vite v6.0.7 breaks vite-plugin-top-level-await

[ocavue]

Describe the bug

After updating vite from v6.0.6 to v6.0.7, vite-plugin-top-level-await doesn't work anymore. vite-plugin-top-level-await is required by vite-plugin-wasm and many other wasm packages.

Reproduction

https://github.com/issueset/vite-plugin-top-level-await-regression

Steps to reproduce

Here is a minimal example to show the error with vite v6.0.7:

$ git clone https://github.com/issueset/vite-plugin-top-level-await-regression --branch 607 607

$ cd 607

$ pnpm install
+ vite 6.0.7
+ vite-plugin-top-level-await 1.4.4

$ pnpm run build

x Build failed in 44ms
error during build:
[vite:esbuild-transpile] Transform failed with 1 error:
assets/index-!~{001}~.js:45:0: ERROR: Top-level await is not available in the configured target environment ("chrome87", "edge88", "es2020", "firefox78", "safari14" + 2 overrides)

Top-level await is not available in the configured target environment ("chrome87", "edge88", "es2020", "firefox78", "safari14" + 2 overrides)
43 |  console.log("START_TOP_LEVEL_AWAIT");
44 |  let number1 = Math.random();
45 |  await new Promise((resolve) => setTimeout(resolve, 1000));
   |  ^
46 |  let number2 = Math.random();
47 |  console.log("END_TOP_LEVEL_AWAIT");

Here is the same example with vite v6.0.6, which works fine:

$ git clone https://github.com/issueset/vite-plugin-top-level-await-regression --branch 606 606

$ cd 606 

$ pnpm install
+ vite 6.0.6
+ vite-plugin-top-level-await 1.4.4

$ pnpm run build
✓ built in 58ms

System Info

System:
    OS: macOS 15.1.1
    CPU: (8) arm64 Apple M2
    Memory: 66.14 MB / 24.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 20.18.1 - /opt/homebrew/opt/node@20/bin/node
    Yarn: 1.22.21 - /opt/homebrew/opt/node@18/bin/yarn
    npm: 10.8.2 - /opt/homebrew/opt/node@20/bin/npm
    pnpm: 8.15.9 - /opt/homebrew/opt/node@18/bin/pnpm
    bun: 1.1.26 - /opt/homebrew/bin/bun
  Browsers:
    Brave Browser: 122.1.63.169
    Chrome: 131.0.6778.264
    Chrome Canary: 134.0.6944.0
    Safari: 18.1.1
    Safari Technology Preview: 18.2
  npmPackages:
    vite: 6.0.7 => 6.0.7

Used Package Manager

pnpm

Logs

No response

Validations

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• 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.
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• The provided reproduction is a minimal reproducible example of the bug.

[hi-ogawa]

vite-plugin-top-level-await is mutating config.build.target = 'esnext' during configResolved() hook https://github.com/Menci/vite-plugin-top-level-await/blob/ae432b6823d6608b0de8c607bf14c3025c76e80a/src/index.ts#L56-L60 and this is not a supported usage, which then got broken by the change like #19025

I think vite-plugin-top-level-await can use config() hook instead to override config properly.

        config(config, env) {
            if (env.command === 'build') {
                buildTarget = config.build.target;
                config.build.target = "esnext";
            }
        },