fix(extensions): delete the catalog config when the last entry is removed

src/specify_cli/extensions/catalog/command_remove.py

@@ -48,16 +48,21 @@ def catalog_remove(
         _commands.console.print(f"[red]Error:[/red] Catalog '{safe_name}' not found.")
         raise typer.Exit(1)
 
-    config["catalogs"] = catalogs
-    config_path.write_text(
-        _commands.yaml.safe_dump(
-            config,
-            default_flow_style=False,
-            sort_keys=False,
-            allow_unicode=True,
-        ),
-        encoding="utf-8",
-    )
+    if catalogs:
+        config["catalogs"] = catalogs
+        config_path.write_text(
+            _commands.yaml.safe_dump(
+                config,
+                default_flow_style=False,
+                sort_keys=False,
+                allow_unicode=True,
+            ),
+            encoding="utf-8",
+        )
+    else:
+        # The catalog loader rejects an existing config with no entries, so
+        # delete the file instead of writing ``catalogs: []``.
+        config_path.unlink(missing_ok=True)
 
     _commands.console.print(f"[green]✓[/green] Removed catalog '{safe_name}'")
     if not catalogs:

tests/specify_cli/extensions/catalog/test_command_remove.py

@@ -73,3 +73,77 @@ def test_extension_catalog_remove_escapes_catalog_name_markup(self, tmp_path):
         assert result.exit_code == 0, result.output
         output = _normalize_cli_output(result.output)
         assert f"Removed catalog '{catalog_name}'" in output
+
+    def test_extension_catalog_remove_final_entry_restores_defaults(
+        self, tmp_path, monkeypatch
+    ):
+        """The loader rejects an empty ``catalogs`` list, so removing the last
+        entry must not leave one behind for follow-up commands to trip on."""
+        project = self._make_project(tmp_path)
+        monkeypatch.setenv("HOME", str(tmp_path))
+        monkeypatch.setenv("USERPROFILE", str(tmp_path))
+        monkeypatch.delenv("SPECKIT_CATALOG_URL", raising=False)
+
+        add = self._invoke(
+            [
+                "extension",
+                "catalog",
+                "add",
+                "https://only.example.com/catalog.json",
+                "--name",
+                "only",
+            ],
+            project,
+        )
+        assert add.exit_code == 0, add.output
+
+        remove = self._invoke(["extension", "catalog", "remove", "only"], project)
+        assert remove.exit_code == 0, remove.output
+        assert "Built-in defaults will be used" in _normalize_cli_output(remove.output)
+
+        listing = self._invoke(["extension", "catalog", "list"], project)
+        assert listing.exit_code == 0, listing.output
+        output = _normalize_cli_output(listing.output)
+        assert "default (priority 1)" in output
+        assert "community (priority 2)" in output
+        assert "Using built-in default catalog stack" in output
+        assert not (project / ".specify" / "extension-catalogs.yml").exists()
+
+    def test_extension_catalog_remove_keeps_config_with_remaining_entries(
+        self, tmp_path
+    ):
+        project = self._make_project(tmp_path)
+        keep = {
+            "name": "keep",
+            "url": "https://keep.example.com/catalog.json",
+            "priority": 20,
+            "install_allowed": False,
+            "description": "",
+        }
+        cfg_path = project / ".specify" / "extension-catalogs.yml"
+        cfg_path.write_text(
+            yaml.safe_dump(
+                {
+                    "catalogs": [
+                        {
+                            "name": "drop",
+                            "url": "https://drop.example.com/catalog.json",
+                            "priority": 10,
+                            "install_allowed": False,
+                            "description": "",
+                        },
+                        keep,
+                    ]
+                },
+                sort_keys=False,
+            ),
+            encoding="utf-8",
+        )
+
+        result = self._invoke(["extension", "catalog", "remove", "drop"], project)
+
+        assert result.exit_code == 0, result.output
+        assert "No catalogs remain" not in _normalize_cli_output(result.output)
+        assert yaml.safe_load(cfg_path.read_text(encoding="utf-8")) == {
+            "catalogs": [keep]
+        }