Added error handling

cli/cli.py

@@ -2,11 +2,33 @@
 CLI entry point for the 101 Linux Commands application.
 """
 
+from typing import List
+
+import click
 import typer
+from typer.main import TyperGroup
 
 from commands import hello, list, search, show, version
 
-app = typer.Typer(help="101 Linux Commands CLI 🚀")
+
+class CustomTyper(TyperGroup):
+    def resolve_command(self, ctx: click.Context, args: List[str]):
+        try:
+            return super().resolve_command(ctx, args)
+        except click.exceptions.UsageError as e:
+            original = e.format_message()
+
+            if "No such command" in original:
+                script_name = ctx.find_root().info_name or "cli"
+                hint = f"💡 Hint: Run '{script_name} --help' to see available commands."
+
+                new_message = f"{original}\n{hint}"
+                raise click.exceptions.UsageError(new_message, ctx=ctx) from e
+
+            raise
+
+
+app = typer.Typer(help="101 Linux Commands CLI 🚀", cls=CustomTyper)
 app.add_typer(hello.app, name="hello")
 app.add_typer(list.app, name="list")
 app.add_typer(version.app, name="version")

cli/test_cli.py

@@ -2,6 +2,7 @@
 """Basic tests for the CLI module."""
 
 import os
+import re
 import subprocess
 import sys
 
@@ -70,6 +71,26 @@ def test_version_show_command():
     assert "101-linux v0.1.0" in result.stdout
 
 
+ANSI_ESCAPE = re.compile(r"\x1B\[[0-?]*[ -/]*[@-~]")
+EMOJI = re.compile("[\U0001f300-\U0001faff]", flags=re.UNICODE)
+
+
+def clean_output(text: str) -> str:
+    """Remove ANSI colors and emojis."""
+    text = ANSI_ESCAPE.sub("", text)
+    text = EMOJI.sub("", text)
+    return text
+
+
+def test_unknown_command():
+    result = run_cli(["unknowncmd"])
+    combined_output = result.stdout + result.stderr
+    clean = clean_output(combined_output)
+
+    assert "No such command" in clean
+    assert "Hint: Run 'cli.py --help' to see available commands." in clean
+
+
 # ----------------------------
 # Tests for `show` subcommand
 # ----------------------------
@@ -138,4 +159,5 @@ def test_search_no_match():
     test_show_invalid()
     test_search_match()
     test_search_no_match()
+    test_unknown_command()
     print("✅ All tests passed!")