denoland/deno · error · anyhow::Error

Invalid file path: {}

Error message

Invalid file path: {}

What it means

Each input path is converted to a `file://` ModuleSpecifier before transpiling. `ModuleSpecifier::from_file_path` fails for paths that cannot become a valid file URL — an empty path or bytes that are not valid UTF-8 — and that failure surfaces as this error with the printed path.

Source

Thrown at cli/tools/transpile.rs:95

  // Collect file paths and specifiers
  let mut file_entries = Vec::new();
  for file_path_str in files {
    let file_path = cwd.join(file_path_str);

    let media_type = MediaType::from_path(&file_path);
    if !media_type.is_emittable() {
      log::warn!(
        "{} Skipping {} (not a TypeScript/JSX/TSX file)",
        colors::yellow("Warning"),
        file_path.display()
      );
      continue;
    }

    let specifier =
      ModuleSpecifier::from_file_path(&file_path).map_err(|_| {
        anyhow::anyhow!("Invalid file path: {}", file_path.display())
      })?;

    file_entries.push((file_path, specifier, media_type));
  }

  if file_entries.is_empty() {
    anyhow::bail!(
      "No emittable files found. Only TypeScript/JSX/TSX files can be transpiled."
    );
  }

  // Transpile each file (TS -> JS)
  for (file_path, specifier, media_type) in &file_entries {
    let source_bytes = sys
      .fs_read(file_path)
      .with_context(|| format!("Failed to read {}", file_path.display()))?;
    let source_code = String::from_utf8(source_bytes.into_owned())
      .with_context(|| format!("{} is not valid UTF-8", file_path.display()))?;

View on GitHub (pinned to 89f33cbef2)

Solutions

1. Reproduce and inspect the argument (`printf '%s' "$arg" | od -c`) and fix or rename it to valid UTF-8
2. Quote and null-check variables in the calling script so empty values fail before deno runs
3. Add `set -u` (or equivalent) to catch unset variables in wrapper scripts

Example fix

# before
deno transpile "$MAYBE_EMPTY"
# after
[ -n "$MAYBE_EMPTY" ] && deno transpile "$MAYBE_EMPTY"

# bash: reject empty and non-UTF-8 args up front
for f in "$@"; do
  [ -n "$f" ] || { echo "empty path argument" >&2; exit 1; }
  printf '%s' "$f" | LC_ALL=C grep -qP '[\x80-\xFF]' && { echo "non-UTF-8 path: $f" >&2; exit 1; }
done
deno transpile "$@"

When it happens

Trigger: A path argument that resolves to an empty string, or a filename containing non-UTF-8 bytes (e.g. from locale-mangled glob expansion or an unvalidated variable).

Common situations: Scripts that build paths from unvalidated environment variables; Unix filenames created with invalid encoding; empty-string expansion of `$FILE` reaching the CLI.

Related errors

• Declaration file {} is not under the current directory
• Invalid declaration file path
• Input file {} is not under the current directory. Use --outp
• No input files specified
• Cannot use --output with multiple input files. Use --outdir

AI-assisted analysis of denoland/deno@89f33cbef2 (2026-08-16). Data as JSON: /api/errors/138eca8d1ac3dd18. Report an issue: GitHub.