configure/build: Support user-specified application configuration

Add an option `--app-config` to `configure` and `compile`, to allow
users to specify an application configuration file. If unspecified,
mbed-tools will use `mbed_app.json` if the latter exists.

Tests are provided.

Fixes #291

Author: LDong-Arm

news/291.bugfix

@@ -0,0 +1 @@
+Add an option `--app-config` to `configure` and `build` commands to allow users to specify an application configuration file.

src/mbed_tools/cli/build.py

@@ -40,6 +40,9 @@
 @click.option(
     "--custom-targets-json", type=click.Path(), default=None, help="Path to custom_targets.json.",
 )
+@click.option(
+    "--app-config", type=click.Path(), default=None, help="Path to application configuration file.",
+)
 @click.option(
     "-f", "--flash", is_flag=True, default=False, help="Flash the binary onto a device",
 )
@@ -63,6 +66,7 @@ def build(
     baudrate: int,
     mbed_os_path: str,
     custom_targets_json: str,
+    app_config: str,
 ) -> None:
     """Configure and build an Mbed project using CMake and Ninja.
 
@@ -76,6 +80,7 @@ def build(
        custom_targets_json: Path to custom_targets.json.
        toolchain: The toolchain to use for the build.
        mbed_target: The name of the Mbed target to build for.
+       app_config: the path to the application configuration file
        clean: Perform a clean build.
        flash: Flash the binary onto a device.
        sterm: Open a serial terminal to the connected target.
@@ -95,6 +100,8 @@ def build(
     click.echo("Configuring project and generating build system...")
     if custom_targets_json is not None:
         program.files.custom_targets_json = pathlib.Path(custom_targets_json)
+    if app_config is not None:
+        program.files.app_config_file = pathlib.Path(app_config)
     config, _ = generate_config(mbed_target.upper(), toolchain, program)
     generate_build_system(program.root, build_tree, profile)
 

src/mbed_tools/cli/configure.py

@@ -36,8 +36,17 @@
 @click.option(
     "--mbed-os-path", type=click.Path(), default=None, help="Path to local Mbed OS directory.",
 )
+@click.option(
+    "--app-config", type=click.Path(), default=None, help="Path to application configuration file.",
+)
 def configure(
-    toolchain: str, mbed_target: str, program_path: str, mbed_os_path: str, output_dir: str, custom_targets_json: str
+    toolchain: str,
+    mbed_target: str,
+    program_path: str,
+    mbed_os_path: str,
+    output_dir: str,
+    custom_targets_json: str,
+    app_config: str
 ) -> None:
     """Exports a mbed_config.cmake file to build directory in the program root.
 
@@ -55,6 +64,7 @@ def configure(
         program_path: the path to the local Mbed program
         mbed_os_path: the path to the local Mbed OS directory
         output_dir: the path to the output directory
+        app_config: the path to the application configuration file
     """
     cmake_build_subdir = pathlib.Path(mbed_target.upper(), "develop", toolchain.upper())
     if mbed_os_path is None:
@@ -65,6 +75,8 @@ def configure(
         program.files.custom_targets_json = pathlib.Path(custom_targets_json)
     if output_dir is not None:
         program.files.cmake_build_dir = pathlib.Path(output_dir)
+    if app_config is not None:
+        program.files.app_config_file = pathlib.Path(app_config)
 
     mbed_target = mbed_target.upper()
     _, output_path = generate_config(mbed_target, toolchain, program)

tests/cli/test_build.py

@@ -171,6 +171,21 @@ def test_custom_targets_location_used_when_passed(
             generate_config.assert_called_once_with(target.upper(), toolchain.upper(), program)
             self.assertEqual(program.files.custom_targets_json, custom_targets_json_path)
 
+    def test_app_config_used_when_passed(
+        self, generate_config, mbed_program, build_project, generate_build_system
+    ):
+        program = mbed_program.from_existing()
+        with mock_project_directory(program, mbed_config_exists=True, build_tree_exists=True):
+            toolchain = "gcc_arm"
+            target = "k64f"
+            app_config_path = pathlib.Path("alternative_config.json")
+
+            runner = CliRunner()
+            runner.invoke(build, ["-t", toolchain, "-m", target, "--app-config", app_config_path])
+
+            generate_config.assert_called_once_with(target.upper(), toolchain.upper(), program)
+            self.assertEqual(program.files.app_config_file, app_config_path)
+
     def test_build_folder_removed_when_clean_flag_passed(
         self, generate_config, mbed_program, build_project, generate_build_system
     ):

tests/cli/test_configure.py

@@ -47,3 +47,15 @@ def test_custom_output_directory_used_when_passed(self, program, generate_config
 
         generate_config.assert_called_once_with("K64F", "GCC_ARM", program)
         self.assertEqual(program.files.cmake_build_dir, output_dir)
+
+    @mock.patch("mbed_tools.cli.configure.generate_config")
+    @mock.patch("mbed_tools.cli.configure.MbedProgram")
+    def test_app_config_used_when_passed(self, program, generate_config):
+        program = program.from_existing()
+        app_config_path = pathlib.Path("alternative_config.json")
+        CliRunner().invoke(
+            configure, ["-t", "gcc_arm", "-m", "k64f", "--app-config", app_config_path]
+        )
+
+        generate_config.assert_called_once_with("K64F", "GCC_ARM", program)
+        self.assertEqual(program.files.app_config_file, app_config_path)