support 'west config --list-paths'

The command prints a list of all configuration files currently
considered and existing. They are listed in the order as they are
loaded.

Author: thorsten-klein

src/west/app/config.py

@@ -35,17 +35,28 @@
 
 - Linux, macOS, Windows: <workspace-root-directory>/.west/config
 
-You can override these files' locations with the WEST_CONFIG_SYSTEM,
-WEST_CONFIG_GLOBAL, and WEST_CONFIG_LOCAL environment variables.
-
 Configuration values from later configuration files override configuration
 from earlier ones. Local values have highest precedence, and system values
 lowest.
 
-To get a value for <name>, type:
+The config file location for each according config level can be changed with
+environment variables:
+- WEST_CONFIG_SYSTEM
+- WEST_CONFIG_GLOBAL
+- WEST_CONFIG_LOCAL
+
+All `west config` commands can be applied for a specific configuration level by
+providing one of the following arguments:
+    --local | --system | --global
+
+The following command prints a list of all configuration files currently
+considered and existing (listed in the order as they are loaded):
+    west config --list-paths
+
+To get the value for config option <name>, type:
     west config <name>
 
-To set a value for <name>, type:
+To set a value for config option <name>, type:
     west config <name> <value>
 
 To append to a value for <name>, type:
@@ -99,6 +110,11 @@ def do_add_parser(self, parser_adder):
             "action to perform (give at most one)"
         ).add_mutually_exclusive_group()
 
+        group.add_argument(
+            '--list-paths',
+            action='store_true',
+            help='list all config files that are currently considered by west config',
+        )
         group.add_argument(
             '-l', '--list', action='store_true', help='list all options and their values'
         )
@@ -153,13 +169,15 @@ def do_run(self, args, user_args):
         if args.list:
             if args.name:
                 self.parser.error('-l cannot be combined with name argument')
-        elif not args.name:
+        elif not args.name and not args.list_paths:
             self.parser.error('missing argument name (to list all options and values, use -l)')
         elif args.append:
             if args.value is None:
                 self.parser.error('-a requires both name and value')
 
-        if args.list:
+        if args.list_paths:
+            self.list_paths(args)
+        elif args.list:
             self.list(args)
         elif delete:
             self.delete(args)
@@ -170,6 +188,11 @@ def do_run(self, args, user_args):
         else:
             self.write(args)
 
+    def list_paths(self, args):
+        config_paths = self.config.get_paths(args.configfile or ALL)
+        for config_path in config_paths:
+            self.inf(config_path)
+
     def list(self, args):
         what = args.configfile or ALL
         for option, value in self.config.items(configfile=what):

src/west/configuration.py

@@ -183,6 +183,16 @@ def __init__(self, topdir: PathType | None = None):
         self._global = _InternalCF.from_path(self._global_path)
         self._local = _InternalCF.from_path(self._local_path)
 
+    def get_paths(self, location: ConfigFile = ConfigFile.ALL):
+        ret = []
+        if self._global and location in [ConfigFile.GLOBAL, ConfigFile.ALL]:
+            ret.append(self._global.path)
+        if self._system and location in [ConfigFile.SYSTEM, ConfigFile.ALL]:
+            ret.append(self._system.path)
+        if self._local and location in [ConfigFile.LOCAL, ConfigFile.ALL]:
+            ret.append(self._local.path)
+        return ret
+
     def get(
         self, option: str, default: str | None = None, configfile: ConfigFile = ConfigFile.ALL
     ) -> str | None:

tests/test_config.py

@@ -6,6 +6,7 @@
 import os
 import pathlib
 import subprocess
+import textwrap
 from typing import Any
 
 import pytest
@@ -93,6 +94,77 @@ def test_config_global():
     assert 'pytest' not in lcl
 
 
+TEST_CASES_CONFIG_LIST_PATHS = [
+    # (flag, env_var)
+    ('--local', 'WEST_CONFIG_LOCAL'),
+    ('--system', 'WEST_CONFIG_SYSTEM'),
+    ('--global', 'WEST_CONFIG_GLOBAL'),
+]
+
+
+@pytest.mark.parametrize("test_case", TEST_CASES_CONFIG_LIST_PATHS)
+def test_config_list_paths_env(test_case):
+    '''Test that --list-paths considers the env variables'''
+    flag, env_var = test_case
+
+    # create the config
+    cmd(f'config {flag} pytest.key val')
+
+    # check that the config is listed now
+    stdout = cmd(f'config {flag} --list-paths')
+    config_path = pathlib.Path(os.environ[env_var])
+    assert f'{config_path}' == stdout.rstrip()
+
+    # config is only listed if it exists
+    config_path.unlink()
+    stdout = cmd(f'config {flag} --list-paths')
+    assert '' == stdout.rstrip()
+
+
+def test_config_list_paths():
+    WEST_CONFIG_LOCAL = os.environ['WEST_CONFIG_LOCAL']
+    WEST_CONFIG_GLOBAL = os.environ['WEST_CONFIG_GLOBAL']
+    WEST_CONFIG_SYSTEM = os.environ['WEST_CONFIG_SYSTEM']
+
+    # create the configs
+    cmd('config --local pytest.key val')
+    cmd('config --global pytest.key val')
+    cmd('config --system pytest.key val')
+
+    # list the configs
+    stdout = cmd('config --list-paths')
+    assert (
+        stdout.splitlines()
+        == textwrap.dedent(f'''\
+        {WEST_CONFIG_GLOBAL}
+        {WEST_CONFIG_SYSTEM}
+        {WEST_CONFIG_LOCAL}
+        ''').splitlines()
+    )
+
+    # do not list any configs if no config files currently exist
+    # (Note: even no local config exists, same as outside any west workspace)
+    pathlib.Path(WEST_CONFIG_GLOBAL).unlink()
+    pathlib.Path(WEST_CONFIG_SYSTEM).unlink()
+    pathlib.Path(WEST_CONFIG_LOCAL).unlink()
+    stdout = cmd('config --list-paths')
+    assert stdout.splitlines() == []
+
+    # list local config as it exists (determined from filesystem, not from env)
+    del os.environ['WEST_CONFIG_LOCAL']
+    default_config = pathlib.Path('.west') / 'config'
+    default_config.parent.mkdir()
+    default_config.write_text(
+        textwrap.dedent('''\
+        [manifest]
+        path = any
+        file = west.yml
+    ''')
+    )
+    stdout = cmd('config --list-paths')
+    assert stdout.splitlines() == [str(default_config.absolute())]
+
+
 def test_config_local():
     # test_config_system for local variables.
     cmd('config --local pytest.local foo')