fix #899: cross-chunk import paths

CHANGELOG.md

@@ -37,6 +37,10 @@
     }
     ```
 
+* Fix cross-chunk import paths ([#899](https://github.com/evanw/esbuild/issues/899))
+
+    This release fixes an issue with the `--chunk-names=` feature where import paths in between two different automatically-generated code splitting chunks were relative to the output directory instead of relative to the importing chunk. This caused an import failure with the imported chunk if the chunk names setting was configured to put the chunks into a subdirectory. This bug has been fixed.
+
 ## 0.8.53
 
 * Support chunk and asset file name templates ([#733](https://github.com/evanw/esbuild/issues/733), [#888](https://github.com/evanw/esbuild/issues/888))

internal/bundler/linker.go

@@ -65,6 +65,10 @@ type linkerContext struct {
 	files       []file
 	hasErrors   bool
 
+	// This is the relative path for automatically-generated code splitting chunks
+	// relative to the output directory
+	generatedChunkRelDir string
+
 	// This helps avoid an infinite loop when matching imports to exports
 	cycleDetector []importTracker
 
@@ -349,6 +353,15 @@ func newLinkerContext(
 		symbols:           js_ast.NewSymbolMap(len(files)),
 		reachableFiles:    reachableFiles,
 		dataForSourceMaps: dataForSourceMaps,
+
+		// Note: This contains placeholders instead of what the placeholders are
+		// substituted with. That should be fine though because this should only
+		// ever be used for figuring out how many "../" to add to a relative path
+		// from a chunk whose final path hasn't been calculated yet to a chunk
+		// whose final path has already been calculated. That and placeholders are
+		// never substituted with something containing a "/" so substitution should
+		// never change the "../" count.
+		generatedChunkRelDir: fs.Dir(config.TemplateToString(options.ChunkPathTemplate)),
 	}
 
 	// Clone various things since we may mutate them later
@@ -2755,6 +2768,7 @@ func (c *linkerContext) computeChunks() []chunkInfo {
 				if !ok {
 					chunk.entryBits = partMeta.entryBits
 					chunk.filesWithPartsInChunk = make(map[uint32]bool)
+					chunk.relDir = c.generatedChunkRelDir
 					chunk.chunkRepr = &chunkReprJS{}
 					chunks[key] = chunk
 				}
@@ -2771,6 +2785,7 @@ func (c *linkerContext) computeChunks() []chunkInfo {
 			if !ok {
 				chunk.entryBits = file.entryBits
 				chunk.filesWithPartsInChunk = make(map[uint32]bool)
+				chunk.relDir = c.generatedChunkRelDir
 				chunk.chunkRepr = &chunkReprJS{}
 				chunks[key] = chunk
 			}

scripts/js-api-tests.js

@@ -1282,6 +1282,70 @@ export {
     assert.strictEqual(value.outputFiles[2].path, path.join(outdir, chunk))
   },
 
+  async splittingWithChunkPathAndCrossChunkImportsIssue899({ esbuild, testDir }) {
+    const entry1 = path.join(testDir, 'src', 'entry1.js')
+    const entry2 = path.join(testDir, 'src', 'entry2.js')
+    const entry3 = path.join(testDir, 'src', 'entry3.js')
+    const shared1 = path.join(testDir, 'src', 'shared1.js')
+    const shared2 = path.join(testDir, 'src', 'shared2.js')
+    const shared3 = path.join(testDir, 'src', 'shared3.js')
+    await mkdirAsync(path.join(testDir, 'src')).catch(x => x)
+    await writeFileAsync(entry1, `
+      import { shared1 } from './shared1';
+      import { shared2 } from './shared2';
+      export default async function() {
+        return shared1() + shared2();
+      }
+    `)
+    await writeFileAsync(entry2, `
+      import { shared2 } from './shared2';
+      import { shared3 } from './shared3';
+      export default async function() {
+        return shared2() + shared3();
+      }
+    `)
+    await writeFileAsync(entry3, `
+      import { shared3 } from './shared3';
+      import { shared1 } from './shared1';
+      export default async function() {
+        return shared3() + shared1();
+      }
+    `)
+    await writeFileAsync(shared1, `
+      import { shared2 } from './shared2';
+      export function shared1() {
+        return shared2().replace('2', '1');
+      }
+    `)
+    await writeFileAsync(shared2, `
+      import { shared3 } from './shared3'
+      export function shared2() {
+        return 'shared2';
+      }
+    `)
+    await writeFileAsync(shared3, `
+      export function shared3() {
+        return 'shared3';
+      }
+    `)
+    const outdir = path.join(testDir, 'out')
+    await esbuild.build({
+      entryPoints: [entry1, entry2, entry3],
+      bundle: true,
+      outdir,
+      format: 'esm',
+      splitting: true,
+      outExtension: { '.js': '.mjs' },
+      chunkNames: 'chunks/[hash]/[name]',
+    })
+    const result1 = await import(path.join(outdir, 'entry1.mjs'))
+    const result2 = await import(path.join(outdir, 'entry2.mjs'))
+    const result3 = await import(path.join(outdir, 'entry3.mjs'))
+    assert.strictEqual(await result1.default(), 'shared1shared2');
+    assert.strictEqual(await result2.default(), 'shared2shared3');
+    assert.strictEqual(await result3.default(), 'shared3shared1');
+  },
+
   async stdinStdoutBundle({ esbuild, testDir }) {
     const auxiliary = path.join(testDir, 'auxiliary.js')
     await writeFileAsync(auxiliary, 'export default 123')