Tracking for 67 as it will probably deserve a mention in out developers release notes.

This has been enabled in nightly since the end of January and there haven't been any major bugs found. (Bug 1529203 was discovered but this was already present). What do you think about enabling this by default and letting it ride the trains, to ship in 67?

Please send email about this to dev.platform

https://hg.mozilla.org/mozilla-central/rev/6ce854f480d6

Hi, maybe I'm doing something wrong, but I'm not able to import a module in a webextension content script via the dynamic import. I also tried this version which works in chrome: https://github.com/otiai10/chrome-extension-es6-import

By trying it myself I got the following errors:
Error: TelemetryStopwatch: key "WEBEXT_CONTENT_SCRIPT_INJECTION_MS" was already initialized ExtensionTelemetry.jsm:106:31
Error: TelemetryStopwatch: key "WEBEXT_CONTENT_SCRIPT_INJECTION_MS_BY_ADDONID" was already initialized ExtensionTelemetry.jsm:110:41
Error: TelemetryStopwatch: requesting elapsed time for nonexisting stopwatch. Histogram: "WEBEXT_CONTENT_SCRIPT_INJECTION_MS", key: "" ExtensionTelemetry.jsm:106:31
Error: TelemetryStopwatch: requesting elapsed time for nonexisting stopwatch. Histogram: "WEBEXT_CONTENT_SCRIPT_INJECTION_MS_BY_ADDONID"

However the provided add-on above does not produce any errors, but still doesn't log anything to the console.

Firefox Developer Edition 66.0b14 (64-Bit), Linux with enabled javascript.options.dynamicImport pref;

(In reply to robbendebiene from comment #6)

I've filed bug 1536094 for this.

Note to MDN writers:

We've already added a note about this to the Fx67 rel notes:
https://developer.mozilla.org/en-US/docs/Mozilla/Firefox/Releases/67#JavaScript

It looks like the BCD for import() could do with being updated

I also think it'd make sense to include a tutorial somewhere (in the JS guide?) explaining JS module import/export, how to use them, etc.

BCD updated for this bug: https://github.com/mdn/browser-compat-data/pull/4110

I've also finished rabbit-holing on my guide to JS modules:

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules

With that, I think the docs here and now complete. Feel free to give me a shout if you notice anything that isn't quite right.