fix #4053: reordering of .tsx in node_modules

CHANGELOG.md

@@ -162,6 +162,10 @@
 
     With this release, you can now use BigInt literals as define values, such as with `--define:FOO=123n`. Previously trying to do this resulted in a syntax error.
 
+* Fix a bug with resolve extensions in `node_modules` ([#4053](/~https://github.com/evanw/esbuild/issues/4053))
+
+    The `--resolve-extensions=` option lets you specify the order in which to try resolving implicit file extensions. For complicated reasons, esbuild reorders TypeScript file extensions after JavaScript ones inside of `node_modules` so that JavaScript source code is always preferred to TypeScript source code inside of dependencies. However, this reordering had a bug that could accidentally change the relative order of TypeScript file extensions if one of them was a prefix of the other. That bug has been fixed in this release. You can see the issue for details.
+
 * Emit `/* @__KEY__ */` for string literals derived from property names ([#4034](/~https://github.com/evanw/esbuild/issues/4034))
 
     Property name mangling is an advanced feature that shortens certain property names for better minification (I say "advanced feature" because it's very easy to break your code with it). Sometimes you need to store a property name in a string, such as `obj.get('foo')` instead of `obj.foo`. JavaScript minifiers such as esbuild and [Terser](https://terser.org/) have a convention where a `/* @__KEY__ */` comment before the string makes it behave like a property name. So `obj.get(/* @__KEY__ */ 'foo')` allows the contents of the string `'foo'` to be shortened.

internal/bundler/bundler.go

@@ -190,7 +190,7 @@ func parseFile(args parseArgs) {
 
 	// The special "default" loader determines the loader from the file path
 	if loader == config.LoaderDefault {
-		loader = loaderFromFileExtension(args.options.ExtensionToLoader, base+ext)
+		loader = config.LoaderFromFileExtension(args.options.ExtensionToLoader, base+ext)
 	}
 
 	// Reject unsupported import attributes when the loader isn't "copy" (since
@@ -1199,30 +1199,6 @@ func runOnLoadPlugins(
 	return loaderPluginResult{loader: config.LoaderNone}, true
 }
 
-func loaderFromFileExtension(extensionToLoader map[string]config.Loader, base string) config.Loader {
-	// Pick the loader with the longest matching extension. So if there's an
-	// extension for ".css" and for ".module.css", we want to match the one for
-	// ".module.css" before the one for ".css".
-	if i := strings.IndexByte(base, '.'); i != -1 {
-		for {
-			if loader, ok := extensionToLoader[base[i:]]; ok {
-				return loader
-			}
-			base = base[i+1:]
-			i = strings.IndexByte(base, '.')
-			if i == -1 {
-				break
-			}
-		}
-	} else {
-		// If there's no extension, explicitly check for an extensionless loader
-		if loader, ok := extensionToLoader[""]; ok {
-			return loader
-		}
-	}
-	return config.LoaderNone
-}
-
 // Identify the path by its lowercase absolute path name with Windows-specific
 // slashes substituted for standard slashes. This should hopefully avoid path
 // issues on Windows where multiple different paths can refer to the same

internal/bundler_tests/bundler_default_test.go

@@ -9206,3 +9206,43 @@ func TestSourceIdentifierNameIndexMultipleEntry(t *testing.T) {
 		},
 	})
 }
+
+func TestResolveExtensionsOrderIssue4053(t *testing.T) {
+	css_suite.expectBundled(t, bundled{
+		files: map[string]string{
+			"/entry.js": `
+				import test from "./Test"
+				import image from "expo-image"
+				console.log(test === 'Test.web.tsx')
+				console.log(image === 'Image.web.tsx')
+			`,
+			"/Test.web.tsx": `export default 'Test.web.tsx'`,
+			"/Test.tsx":     `export default 'Test.tsx'`,
+			"/node_modules/expo-image/index.js": `
+				export { default } from "./Image"
+			`,
+			"/node_modules/expo-image/Image.web.tsx": `export default 'Image.web.tsx'`,
+			"/node_modules/expo-image/Image.tsx":     `export default 'Image.tsx'`,
+		},
+		entryPaths: []string{"/entry.js"},
+		options: config.Options{
+			Mode:          config.ModeBundle,
+			AbsOutputFile: "/out.js",
+			ExtensionOrder: []string{
+				".web.mjs",
+				".mjs",
+				".web.js",
+				".js",
+				".web.mts",
+				".mts",
+				".web.ts",
+				".ts",
+				".web.jsx",
+				".jsx",
+				".web.tsx",
+				".tsx",
+				".json",
+			},
+		},
+	})
+}

