1 files changed, 74 insertions, 0 deletions
diff --git a/cli/tools/test/fmt.rs b/cli/tools/test/fmt.rs
new file mode 100644
index 000000000..d7b357a4b
--- /dev/null
+++ b/cli/tools/test/fmt.rs
@@ -0,0 +1,74 @@
+// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
+
+use super::*;
+
+pub fn to_relative_path_or_remote_url(cwd: &Url, path_or_url: &str) -> String {
+  let url = Url::parse(path_or_url).unwrap();
+  if url.scheme() == "file" {
+    if let Some(mut r) = cwd.make_relative(&url) {
+      if !r.starts_with("../") {
+        r = format!("./{r}");
+      }
+      return r;
+    }
+  }
+  path_or_url.to_string()
+}
+
+fn abbreviate_test_error(js_error: &JsError) -> JsError {
+  let mut js_error = js_error.clone();
+  let frames = std::mem::take(&mut js_error.frames);
+
+  // check if there are any stack frames coming from user code
+  let should_filter = frames.iter().any(|f| {
+    if let Some(file_name) = &f.file_name {
+      !(file_name.starts_with("[ext:") || file_name.starts_with("ext:"))
+    } else {
+      true
+    }
+  });
+
+  if should_filter {
+    let mut frames = frames
+      .into_iter()
+      .rev()
+      .skip_while(|f| {
+        if let Some(file_name) = &f.file_name {
+          file_name.starts_with("[ext:") || file_name.starts_with("ext:")
+        } else {
+          false
+        }
+      })
+      .collect::<Vec<_>>();
+    frames.reverse();
+    js_error.frames = frames;
+  } else {
+    js_error.frames = frames;
+  }
+
+  js_error.cause = js_error
+    .cause
+    .as_ref()
+    .map(|e| Box::new(abbreviate_test_error(e)));
+  js_error.aggregated = js_error
+    .aggregated
+    .as_ref()
+    .map(|es| es.iter().map(abbreviate_test_error).collect());
+  js_error
+}
+
+// This function prettifies `JsError` and applies some changes specifically for
+// test runner purposes:
+//
+// - filter out stack frames:
+//   - if stack trace consists of mixed user and internal code, the frames
+//     below the first user code frame are filtered out
+//   - if stack trace consists only of internal code it is preserved as is
+pub fn format_test_error(js_error: &JsError) -> String {
+  let mut js_error = abbreviate_test_error(js_error);
+  js_error.exception_message = js_error
+    .exception_message
+    .trim_start_matches("Uncaught ")
+    .to_string();
+  format_js_error(&js_error)
+}