4 files changed, 128 insertions, 11 deletions

diff --git a/cli/lsp/diagnostics.rs b/cli/lsp/diagnostics.rs
index e3b922ba8..03d962741 100644
--- a/cli/lsp/diagnostics.rs
+++ b/cli/lsp/diagnostics.rs
@@ -21,6 +21,7 @@ use crate::graph_util::enhanced_resolution_error_message;
 use crate::lsp::lsp_custom::DiagnosticBatchNotificationParams;
 use crate::resolver::SloppyImportsResolution;
 use crate::resolver::SloppyImportsResolver;
+use crate::util::path::to_percent_decoded_str;
 
 use deno_ast::MediaType;
 use deno_core::anyhow::anyhow;
@@ -1212,8 +1213,10 @@ impl DenoDiagnostic {
       specifier: &ModuleSpecifier,
       sloppy_resolution: SloppyImportsResolution,
     ) -> String {
-      let mut message =
-        format!("Unable to load a local module: {}\n", specifier);
+      let mut message = format!(
+        "Unable to load a local module: {}\n",
+        to_percent_decoded_str(specifier.as_ref())
+      );
       if let Some(additional_message) =
         sloppy_resolution.as_suggestion_message()
       {
@@ -1971,6 +1974,50 @@ let c: number = "a";
     );
   }
 
+  #[tokio::test]
+  async fn unable_to_load_a_local_module() {
+    let temp_dir = TempDir::new();
+    let (snapshot, _) = setup(
+      &temp_dir,
+      &[(
+        "file:///a.ts",
+        r#"
+        import { 東京 } from "./🦕.ts";
+        "#,
+        1,
+        LanguageId::TypeScript,
+      )],
+      None,
+    )
+    .await;
+    let config = mock_config();
+    let token = CancellationToken::new();
+    let actual = generate_deno_diagnostics(&snapshot, &config, token);
+    assert_eq!(actual.len(), 1);
+    let record = actual.first().unwrap();
+    assert_eq!(
+      json!(record.versioned.diagnostics),
+      json!([
+        {
+          "range": {
+            "start": {
+              "line": 1,
+              "character": 27
+            },
+            "end": {
+              "line": 1,
+              "character": 35
+            }
+          },
+          "severity": 1,
+          "code": "no-local",
+          "source": "deno",
+          "message": "Unable to load a local module: file:///🦕.ts\nPlease check the file path.",
+        }
+      ])
+    );
+  }
+
   #[test]
   fn test_specifier_text_for_redirected() {
     #[track_caller]
diff --git a/cli/lsp/language_server.rs b/cli/lsp/language_server.rs
index fafd9fe4c..e7e48a04c 100644
--- a/cli/lsp/language_server.rs
+++ b/cli/lsp/language_server.rs
@@ -122,6 +122,7 @@ use crate::tools::upgrade::upgrade_check_enabled;
 use crate::util::fs::remove_dir_all_if_exists;
 use crate::util::path::is_importable_ext;
 use crate::util::path::specifier_to_file_path;
+use crate::util::path::to_percent_decoded_str;
 use crate::util::progress_bar::ProgressBar;
 use crate::util::progress_bar::ProgressBarStyle;
 
@@ -1738,16 +1739,21 @@ impl Inner {
     match resolution {
       Resolution::Ok(resolved) => {
         let specifier = &resolved.specifier;
+        let format = |scheme: &str, rest: &str| -> String {
+          format!("{}​{}", scheme, rest).replace('@', "​@")
+        };
         match specifier.scheme() {
           "data" => "_(a data url)_".to_string(),
           "blob" => "_(a blob url)_".to_string(),
+          "file" => format(
+            &specifier[..url::Position::AfterScheme],
+            &to_percent_decoded_str(&specifier[url::Position::AfterScheme..]),
+          ),
           _ => {
-            let mut result = format!(
-              "{}​{}",
+            let mut result = format(
               &specifier[..url::Position::AfterScheme],
               &specifier[url::Position::AfterScheme..],
-            )
-            .replace('@', "​@");
+            );
             if let Ok(jsr_req_ref) =
               JsrPackageReqReference::from_specifier(specifier)
             {
diff --git a/cli/lsp/tsc.rs b/cli/lsp/tsc.rs
index 4eb425c1f..691f7c91d 100644
--- a/cli/lsp/tsc.rs
+++ b/cli/lsp/tsc.rs
@@ -31,6 +31,7 @@ use crate::tsc;
 use crate::tsc::ResolveArgs;
 use crate::util::path::relative_specifier;
 use crate::util::path::specifier_to_file_path;
+use crate::util::path::to_percent_decoded_str;
 
