`injectScript` never resolves in MV2

[nines75]

Describe the bug

I used injectScript according to the documentation below. While it resolves correctly in MV3, it never resolves in MV2.

https://wxt.dev/guide/essentials/content-scripts.html#isolated-world-vs-main-world

Reproduction

reproduction.zip

Steps to reproduce

1. Run pnpm install
2. Run pnpm dev:firefox
3. Load the extension into Firefox.
4. Navigate to https://www.google.com/.
5. Open the developer tools console and verify that Done! is not logged.

System Info

System:
    OS: Linux 6.6 Ubuntu 24.04.4 LTS 24.04.4 LTS (Noble Numbat)
    CPU: (24) x64 13th Gen Intel(R) Core(TM) i7-13700F
    Memory: 20.96 GB / 23.38 GB
    Container: Yes
    Shell: 5.2.21 - /bin/bash
  Binaries:
    Node: 24.14.0 - /home/nines/.volta/tools/image/node/24.14.0/bin/node
    npm: 11.11.0 - /home/nines/.volta/tools/image/npm/11.11.0/bin/npm
    pnpm: 10.30.3 - /home/nines/.volta/tools/image/pnpm/10.30.3/bin/pnpm
  npmPackages:
    wxt: ^0.20.18 => 0.20.18

Used Package Manager

pnpm

Validations

• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Check that this is a concrete bug. For Q&A open a GitHub Discussion or join our Discord Chat Server.
• The provided reproduction is a minimal reproducible example of the bug.

[PatrykKuniczak]

Very strange BUG

[PatrykKuniczak]

I've been trying to solve it, stay tuned 😄

[PatrykKuniczak]

I've figured out it yesterday, but today i've tested it and add tests and example in #2233, i hope this will work also for you.
If you @nines75 Are able to try #2232, i'll be glad 😄

[nines75]

I have tested it on Firefox MV2 and confirmed that it works correctly. Thank you.
However, it seems it would be better to call makeLoadedPromise before appending the script. This is because there is a possibility that the event handler hasn't been registered yet when the script executes.

[PatrykKuniczak]

@nines75 I'll do it, thanks ❤️