Change unknown cmd message when outside project (#3426)

* Change unknown cmd message when outside project

* Simplification.

* Move the import to the top level.

* Reword the message.

---------

Co-authored-by: Andrey Rakhmatullin <wrar@wrar.name>

scrapy/cmdline.py

@@ -89,6 +89,12 @@ def _get_commands_dict(
     return cmds
 
 
+def _get_project_only_cmds(settings: BaseSettings) -> set[str]:
+    return set(_get_commands_dict(settings, inproject=True)) - set(
+        _get_commands_dict(settings, inproject=False)
+    )
+
+
 def _pop_command_name(argv: list[str]) -> str | None:
     for i, arg in enumerate(argv[1:]):
         if not arg.startswith("-"):
@@ -121,11 +127,25 @@ def _print_commands(settings: BaseSettings, inproject: bool) -> None:
     print('Use "scrapy <command> -h" to see more info about a command')
 
 
+def _print_unknown_command_msg(
+    settings: BaseSettings, cmdname: str, inproject: bool
+) -> None:
+    proj_only_cmds = _get_project_only_cmds(settings)
+    if cmdname in proj_only_cmds and not inproject:
+        cmd_list = ", ".join(sorted(proj_only_cmds))
+        print(
+            f"The {cmdname} command is not available from this location.\n"
+            f"These commands are only available from within a project: {cmd_list}.\n"
+        )
+    else:
+        print(f"Unknown command: {cmdname}\n")
+
+
 def _print_unknown_command(
     settings: BaseSettings, cmdname: str, inproject: bool
 ) -> None:
     _print_header(settings, inproject)
-    print(f"Unknown command: {cmdname}\n")
+    _print_unknown_command_msg(settings, cmdname, inproject)
     print('Use "scrapy" to see available commands')
 
 

tests/test_commands.py

@@ -9,6 +9,7 @@ import re
 import subprocess
 import sys
 from contextlib import contextmanager
+from io import StringIO
 from itertools import chain
 from pathlib import Path
 from shutil import copytree, rmtree
@@ -16,12 +17,13 @@ from stat import S_IWRITE as ANYONE_WRITE_PERMISSION
 from tempfile import TemporaryFile, mkdtemp
 from threading import Timer
 from typing import TYPE_CHECKING
-from unittest import skipIf
+from unittest import mock, skipIf
 
 from pytest import mark
 from twisted.trial import unittest
 
 import scrapy
+from scrapy.cmdline import _print_unknown_command_msg
 from scrapy.commands import ScrapyCommand, ScrapyHelpFormatter, view
 from scrapy.commands.startproject import IGNORE
 from scrapy.settings import Settings
@@ -652,6 +654,24 @@ class MiscCommandsTest(CommandTest):
     def test_list(self):
         self.assertEqual(0, self.call("list"))
 
+    def test_command_not_found(self):
+        na_msg = """
+The list command is not available from this location.
+These commands are only available from within a project: check, crawl, edit, list, parse.
+"""
+        not_found_msg = """
+Unknown command: abc
+"""
+        params = [
+            ("list", 0, na_msg),
+            ("abc", 0, not_found_msg),
+            ("abc", 1, not_found_msg),
+        ]
+        for cmdname, inproject, message in params:
+            with mock.patch("sys.stdout", new=StringIO()) as out:
+                _print_unknown_command_msg(Settings(), cmdname, inproject)
+                self.assertEqual(out.getvalue().strip(), message.strip())
+
 
 class RunSpiderCommandTest(CommandTest):
     spider_filename = "myspider.py"