test(lint): cover file URL config imports

Author: samchon

packages/lint/linthost/config.go

@@ -1242,30 +1242,48 @@ func isConfigObject(value any) bool {
   return ok
 }
 
-// relativeImportSpecifier computes the ESM import specifier for `location`
-// relative to `fromDir`. The result always starts with "./" or "../" so it is
-// treated as a relative path by the ESM loader rather than as a bare package
-// name.
-func relativeImportSpecifier(fromDir, location string) (string, error) {
-  relative, err := filepath.Rel(fromDir, location)
-  if err != nil {
-    return "", fmt.Errorf("@ttsc/lint: resolve relative config import %s: %w", location, err)
-  }
-  relative = filepath.ToSlash(relative)
-  if strings.HasPrefix(relative, "../") || strings.HasPrefix(relative, "./") {
-    return relative, nil
-  }
-  return "./" + relative, nil
-}
-
 func fileURL(location string) string {
+  volume := filepath.VolumeName(location)
+  if volume != "" {
+    volumePath := filepath.ToSlash(volume)
+    rest := strings.TrimPrefix(filepath.ToSlash(location[len(volume):]), "/")
+    if strings.HasPrefix(volumePath, "//?/UNC") {
+      return uncFileURL(rest)
+    }
+    if strings.HasPrefix(volumePath, "//?/") {
+      pathname := "/" + strings.TrimPrefix(volumePath, "//?/")
+      if rest != "" {
+        pathname += "/" + rest
+      }
+      return (&url.URL{Scheme: "file", Path: pathname}).String()
+    }
+    if strings.HasPrefix(volumePath, "//") {
+      return uncFileURL(strings.TrimPrefix(volumePath, "//") + "/" + rest)
+    }
+  }
   pathname := filepath.ToSlash(location)
-  if filepath.VolumeName(location) != "" && !strings.HasPrefix(pathname, "/") {
+  if volume != "" && !strings.HasPrefix(pathname, "/") {
     pathname = "/" + pathname
   }
   return (&url.URL{Scheme: "file", Path: pathname}).String()
 }
 
+func uncFileURL(pathname string) string {
+  server, remainder, ok := strings.Cut(pathname, "/")
+  if !ok || server == "" {
+    return (&url.URL{Scheme: "file", Path: "/" + strings.TrimPrefix(pathname, "/")}).String()
+  }
+  share, tail, _ := strings.Cut(remainder, "/")
+  if share == "" {
+    return (&url.URL{Scheme: "file", Path: "/" + strings.TrimPrefix(pathname, "/")}).String()
+  }
+  urlPath := "/" + share
+  if tail != "" {
+    urlPath += "/" + tail
+  }
+  return (&url.URL{Scheme: "file", Host: server, Path: urlPath}).String()
+}
+
 // typeScriptConfigLoaderSource returns the TypeScript source of the ephemeral
 // loader script that ttsx executes to evaluate a TypeScript lint config file.
 // `importLiteral` is a JSON-encoded file URL (produced by json.Marshal). It is

packages/lint/test/config/file_url_matches_node_shape_test.go

@@ -0,0 +1,59 @@
+package linthost
+
+import (
+  "runtime"
+  "testing"
+)
+
+// TestFileURLMatchesNodeShape pins the file URL strings generated for the
+// ephemeral TypeScript config loader. Node consumes these with dynamic import,
+// so the Go side must match Node's pathToFileURL shape for Windows drive and
+// UNC paths, including characters that require URL escaping.
+func TestFileURLMatchesNodeShape(t *testing.T) {
+  type testCase struct {
+    name     string
+    location string
+    want     string
+  }
+
+  cases := []testCase{
+    {
+      name:     "posix escapes path characters",
+      location: "/tmp/a b/#lint%.config.ts",
+      want:     "file:///tmp/a%20b/%23lint%25.config.ts",
+    },
+  }
+
+  if runtime.GOOS == "windows" {
+    cases = append(cases,
+      testCase{
+        name:     "windows drive path",
+        location: `C:\a b\#lint%.config.ts`,
+        want:     "file:///C:/a%20b/%23lint%25.config.ts",
+      },
+      testCase{
+        name:     "windows unc path",
+        location: `\\server\share\a b\lint.config.ts`,
+        want:     "file://server/share/a%20b/lint.config.ts",
+      },
+      testCase{
+        name:     "windows extended drive path",
+        location: `\\?\C:\a b\lint.config.ts`,
+        want:     "file:///C:/a%20b/lint.config.ts",
+      },
+      testCase{
+        name:     "windows extended unc path",
+        location: `\\?\UNC\server\share\a b\lint.config.ts`,
+        want:     "file://server/share/a%20b/lint.config.ts",
+      },
+    )
+  }
+
+  for _, c := range cases {
+    t.Run(c.name, func(t *testing.T) {
+      if got := fileURL(c.location); got != c.want {
+        t.Fatalf("fileURL(%q) = %q, want %q", c.location, got, c.want)
+      }
+    })
+  }
+}