Add support for command-specific configuration sections

README.md

@@ -290,6 +290,7 @@ By default, both `pip-compile` and `pip-sync` will look first
 for a `.pip-tools.toml` file and then in your `pyproject.toml`. You can
 also specify an alternate TOML configuration file with the `--config` option.
 
+It is possible to specify configuration values both globally and command-specific.
 For example, to by default generate `pip` hashes in the resulting
 requirements file output, you can specify in a configuration file:
 
@@ -311,6 +312,28 @@ so the above could also be specified in this format:
 generate_hashes = true
 ```
 
+Configuration defaults specific to `pip-compile` and `pip-sync` can be put beneath
+separate sections. For example, to by default perform a dry-run with `pip-compile`:
+
+```toml
+[tool.pip-tools.compile] # "sync" for pip-sync
+dry-run = true
+```
+
+This does not affect the `pip-sync` command, which also has a `--dry-run` option.
+Note that local settings take preference over the global ones of the same name,
+whenever both are declared, thus this would also make `pip-compile` generate hashes,
+but discard the global dry-run setting:
+
+```toml
+[tool.pip-tools]
+generate-hashes = true
+dry-run = true
+
+[tool.pip-tools.compile]
+dry-run = false
+```
+
 You might be wrapping the `pip-compile` command in another script. To avoid
 confusing consumers of your custom script you can override the update command
 generated at the top of requirements files by setting the

piptools/scripts/compile.py

@@ -68,7 +68,10 @@ def _determine_linesep(
     }[strategy]
 
 
-@click.command(context_settings={"help_option_names": options.help_option_names})
+@click.command(
+    name="pip-compile",
+    context_settings={"help_option_names": options.help_option_names},
+)
 @click.pass_context
 @options.version
 @options.verbose

piptools/scripts/sync.py

@@ -30,7 +30,9 @@
 DEFAULT_REQUIREMENTS_FILE = "requirements.txt"
 
 
-@click.command(context_settings={"help_option_names": options.help_option_names})
+@click.command(
+    name="pip-sync", context_settings={"help_option_names": options.help_option_names}
+)
 @options.version
 @options.ask
 @options.dry_run

piptools/utils.py

@@ -532,7 +532,7 @@ def override_defaults_from_config_file(
     ``None`` is returned if no such file is found.
 
     ``pip-tools`` will use the first config file found, searching in this order:
-    an explicitly given config file, a d``.pip-tools.toml``, a ``pyproject.toml``
+    an explicitly given config file, a ``.pip-tools.toml``, a ``pyproject.toml``
     file. Those files are searched for in the same directory as the requirements
     input file, or the current working directory if requirements come via stdin.
     """
@@ -547,9 +547,9 @@ def override_defaults_from_config_file(
         config_file = Path(value)
 
     config = parse_config_file(ctx, config_file)
-    if config:
-        _validate_config(ctx, config)
-        _assign_config_to_cli_context(ctx, config)
+
+    _validate_config(ctx, config)
+    _assign_config_to_cli_context(ctx, config)
 
     return config_file
 
@@ -678,13 +678,24 @@ def parse_config_file(
             hint=f"Could not parse '{config_file !s}': {value_err !s}",
         )
 
-    # In a TOML file, we expect the config to be under `[tool.pip-tools]`
+    # In a TOML file, we expect the config to be under `[tool.pip-tools]`,
+    # `[tool.pip-tools.compile]` or `[tool.pip-tools.sync]`
     piptools_config: dict[str, Any] = config.get("tool", {}).get("pip-tools", {})
+
+    assert click_context.command.name is not None
+    # TODO: Replace with `str.removeprefix()` once dropped 3.8
+    config_section_name = click_context.command.name[len("pip-") :]
+
+    piptools_config.update(piptools_config.pop(config_section_name, {}))
+    piptools_config.pop("compile", {})
+    piptools_config.pop("sync", {})
+
     piptools_config = _normalize_keys_in_config(piptools_config)
     piptools_config = _invert_negative_bool_options_in_config(
         ctx=click_context,
         config=piptools_config,
     )
+
     return piptools_config
 
 

tests/conftest.py

@@ -501,14 +501,20 @@ def _maker(
         pyproject_param: str,
         new_default: Any,
         config_file_name: str = DEFAULT_CONFIG_FILE_NAMES[0],
+        section: str = "pip-tools",
+        subsection: str | None = None,
     ) -> Path:
         # Create a nested directory structure if config_file_name includes directories
         config_dir = (tmpdir_cwd / config_file_name).parent
         config_dir.mkdir(exist_ok=True, parents=True)
 
         # Make a config file with this one config default override
         config_file = tmpdir_cwd / config_file_name
-        config_to_dump = {"tool": {"pip-tools": {pyproject_param: new_default}}}
+
+        nested_config = {pyproject_param: new_default}
+        if subsection:
+            nested_config = {subsection: nested_config}
+        config_to_dump = {"tool": {section: nested_config}}
         config_file.write_text(tomli_w.dumps(config_to_dump))
         return cast(Path, config_file.relative_to(tmpdir_cwd))
 

tests/test_cli_compile.py

@@ -3562,3 +3562,17 @@ def test_origin_of_extra_requirement_not_written_to_annotations(
         )
         == out.stdout
     )
+
+
+def test_tool_specific_config_option(pip_conf, runner, tmp_path, make_config_file):
+    config_file = make_config_file(
+        "dry-run", True, section="pip-tools", subsection="compile"
+    )
+
+    req_in = tmp_path / "requirements.in"
+    req_in.touch()
+
+    out = runner.invoke(cli, [req_in.as_posix(), "--config", config_file.as_posix()])
+
+    assert out.exit_code == 0
+    assert "Dry-run, so nothing updated" in out.stderr

tests/test_cli_sync.py

@@ -450,3 +450,18 @@ def test_allow_in_config_pip_compile_option(run, runner, tmp_path, make_config_f
 
     assert out.exit_code == 0
     assert "Using pip-tools configuration defaults found" in out.stderr
+
+
+@mock.patch("piptools.sync.run")
+def test_tool_specific_config_option(run, runner, make_config_file):
+    config_file = make_config_file(
+        "dry-run", True, section="pip-tools", subsection="sync"
+    )
+
+    with open(sync.DEFAULT_REQUIREMENTS_FILE, "w") as reqs_txt:
+        reqs_txt.write("six==1.10.0")
+
+    out = runner.invoke(cli, ["--config", config_file.as_posix()])
+
+    assert out.exit_code == 1
+    assert "Would install:" in out.stdout