[bug] JSON imports broken

[niedzielski]

Thanks for the cool tool! This is a small bug report.

When I try to import any JSON such as the following:

import gamepadMapJSON from './src/input/gamepad/gamepad-map.json' assert {
  type: 'json',
}

I get an error:

✘ [ERROR] The file "src/input/gamepad/gamepad-map.json" was loaded with the "js" loader

    mod.ts:48:27:
      48 │ import gamepadMapJSON from './src/input/gamepad/gamepad-map.json' assert {
         ╵                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

  This import assertion requires the loader to be "json" instead:

    mod.ts:49:2:
      49 │   type: 'json',
         ╵   ~~~~~~~~~~~~

If I omit the assertion, Deno complains The module is a JSON module and not being imported with an import assertion. Consider adding assert { type: "json" } to the import statement.deno(no-assert-type) (and I can't seem to ignore that).

I think I should just be able to add a loader to esbuild:

  loader: {
    '.json': 'json',
  },

But that seemed to have no effect. I tried to track it down and I think esbuild_deno_loader is maybe somehow intercepting the JSON import? I'm working around this with the following JSON plugin:

    {
      name: 'json',
      setup: (build) =>
        build.onLoad({ filter: /\.json$/ }, () => ({ loader: 'json' })),
    },

In case it's helpful, the whole script looks like this:

const options: esbuild.BuildOptions = {
  sourcemap: 'linked',
  bundle: true,
  entryPoints: [input],
  format: 'esm',
  logLevel: `warning`,
  outfile: output,
  treeShaking: true,
  minify: true,
  plugins: [
    // Hack around JSON loader overrides in esbuild_deno_loader that flag type
    // assertions.
    {
      name: 'json',
      setup: (build) =>
        build.onLoad({ filter: /\.json$/ }, () => ({ loader: 'json' })),
    },
    denoPlugin({
      ...(importMap != null && { importMapURL: new URL(importMap) }),
    }) as unknown as esbuild.Plugin,
  ],
}

await esbuild.build(options)
esbuild.stop()

[lucacasonato]

Nice, esbuild fixed the behaviour of the json loader to only return JSON in the default export recently: evanw/esbuild@b1e737b. I can remove my workaround that is impacting you :)

[MrMarble]

Still broken on latest version (0.7) with esbuild 0.17.18, using the @niedzielski workaround works

[lucacasonato]

Fixed by #69