 use dashmap::DashMap;
 use deno_ast::MediaType;
@@ -543,6 +544,10 @@ impl TsServer {
       .and_then(|mut changes| {
         for changes in &mut changes {
           changes.normalize(&self.specifier_map)?;
+          for text_changes in &mut changes.text_changes {
+            text_changes.new_text =
+              to_percent_decoded_str(&text_changes.new_text);
+          }
         }
         Ok(changes)
       })
@@ -1611,7 +1616,41 @@ fn display_parts_to_string(
           link.name = Some(part.text.clone());
         }
       }
-      _ => out.push(part.text.clone()),
+      _ => out.push(
+        // should decode percent-encoding string when hovering over the right edge of module specifier like below
+        // module "file:///path/to/🦕"
+        to_percent_decoded_str(&part.text),
+        // NOTE: The reason why an example above that lacks `.ts` extension is caused by the implementation of tsc itself.
+        // The request `tsc.request.getQuickInfoAtPosition` receives the payload from tsc host as follows.
+        // {
+        //   text_span: {
+        //     start: 19,
+        //     length: 9,
+        //   },
+        //   displayParts:
+        //     [
+        //       {
+        //         text: "module",
+        //         kind: "keyword",
+        //         target: null,
+        //       },
+        //       {
+        //         text: " ",
+        //         kind: "space",
+        //         target: null,
+        //       },
+        //       {
+        //         text: "\"file:///path/to/%F0%9F%A6%95\"",
+        //         kind: "stringLiteral",
+        //         target: null,
+        //       },
+        //     ],
+        //   documentation: [],
+        //   tags: null,
+        // }
+        //
+        // related issue: https://github.com/denoland/deno/issues/16058
+      ),
     }
   }
 
@@ -5424,7 +5463,7 @@ mod tests {
       .get_edits_for_file_rename(
         snapshot,
         resolve_url("file:///b.ts").unwrap(),
-        resolve_url("file:///c.ts").unwrap(),
+        resolve_url("file:///🦕.ts").unwrap(),
         FormatCodeSettings::default(),
         UserPreferences::default(),
       )
@@ -5439,7 +5478,7 @@ mod tests {
             start: 8,
             length: 6,
           },
-          new_text: "./c.ts".to_string(),
+          new_text: "./🦕.ts".to_string(),
         }],
         is_new_file: None,
       }]
diff --git a/cli/util/path.rs b/cli/util/path.rs
index b64fde6b9..144676c01 100644
--- a/cli/util/path.rs
+++ b/cli/util/path.rs
@@ -156,11 +156,12 @@ pub fn relative_specifier(
     text.push('/');
   }
 
-  Some(if text.starts_with("../") || text.starts_with("./") {
+  let text = if text.starts_with("../") || text.starts_with("./") {
     text
   } else {
     format!("./{text}")
-  })
+  };
+  Some(to_percent_decoded_str(&text))
 }
 
 /// Gets a path with the specified file stem suffix.
@@ -265,6 +266,24 @@ pub fn matches_pattern_or_exact_path(
   false
 }
 
+/// For decoding percent-encodeing string
+/// could be used for module specifier string literal of local modules,
+/// or local file path to display `non-ASCII` characters correctly
+/// # Examples
+/// ```
+/// use crate::util::path::to_percent_decoded_str;
+///
+/// let str = to_percent_decoded_str("file:///Users/path/to/%F0%9F%A6%95.ts");
+/// assert_eq!(str, "file:///Users/path/to/🦕.ts");
+/// ```
+pub fn to_percent_decoded_str(s: &str) -> String {
+  match percent_encoding::percent_decode_str(s).decode_utf8() {
+    Ok(s) => s.to_string(),
+    // when failed to decode, return the original string
+    Err(_) => s.to_string(),
+  }
+}
+
 #[cfg(test)]
 mod test {
   use super::*;
@@ -457,4 +476,10 @@ mod test {
       PathBuf::from("/test_2.d.cts")
     );
   }
+
+  #[test]
+  fn test_to_percent_decoded_str() {
+    let str = to_percent_decoded_str("%F0%9F%A6%95");
+    assert_eq!(str, "🦕");
+  }
 }