Invalid OnResolveArgs.Importer for stdin in >= 0.8.21

[bep]

Before 0.8.21 we got the value stdin which is a constant I know how to handle.

After 0.8.21 we get what looks like an absolute filename, but it points to a file that does not exist -- but most importantly I don't know the origin of it to resolve imports relative to it.

gohugoio/hugo#8189

[evanw]

I've got some tests that cover various cases with stdin here:

esbuild/scripts/plugin-tests.js

Lines 746 to 880 in ad97902

	async stdinImporter({ esbuild, testDir }) {
	const output = path.join(testDir, 'out.js')
	await esbuild.build({
	stdin: {
	contents: `import x from "plugin"; export default x`,
	sourcefile: 'stdin-sourcefile',
	},
	bundle: true, outfile: output, format: 'cjs', plugins: [{
	name: 'name',
	setup(build) {
	build.onResolve({ filter: /^plugin$/ }, args => {
	assert.strictEqual(args.namespace, '')
	assert.strictEqual(args.importer, 'stdin-sourcefile')
	assert.strictEqual(args.resolveDir, '')
	assert.strictEqual(args.path, 'plugin')
	return { path: args.path, namespace: 'worked' }
	})
	build.onLoad({ filter: /.*/, namespace: 'worked' }, () => {
	return { contents: `export default 123` }
	})
	},
	}],
	})
	const result = require(output)
	assert.strictEqual(result.default, 123)
	},
	async stdinImporterResolveDir({ esbuild, testDir }) {
	const output = path.join(testDir, 'out.js')
	await esbuild.build({
	stdin: {
	contents: `import x from "plugin"; export default x`,
	sourcefile: 'stdin-sourcefile',
	resolveDir: testDir,
	},
	bundle: true, outfile: output, format: 'cjs', plugins: [{
	name: 'name',
	setup(build) {
	build.onResolve({ filter: /^plugin$/ }, args => {
	assert.strictEqual(args.namespace, 'file')
	assert.strictEqual(args.importer, path.join(testDir, 'stdin-sourcefile'))
	assert.strictEqual(args.resolveDir, testDir)
	assert.strictEqual(args.path, 'plugin')
	return { path: args.path, namespace: 'worked' }
	})
	build.onLoad({ filter: /.*/, namespace: 'worked' }, () => {
	return { contents: `export default 123` }
	})
	},
	}],
	})
	const result = require(output)
	assert.strictEqual(result.default, 123)
	},
	async stdinAbsoluteImporterResolveDir({ esbuild, testDir }) {
	const output = path.join(testDir, 'out.js')
	await esbuild.build({
	stdin: {
	contents: `import x from "plugin"; export default x`,
	sourcefile: path.join(testDir, 'stdin-sourcefile'),
	resolveDir: testDir,
	},
	bundle: true, outfile: output, format: 'cjs', plugins: [{
	name: 'name',
	setup(build) {
	build.onResolve({ filter: /^plugin$/ }, args => {
	assert.strictEqual(args.namespace, 'file')
	assert.strictEqual(args.importer, path.join(testDir, 'stdin-sourcefile'))
	assert.strictEqual(args.resolveDir, testDir)
	assert.strictEqual(args.path, 'plugin')
	return { path: args.path, namespace: 'worked' }
	})
	build.onLoad({ filter: /.*/, namespace: 'worked' }, () => {
	return { contents: `export default 123` }
	})
	},
	}],
	})
	const result = require(output)
	assert.strictEqual(result.default, 123)
	},
	async stdinRelative({ esbuild, testDir }) {
	const output = path.join(testDir, 'out.js')
	await esbuild.build({
	stdin: {
	contents: `import x from "./stdinRelative.js"; export default x`,
	},
	bundle: true, outfile: output, format: 'cjs', plugins: [{
	name: 'name',
	setup(build) {
	build.onResolve({ filter: /.*/ }, args => {
	assert.strictEqual(args.namespace, '')
	assert.strictEqual(args.importer, '<stdin>')
	assert.strictEqual(args.resolveDir, '')
	assert.strictEqual(args.path, './stdinRelative.js')
	return { path: args.path, namespace: 'worked' }
	})
	build.onLoad({ filter: /.*/, namespace: 'worked' }, () => {
	return { contents: `export default 123` }
	})
	},
	}],
	})
	const result = require(output)
	assert.strictEqual(result.default, 123)
	},
	async stdinRelativeResolveDir({ esbuild, testDir }) {
	const output = path.join(testDir, 'out', 'out.js')
	await esbuild.build({
	stdin: {
	contents: `import x from "./stdinRelative.js"; export default x`,
	resolveDir: testDir,
	},
	bundle: true, outfile: output, format: 'cjs', plugins: [{
	name: 'name',
	setup(build) {
	build.onResolve({ filter: /.*/ }, args => {
	assert.strictEqual(args.namespace, '')
	assert.strictEqual(args.importer, '<stdin>')
	assert.strictEqual(args.resolveDir, testDir)
	assert.strictEqual(args.path, './stdinRelative.js')
	return { path: args.path, namespace: 'worked' }
	})
	build.onLoad({ filter: /.*/, namespace: 'worked' }, () => {
	return { contents: `export default 123` }
	})
	},
	}],
	})
	const result = require(output)
	assert.strictEqual(result.default, 123)
	},

There you can see what various combinations of Stdin options and the resulting Importer are. It looks like if you pass both a ResolveDir and a Sourcefile, the importer will now be the Sourcefile path resolved relative to the ResolveDir. The behavior is somewhat arbitrary but I probably did it that way so that it's consistent with how the importer for other files behave. Sorry about the breakage–I don't think I had test coverage for these cases before that change.

It looks like you should be able to get <stdin> back by not passing the Sourcefile option to Stdin. I think that should fix your use case unless you needed the Sourcefile for something. Alternatively, you can also avoid using Stdin altogether and just provide the contents of the entry point file with a plugin. An example of doing that is here: #720 (comment).

Unrelated: While I have your attention, I believe there's also a bug with Hugo's use of esbuild's API that causes Hugo to crash with a null pointer error. Details are here. It seems like an easy fix.

[bep]

Thanks; I will have a look at it. The nilpointer is fixed (I'm pretty sure ...)

[bep]

Yes, that works, and I guess the current behaviour makes sense. Closing.