Parallelize spell check

Author: yaugenst-flex

spellcheck.py

@@ -1,6 +1,9 @@
 #!/usr/bin/env python3
 
 import argparse
+
+import concurrent.futures
+
 import os
 import re
 import subprocess
@@ -98,21 +101,35 @@ def main():
     num_files_with_errors = 0
     num_files_with_processing_errors = 0
 
-    for notebook in args.notebooks:
-        num_files_processed += 1
-        error_output = check_spelling(notebook)
-        if error_output:
-            all_errors.append(error_output)
-            if (
-                "Error running command" in error_output
-                or "An unexpected error occurred" in error_output
-                or "Error - File not found" in error_output
-            ):
+    futures = []
+    with concurrent.futures.ProcessPoolExecutor() as executor:
+        for notebook in args.notebooks:
+            futures.append(executor.submit(check_spelling, notebook))
+
+        for future in concurrent.futures.as_completed(futures):
+            num_files_processed += 1
+            try:
+                error_output = future.result()
+                if error_output:
+                    all_errors.append(error_output)
+                    if (
+                        "Error running command" in error_output
+                        or "An unexpected error occurred" in error_output
+                        or "Error - File not found" in error_output
+                    ):
+                        num_files_with_processing_errors += 1
+                    else:
+                        num_files_with_errors += 1
+            except Exception as exc:
+                print(f"An unexpected error occurred processing a task: {exc}", file=sys.stderr)
                 num_files_with_processing_errors += 1
-            else:
-                num_files_with_errors += 1
+                all_errors.append(
+                    f"**Unknown File**: An unexpected error occurred during processing:\n```\n{exc}\n```"
+                )
 
     if all_errors:
+        all_errors.sort()
+
         print("## Spell Check Report\n")
         print("\n\n---\n\n".join(all_errors))
 
@@ -123,13 +140,15 @@ def main():
             summary_lines.append(
                 f"Encountered processing errors in {num_files_with_processing_errors} file(s)."
             )
-        if not summary_lines:
+        if not summary_lines and all_errors:
             summary_lines.append(f"Found issues in {len(all_errors)} file(s).")
 
-        print(f"\n---\nChecked {num_files_processed} notebook(s). " + " ".join(summary_lines))
+        total_notebooks_input = len(args.notebooks)
+        print(f"\n---\nChecked {total_notebooks_input} notebook(s). " + " ".join(summary_lines))
         sys.exit(1)
     else:
-        print(f"Spell check passed successfully for {num_files_processed} notebook(s).")
+        total_notebooks_input = len(args.notebooks)
+        print(f"Spell check passed successfully for {total_notebooks_input} notebook(s).")
         sys.exit(0)