Add --generate-cli-command option to generate CLI command from pyproject.toml (#2583)

* Add --generate-cli-command option to generate CLI from pyproject.toml

* docs: update command help in README

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* Improve typing

* Add unitest for _format_cli_value

* Add unitest for _format_cli_value

* update unitest

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* update unitest

---------

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Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Author: 3 people

README.md

@@ -538,6 +538,8 @@ General options:
   --debug               show debug message (require "debug". `$ pip install ''datamodel-code-
                         generator[debug]''`)
   --disable-warnings    disable warnings
+  --generate-cli-command
+                        Generate CLI command from pyproject.toml configuration and exit
   --generate-pyproject-config
                         Generate pyproject.toml configuration from the provided CLI
                         arguments and exit

docs/index.md

@@ -530,6 +530,8 @@ General options:
   --debug               show debug message (require "debug". `$ pip install ''datamodel-code-
                         generator[debug]''`)
   --disable-warnings    disable warnings
+  --generate-cli-command
+                        Generate CLI command from pyproject.toml configuration and exit
   --generate-pyproject-config
                         Generate pyproject.toml configuration from the provided CLI
                         arguments and exit

src/datamodel_code_generator/__main__.py

@@ -60,13 +60,18 @@
 # Options that should be excluded from pyproject.toml config generation
 EXCLUDED_CONFIG_OPTIONS: frozenset[str] = frozenset({
     "generate_pyproject_config",
+    "generate_cli_command",
     "version",
     "help",
     "debug",
     "no_color",
     "disable_warnings",
 })
 
+BOOLEAN_OPTIONAL_OPTIONS: frozenset[str] = frozenset({
+    "use_specialized_enum",
+})
+
 
 class Exit(IntEnum):
     """Exit reasons."""
@@ -487,6 +492,36 @@ def generate_pyproject_config(args: Namespace) -> str:
     return "\n".join(lines) + "\n"
 
 
+def _format_cli_value(value: str | list[str]) -> str:
+    """Format a value for CLI argument."""
+    if isinstance(value, list):
+        return " ".join(f'"{v}"' if " " in v else v for v in value)
+    return f'"{value}"' if " " in value else value
+
+
+def generate_cli_command(config: dict[str, TomlValue]) -> str:
+    """Generate CLI command from pyproject.toml configuration."""
+    parts: list[str] = ["datamodel-codegen"]
+
+    for key, value in sorted(config.items()):
+        if key in EXCLUDED_CONFIG_OPTIONS:
+            continue
+
+        cli_key = key.replace("_", "-")
+
+        if isinstance(value, bool):
+            if value:
+                parts.append(f"--{cli_key}")
+            elif key in BOOLEAN_OPTIONAL_OPTIONS:
+                parts.append(f"--no-{cli_key}")
+        elif isinstance(value, list):
+            parts.extend((f"--{cli_key}", _format_cli_value(cast("list[str]", value))))
+        else:
+            parts.extend((f"--{cli_key}", _format_cli_value(str(value))))
+
+    return " ".join(parts) + "\n"
+
+
 def main(args: Sequence[str] | None = None) -> Exit:  # noqa: PLR0911, PLR0912, PLR0915
     """Execute datamodel code generation from command-line arguments."""
     # add cli completion support
@@ -510,6 +545,17 @@ def main(args: Sequence[str] | None = None) -> Exit:  # noqa: PLR0911, PLR0912,
 
     pyproject_config = _get_pyproject_toml_config(Path.cwd())
 
+    if namespace.generate_cli_command:
+        if not pyproject_config:
+            print(  # noqa: T201
+                "No [tool.datamodel-codegen] section found in pyproject.toml",
+                file=sys.stderr,
+            )
+            return Exit.ERROR
+        command_output = generate_cli_command(pyproject_config)
+        print(command_output)  # noqa: T201
+        return Exit.OK
+
     try:
         config = Config.parse_obj(pyproject_config)
         config.merge_args(namespace)

src/datamodel_code_generator/arguments.py

@@ -664,6 +664,12 @@ def start_section(self, heading: str | None) -> None:
     default=None,
     help="Generate pyproject.toml configuration from the provided CLI arguments and exit",
 )
+general_options.add_argument(
+    "--generate-cli-command",
+    action="store_true",
+    default=None,
+    help="Generate CLI command from pyproject.toml configuration and exit",
+)
 general_options.add_argument(
     "--version",
     action="store_true",

tests/data/expected/main/generate_cli_command/false_boolean.txt

@@ -0,0 +1,2 @@
+datamodel-codegen --input schema.yaml
+

tests/data/expected/main/generate_cli_command/list_option.txt

@@ -0,0 +1,2 @@
+datamodel-codegen --input schema.yaml --strict-types str int
+

tests/data/expected/main/generate_cli_command/no_use_specialized_enum.txt

@@ -0,0 +1,2 @@
+datamodel-codegen --input schema.yaml --no-use-specialized-enum
+

tests/data/expected/main/generate_cli_command/true_boolean.txt

@@ -0,0 +1,2 @@
+datamodel-codegen --input schema.yaml --snake-case-field
+

tests/data/expected/main_kr/generate_cli_command/basic.txt

@@ -0,0 +1,2 @@
+datamodel-codegen --input schema.yaml --output model.py
+

tests/data/expected/main_kr/generate_cli_command/boolean_options.txt

@@ -0,0 +1,2 @@
+datamodel-codegen --collapse-root-models --snake-case-field --use-annotated
+