comment 2

[Nicolas Chevobbe [:nchevobbe]]

(In reply to Yoshi Cheng-Hao Huang [:allstars.chh][:allstarschh][:yoshi] from comment #1)

Per spec, the onerror handler of the script tag will be called if it's external script with type is "importmap".

See
https://html.spec.whatwg.org/multipage/scripting.html#prepare-the-script-element
Step 30.1

That's good to know but do require people to know about the onerror handler too. Having a warning message would be a nice way to reduce frustration for users so they don't have to search around what's going on

Comment 3

[Yoshi Cheng-Hao Huang [:allstars.chh][:allstarschh][:yoshi]]

I will try to dump some error message in console.

Comment 4

[Yoshi Cheng-Hao Huang [:allstars.chh][:allstarschh][:yoshi]]

Attachment: Bug 1808360 - Add error message for external import maps.

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/302bffceb24a
Add error message for external import maps. r=jonco,flod

Comment 6

[Noemi Erli[:noemi_erli]]

https://hg.mozilla.org/mozilla-central/rev/302bffceb24a