feat: Add host CLI option as alternative to config

src/blueapi/cli/cli.py

@@ -80,11 +80,12 @@ def is_str_dict(val: Any) -> TypeGuard[TaskParameters]:
     invoke_without_command=True, context_settings={"auto_envvar_prefix": "BLUEAPI"}
 )
 @click.version_option(version=__version__, prog_name="blueapi")
+@click.option("-H", "--host", type=str)
 @click.option(
     "-c", "--config", type=Path, help="Path to configuration YAML file", multiple=True
 )
 @click.pass_context
-def main(ctx: click.Context, config: tuple[Path, ...]) -> None:
+def main(ctx: click.Context, config: tuple[Path, ...], host: str | None):
     # if no command is supplied, run with the options passed
 
     # Set umask to DLS standard
@@ -95,6 +96,8 @@ def main(ctx: click.Context, config: tuple[Path, ...]) -> None:
         config_loader.use_values_from_yaml(*config)
     except FileNotFoundError as fnfe:
         raise ClickException(f"Config file not found: {fnfe.filename}") from fnfe
+    if host:
+        config_loader.use_values({"api": {"url": host}})
 
     loaded_config: ApplicationConfig = config_loader.load()
 

tests/unit_tests/cli/test_cli.py

@@ -1384,3 +1384,45 @@ def test_config_schema(
 def test_task_parameter_type(value, result):
     t = ParametersType()
     assert t.convert(value, None, None) == result
+
+
+@responses.activate
+def test_host_option(runner: CliRunner):
+    response = responses.add(
+        responses.GET,
+        "http://override.example.com:5678/plans",
+        json={"plans": []},
+        status=200,
+    )
+
+    res = runner.invoke(
+        main,
+        ["--host", "http://override.example.com:5678", "controller", "plans"],
+    )
+    assert response.call_count == 1
+    assert res.exit_code == 0
+
+
+@responses.activate
+def test_host_overrides_config(runner: CliRunner):
+    config_path = "tests/unit_tests/example_yaml/rest_config.yaml"
+    response = responses.add(
+        responses.GET,
+        "http://override.example.com:5678/plans",
+        json={"plans": []},
+        status=200,
+    )
+
+    res = runner.invoke(
+        main,
+        [
+            "--host",
+            "http://override.example.com:5678",
+            "--config",
+            config_path,
+            "controller",
+            "plans",
+        ],
+    )
+    assert response.call_count == 1
+    assert res.exit_code == 0