Issues when esbuild bundle rehype plugin

[Vahor]

I'm using a lib that use dynamic import of wasm and js files.

https://github.com/terrastruct/d2/blob/0b2203c107df5319380c1d72753ae8c7814324d9/d2js/js/src/index.js#L37-L42 (d2 js)

The issue here is that to do these imports the lib uses
const __dirname = dirname(fileURLToPath(import.meta.url));

and when bundled import.meta.url returns something like file:///Users/user/project/contentlayer/.cache/v0.5.4/compiled-contentlayer-config-BQHZBO35.mjs?x=1743243337285 instead of the expected file:///Users/user/project/node_modules/@terrastruct/d2/dist/node-esm/index.js. with this, every import fails.

The config bundle happens here:

contentlayer2/packages/@contentlayer/core/src/getConfig/index.ts

Lines 68 to 84 in 37c800c

	esbuild.makeAndSubscribe({
	entryPoints: [configPath],
	entryNames: '[name]-[hash]',
	outfile: outfilePath,
	sourcemap: true,
	platform: 'node',
	target: 'es2020',
	format: 'esm',
	// needed in case models are co-located with React components
	jsx: 'transform',
	bundle: true,
	logLevel: 'silent',
	metafile: true,
	absWorkingDir: cwd,
	plugins: [contentlayerGenPlugin(), makeAllPackagesExternalPlugin(configPath)],
	}),
	S.mapEffectEitherRight((result) => getConfigFromResult({ result, configPath })),

The fix would be to allow a custom list of external modules in the esbuild makeAndSubscribe call.
external: ["my-lib"],

an idea would be to pass a custom esbuild config param in the NextPluginOptions in

contentlayer2/packages/next-contentlayer/src/plugin.ts

Lines 32 to 67 in 37c800c

	const runContentlayerBuild = async ({ configPath }: NextPluginOptions) => {
	if (contentlayerInitialized) return
	contentlayerInitialized = true
	await pipe(
	core.getConfig({ configPath }),
	T.chain((config) => core.generateDotpkg({ config, verbose: false })),
	T.tap(core.logGenerateInfo),
	OT.withSpan('next-contentlayer:runContentlayerBuild'),
	runMain,
	)
	}
	const runMain = core.runMain({ tracingServiceName: 'next-contentlayer', verbose: process.env.CL_DEBUG !== undefined })
	export const runBeforeWebpackCompile = async ({
	mode,
	pluginOptions,
	devServerStartedRef,
	}: {
	mode: WebpackOptionsNormalized['mode']
	pluginOptions: NextPluginOptions
	devServerStartedRef: { current: boolean }
	}) => {
	const isNextDev = mode === 'development'
	const isBuild = mode === 'production'
	const { configPath } = pluginOptions
	if (isBuild) {
	checkConstraints()
	await runContentlayerBuild({ configPath })
	} else if (isNextDev && !devServerStartedRef.current) {
	devServerStartedRef.current = true
	// TODO also block here until first Contentlayer run is complete
	runContentlayerDev({ configPath })

Repro:

• https://github.com/Vahor/contentlayer2-bundle-d2-repro
• commits:
  1. First commit is a nextjs init app;
  2. 2nd is to introduce a similar behavior as a rehype plugin using d2
  3. 3rd is a patch to show that using external option for esbuild fixes the issue (the only change is external: ["@terrastruct/d2"],)

[timlrx]

If you are using mdx, have you tried modifying esbuildOptions in the mdx property in makeSource?

[Vahor]

Like this ?

mdx: {
  rehypePlugins: [superRehypePlugin],
  esbuildOptions: (config) => ({
    ...config,
    external: ["my-lib"],
  }),
},

This did not help for the issue.

From what I read in the code, this option is used to build the mdx from the content files.
My issue is related to the .cache build of the content layer config file.

[timlrx]

I see, yes in that case it seems like we would need to allow the user to modify esbuildOption in pluginOptions before passing it over. We can make that change for the next-contentlayer plugin as well as the CLI to be consistent. Would you be interested in making a PR to fix the issue?

[Vahor]

I can try yes 👍