1 files changed, 62 insertions, 0 deletions
diff --git a/cli/fs_util.rs b/cli/fs_util.rs
index 54bb8f3c6..20b20cccd 100644
--- a/cli/fs_util.rs
+++ b/cli/fs_util.rs
@@ -350,6 +350,37 @@ pub fn specifier_to_file_path(
   }
 }
 
+/// Ensures a specifier that will definitely be a directory has a trailing slash.
+pub fn ensure_directory_specifier(
+  mut specifier: ModuleSpecifier,
+) -> ModuleSpecifier {
+  let path = specifier.path();
+  if !path.ends_with('/') {
+    let new_path = format!("{}/", path);
+    specifier.set_path(&new_path);
+  }
+  specifier
+}
+
+/// Gets the parent of this module specifier.
+pub fn specifier_parent(specifier: &ModuleSpecifier) -> ModuleSpecifier {
+  let mut specifier = specifier.clone();
+  // don't use specifier.segments() because it will strip the leading slash
+  let mut segments = specifier.path().split('/').collect::<Vec<_>>();
+  if segments.iter().all(|s| s.is_empty()) {
+    return specifier;
+  }
+  if let Some(last) = segments.last() {
+    if last.is_empty() {
+      segments.pop();
+    }
+    segments.pop();
+    let new_path = format!("{}/", segments.join("/"));
+    specifier.set_path(&new_path);
+  }
+  specifier
+}
+
 #[cfg(test)]
 mod tests {
   use super::*;
@@ -688,4 +719,35 @@ mod tests {
       assert_eq!(result, PathBuf::from(expected_path));
     }
   }
+
+  #[test]
+  fn test_ensure_directory_specifier() {
+    run_test("file:///", "file:///");
+    run_test("file:///test", "file:///test/");
+    run_test("file:///test/", "file:///test/");
+    run_test("file:///test/other", "file:///test/other/");
+    run_test("file:///test/other/", "file:///test/other/");
+
+    fn run_test(specifier: &str, expected: &str) {
+      let result =
+        ensure_directory_specifier(ModuleSpecifier::parse(specifier).unwrap());
+      assert_eq!(result.to_string(), expected);
+    }
+  }
+
+  #[test]
+  fn test_specifier_parent() {
+    run_test("file:///", "file:///");
+    run_test("file:///test", "file:///");
+    run_test("file:///test/", "file:///");
+    run_test("file:///test/other", "file:///test/");
+    run_test("file:///test/other.txt", "file:///test/");
+    run_test("file:///test/other/", "file:///test/");
+
+    fn run_test(specifier: &str, expected: &str) {
+      let result =
+        specifier_parent(&ModuleSpecifier::parse(specifier).unwrap());
+      assert_eq!(result.to_string(), expected);
+    }
+  }
 }