Make 'spack location -e' print the current env, and 'spack cd -e' go to the current env (#26654)

lib/spack/spack/cmd/location.py

@@ -56,8 +56,8 @@ def setup_parser(subparser):
         help="build directory for a spec "
              "(requires it to be staged first)")
     directories.add_argument(
-        '-e', '--env', action='store', dest='location_env',
-        help="location of an environment managed by spack")
+        '-e', '--env', action='store', dest='location_env', nargs='?', metavar="name",
+        default=False, help="location of the named or current environment")
 
     arguments.add_common_arguments(subparser, ['spec'])
 
@@ -71,10 +71,17 @@ def location(parser, args):
         print(spack.paths.prefix)
         return
 
-    if args.location_env:
-        path = ev.root(args.location_env)
-        if not os.path.isdir(path):
-            tty.die("no such environment: '%s'" % args.location_env)
+    # no -e corresponds to False, -e without arg to None, -e name to the string name.
+    if args.location_env is not False:
+        if args.location_env is None:
+            # Get current environment path
+            spack.cmd.require_active_env('location -e')
+            path = ev.active_environment().path
+        else:
+            # Get named environment path
+            if not ev.exists(args.location_env):
+                tty.die("no such environment: '%s'" % args.location_env)
+            path = ev.root(args.location_env)
         print(path)
         return
 

lib/spack/spack/test/cmd/location.py

@@ -23,17 +23,6 @@
 env = SpackCommand('env')
 
 
-@pytest.fixture
-def mock_test_env():
-    test_env_name = 'test'
-    env_dir = ev.root(test_env_name)
-    mkdirp(env_dir)
-    yield test_env_name, env_dir
-
-    # Remove the temporary test environment directory created above
-    shutil.rmtree(env_dir)
-
-
 @pytest.fixture
 def mock_spec():
     spec = spack.spec.Spec('externaltest').concretized()
@@ -82,10 +71,19 @@ def test_location_cmd_error(options):
         location(*options)
 
 
-def test_location_env(mock_test_env):
-    """Tests spack location --env."""
-    test_env_name, env_dir = mock_test_env
-    assert location('--env', test_env_name).strip() == env_dir
+def test_location_env_exists(mutable_mock_env_path):
+    """Tests spack location --env <name> for an existing environment."""
+    e = ev.create("example")
+    e.write()
+    assert location('--env', "example").strip() == e.path
+
+
+def test_location_with_active_env(mutable_mock_env_path):
+    """Tests spack location --env with active env"""
+    e = ev.create("example")
+    e.write()
+    with e:
+        assert location('--env').strip() == e.path
 
 
 def test_location_env_flag_interference(mutable_mock_env_path, tmpdir):