Fix svelte transformer (esm-dev#1357)

Author: ije

server/build.go

@@ -989,7 +989,11 @@ func (ctx *BuildContext) buildModule(analyzeMode bool) (meta *BuildMeta, include
 					if err != nil {
 						return esbuild.OnLoadResult{}, err
 					}
-					return esbuild.OnLoadResult{Contents: &out.Code, Loader: esbuild.LoaderJS}, nil
+					return esbuild.OnLoadResult{
+						Contents:   &out.Code,
+						ResolveDir: path.Join(ctx.wd, "node_modules", ctx.esmPath.PkgName),
+						Loader:     esbuild.LoaderJS,
+					}, nil
 				},
 			)
 
@@ -1024,9 +1028,17 @@ func (ctx *BuildContext) buildModule(analyzeMode bool) (meta *BuildMeta, include
 						return esbuild.OnLoadResult{}, err
 					}
 					if out.Lang == "ts" {
-						return esbuild.OnLoadResult{Contents: &out.Code, Loader: esbuild.LoaderTS}, nil
+						return esbuild.OnLoadResult{
+							Contents:   &out.Code,
+							ResolveDir: path.Join(ctx.wd, "node_modules", ctx.esmPath.PkgName),
+							Loader:     esbuild.LoaderTS,
+						}, nil
 					}
-					return esbuild.OnLoadResult{Contents: &out.Code, Loader: esbuild.LoaderJS}, nil
+					return esbuild.OnLoadResult{
+						Contents:   &out.Code,
+						ResolveDir: path.Join(ctx.wd, "node_modules", ctx.esmPath.PkgName),
+						Loader:     esbuild.LoaderJS,
+					}, nil
 				},
 			)
 		},

test/issue-1233/test.ts

@@ -0,0 +1,14 @@
+import { assertEquals, assertStringIncludes } from "jsr:@std/assert";
+
+Deno.test("issue #1233 - Svelte loader", async () => {
+  {
+    const res = await fetch(
+      "http://localhost:8080/@onsvisual/svelte-components@1.1.20/dist/components/Section/Section.svelte",
+      { 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, '/js/utils?target=es2022');
+  }
+});