Fix sub-modules end with .map (#1311)

Author: ije

server/build.go

@@ -143,8 +143,8 @@ func (ctx *BuildContext) Build() (meta *BuildMeta, err error) {
 		return
 	}
 
-	// analyze splitting modules
-	if ctx.bundleMode == BundleDefault && ctx.pkgJson.Exports.Len() > 1 {
+	// analyze splitting modules if bundling
+	if ctx.pkgJson.Exports.Len() > 1 && !ctx.isNoBundle() {
 		ctx.status = "analyze"
 		err = ctx.analyzeSplitting()
 		if err != nil {
@@ -369,14 +369,7 @@ func (ctx *BuildContext) buildModule(analyzeMode bool) (meta *BuildMeta, include
 
 	browserExclude := map[string]*set.Set[string]{}
 	implicitExternal := set.New[string]()
-	noBundle := ctx.bundleMode == BundleFalse || ctx.pkgJson.SideEffects.Len() > 0
-	if ctx.pkgJson.Esmsh != nil {
-		if v, ok := ctx.pkgJson.Esmsh["bundle"]; ok {
-			if b, ok := v.(bool); ok && !b {
-				noBundle = true
-			}
-		}
-	}
+	noBundle := ctx.isNoBundle()
 	esmifyPlugin := esbuild.Plugin{
 		Name: "esmify",
 		Setup: func(build esbuild.PluginBuild) {
@@ -1553,3 +1546,15 @@ func (ctx *BuildContext) install() (err error) {
 	}
 	return
 }
+
+func (ctx *BuildContext) isNoBundle() bool {
+	noBundle := ctx.bundleMode == BundleFalse || ctx.pkgJson.SideEffects.Len() > 0
+	if ctx.pkgJson.Esmsh != nil {
+		if v, ok := ctx.pkgJson.Esmsh["bundle"]; ok {
+			if b, ok := v.(bool); ok && !b {
+				noBundle = true
+			}
+		}
+	}
+	return noBundle
+}

server/router.go

@@ -1007,10 +1007,34 @@ func esmRouter(esmStorage storage.Storage, logger *log.Logger) rex.Handle {
 		rawFlag := query.Has("raw") || strings.HasPrefix(ctx.R.Host, "raw.")
 		if rawFlag {
 			pathKind = RawFile
-			if esmPath.SubPath != "" {
-				extname := path.Ext(pathname)
-				if !strings.HasSuffix(esmPath.SubPath, extname) {
-					esmPath.SubPath += extname
+		}
+
+		// restore the original path extension
+		if pathKind == RawFile && esmPath.SubPath != "" {
+			extname := path.Ext(pathname)
+			if !strings.HasSuffix(esmPath.SubPath, extname) {
+				esmPath.SubPath += extname
+			}
+		}
+
+		if pathKind == RawFile && !rawFlag && esmPath.SubPath != "" && strings.HasSuffix(esmPath.SubPath, ".map") {
+			pkgJson, err := npmrc.installPackage(esmPath.Package())
+			if err != nil {
+				return rex.Status(500, err.Error())
+			}
+			filename := path.Join(npmrc.StoreDir(), esmPath.ID(), "node_modules", esmPath.PkgName, esmPath.SubPath)
+			stat, err := os.Lstat(filename)
+			if err != nil {
+				if os.IsNotExist(err) {
+					if _, ok := pkgJson.Exports.Get("./" + esmPath.SubPath); ok {
+						pathKind = EsmEntry
+					}
+				} else {
+					return rex.Status(500, err.Error())
+				}
+			} else if stat.IsDir() {
+				if _, ok := pkgJson.Exports.Get("./" + esmPath.SubPath); ok {
+					pathKind = EsmEntry
 				}
 			}
 		}
@@ -1176,8 +1200,10 @@ func esmRouter(esmStorage storage.Storage, logger *log.Logger) rex.Handle {
 					if rawQuery != "" {
 						query = "?" + rawQuery
 					}
+					// redirect to the 'main' JS file
 					return redirect(ctx, fmt.Sprintf("%s/%s%s%s", origin, esmPath.ID(), utils.NormalizePathname(entry.main), query), true)
 				}
+
 				filename := path.Join(npmrc.StoreDir(), esmPath.ID(), "node_modules", esmPath.PkgName, esmPath.SubPath)
 				stat, err := os.Lstat(filename)
 				if err != nil && os.IsNotExist(err) {
@@ -1201,11 +1227,11 @@ func esmRouter(esmStorage storage.Storage, logger *log.Logger) rex.Handle {
 						}
 						entry := b.resolveEntry(esmPath)
 						if entry.main != "" && entry.main != "./"+esmPath.SubPath {
-							// redirect to the resolved path
 							query := ""
 							if rawQuery != "" {
 								query = "?" + rawQuery
 							}
+							// redirect to the resolved path
 							return redirect(ctx, fmt.Sprintf("%s/%s%s%s", origin, esmPath.ID(), utils.NormalizePathname(entry.main), query), true)
 						}
 						ctx.SetHeader("Cache-Control", ccImmutable)
@@ -1834,7 +1860,7 @@ func esmRouter(esmStorage storage.Storage, logger *log.Logger) rex.Handle {
 			}
 			ctx.SetHeader("Last-Modified", fi.ModTime().UTC().Format(http.TimeFormat))
 			ctx.SetHeader("Cache-Control", ccImmutable)
-			if endsWith(savePath, ".css") {
+			if strings.HasSuffix(savePath, ".css") {
 				ctx.SetHeader("Content-Type", ctCSS)
 			} else if endsWith(savePath, ".map") {
 				ctx.SetHeader("Content-Type", ctJSON)

test/issue-1285/test.ts

@@ -0,0 +1,12 @@
+import { assertEquals, assertStringIncludes } from "jsr:@std/assert";
+
+Deno.test("issue #1285 - Export path ending with .map fails to resolve", async () => {
+  const res = await fetch(
+    "http://localhost:8080/es-iterator-helpers@1.2.2/Iterator.prototype.map",
+    { headers: { "User-Agent": "i'm a browser" } },
+  );
+  const js = await res.text();
+  assertEquals(res.status, 200);
+  assertEquals(res.headers.get("content-type"), "application/javascript; charset=utf-8");
+  assertStringIncludes(js, 'export * from "/es-iterator-helpers@1.2.2/es2022/Iterator.prototype.map.mjs"');
+});