internal/bundler_tests/snapshots/snapshots_css.txt

@@ -3443,6 +3443,19 @@ c {
   background: url(data:image/png;base64,Yy0z);
 }
 
+================================================================================
+TestResolveExtensionsOrderIssue4053
+---------- /out.js ----------
+// Test.web.tsx
+var Test_web_default = "Test.web.tsx";
+
+// node_modules/expo-image/Image.web.tsx
+var Image_web_default = "Image.web.tsx";
+
+// entry.js
+console.log(Test_web_default === "Test.web.tsx");
+console.log(Image_web_default === "Image.web.tsx");
+
 ================================================================================
 TestTextImportURLInCSSText
 ---------- /out/entry.css ----------

internal/config/config.go

@@ -256,6 +256,30 @@ func (loader Loader) CanHaveSourceMap() bool {
 	return false
 }
 
+func LoaderFromFileExtension(extensionToLoader map[string]Loader, base string) Loader {
+	// Pick the loader with the longest matching extension. So if there's an
+	// extension for ".css" and for ".module.css", we want to match the one for
+	// ".module.css" before the one for ".css".
+	if i := strings.IndexByte(base, '.'); i != -1 {
+		for {
+			if loader, ok := extensionToLoader[base[i:]]; ok {
+				return loader
+			}
+			base = base[i+1:]
+			i = strings.IndexByte(base, '.')
+			if i == -1 {
+				break
+			}
+		}
+	} else {
+		// If there's no extension, explicitly check for an extensionless loader
+		if loader, ok := extensionToLoader[""]; ok {
+			return loader
+		}
+	}
+	return LoaderNone
+}
+
 type Format uint8
 
 const (

internal/resolver/resolver.go

@@ -243,7 +243,7 @@ func NewResolver(call config.APICall, fs fs.FS, log logger.Log, caches *cache.Ca
 	// Filter out non-CSS extensions for CSS "@import" imports
 	cssExtensionOrder := make([]string, 0, len(options.ExtensionOrder))
 	for _, ext := range options.ExtensionOrder {
-		if loader, ok := options.ExtensionToLoader[ext]; !ok || loader.IsCSS() {
+		if loader := config.LoaderFromFileExtension(options.ExtensionToLoader, ext); loader == config.LoaderNone || loader.IsCSS() {
 			cssExtensionOrder = append(cssExtensionOrder, ext)
 		}
 	}
@@ -257,23 +257,23 @@ func NewResolver(call config.APICall, fs fs.FS, log logger.Log, caches *cache.Ca
 	nodeModulesExtensionOrder := make([]string, 0, len(options.ExtensionOrder))
 	split := 0
 	for i, ext := range options.ExtensionOrder {
-		if loader, ok := options.ExtensionToLoader[ext]; ok && loader == config.LoaderJS || loader == config.LoaderJSX {
+		if loader := config.LoaderFromFileExtension(options.ExtensionToLoader, ext); loader == config.LoaderJS || loader == config.LoaderJSX {
 			split = i + 1 // Split after the last JavaScript extension
 		}
 	}
 	if split != 0 { // Only do this if there are any JavaScript extensions
 		for _, ext := range options.ExtensionOrder[:split] { // Non-TypeScript extensions before the split
-			if loader, ok := options.ExtensionToLoader[ext]; !ok || !loader.IsTypeScript() {
+			if loader := config.LoaderFromFileExtension(options.ExtensionToLoader, ext); !loader.IsTypeScript() {
 				nodeModulesExtensionOrder = append(nodeModulesExtensionOrder, ext)
 			}
 		}
 		for _, ext := range options.ExtensionOrder { // All TypeScript extensions
-			if loader, ok := options.ExtensionToLoader[ext]; ok && loader.IsTypeScript() {
+			if loader := config.LoaderFromFileExtension(options.ExtensionToLoader, ext); loader.IsTypeScript() {
 				nodeModulesExtensionOrder = append(nodeModulesExtensionOrder, ext)
 			}
 		}
 		for _, ext := range options.ExtensionOrder[split:] { // Non-TypeScript extensions after the split
-			if loader, ok := options.ExtensionToLoader[ext]; !ok || !loader.IsTypeScript() {
+			if loader := config.LoaderFromFileExtension(options.ExtensionToLoader, ext); !loader.IsTypeScript() {
 				nodeModulesExtensionOrder = append(nodeModulesExtensionOrder, ext)
 			}
 		}