fix(required_arg_missing): suppress Click/Typer CLI command FPs

@click.command(), @click.group(), and @app.command() decorated functions
have their arguments injected from sys.argv by the framework. Calling
main() with no args at the __main__ entry point is correct — not a
missing required argument. Extends the existing pytest.fixture suppression
pattern to CLI command decorators.

Regression: ray-project/ray CI automation scripts (16 FPs).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: Your Name

extractor.py

@@ -55,6 +55,7 @@ class FunctionManifest:
     module_path: str
     args: list[ArgConstraint] = field(default_factory=list)
     is_pytest_fixture: bool = False  # True when decorated with @pytest.fixture
+    is_click_command: bool = False   # True when decorated with @click.command/group or @app.command
 
     @property
     def required_args(self) -> list[ArgConstraint]:
@@ -374,7 +375,20 @@ def _is_fixture_dec(dec: ast.expr) -> bool:
                 return _is_fixture_dec(dec.func)
             return False
 
+        # Detect Click/Typer CLI decorators: @click.command(), @click.group(),
+        # @app.command(), @typer.command() — the framework injects CLI args,
+        # so calling these functions with no args is correct.
+        def _is_click_dec(dec: ast.expr) -> bool:
+            if isinstance(dec, ast.Call):
+                return _is_click_dec(dec.func)
+            if isinstance(dec, ast.Attribute):
+                return dec.attr in ("command", "group")
+            if isinstance(dec, ast.Name):
+                return dec.id in ("command", "group")
+            return False
+
         is_fixture = any(_is_fixture_dec(d) for d in node.decorator_list)
+        is_click = any(_is_click_dec(d) for d in node.decorator_list)
 
         qual = ".".join(self._class_stack + [node.name])
         self.functions.append(
@@ -385,6 +399,7 @@ def _is_fixture_dec(dec: ast.expr) -> bool:
                 module_path=self.module_path,
                 args=constraints,
                 is_pytest_fixture=is_fixture,
+                is_click_command=is_click,
             )
         )
         self.generic_visit(node)

failure_mode.py

@@ -468,6 +468,10 @@ def _check_required_arg(
     # (often a factory), not the fixture function itself.
     if func.is_pytest_fixture:
         return []
+    # Click/Typer CLI commands: the decorator replaces the function so that
+    # calling main() with no args reads from sys.argv. Not a missing-arg bug.
+    if func.is_click_command:
+        return []
     # Only non-kwonly required args can be covered by positional args.
     # Enumerate positional-only required args separately so a kwonly arg at
     # index i is never falsely marked covered because positional_count > i.

test_checker.py

@@ -1969,3 +1969,49 @@ def aggregate(df, key_cols):
     violations = check_codebase(tmp_path)
     od = [v for v in violations if v.context == "optional_dereference" and "pandas_agg.py" in v.file]
     assert len(od) == 0, f"Expected 0 violations for pandas groupby.first(), got {len(od)}: {[(v.line, v.call) for v in od]}"
+
+
+def test_click_command_no_args_not_flagged(tmp_path):
+    """@click.command() decorated functions get args from CLI — calling main() with no args is correct."""
+    _write_src(
+        tmp_path,
+        "cli_tool.py",
+        """
+        import click
+
+        @click.command()
+        @click.option("--name", required=True)
+        @click.option("--count", required=True, type=int)
+        def main(name: str, count: int) -> None:
+            for _ in range(count):
+                print(name)
+
+        if __name__ == "__main__":
+            main()
+        """,
+    )
+    violations = check_codebase(tmp_path)
+    ra = [v for v in violations if v.context == "required_arg_missing" and "cli_tool.py" in v.file]
+    assert len(ra) == 0, f"Expected 0 required_arg_missing for @click.command(), got {len(ra)}: {[(v.line, v.call) for v in ra]}"
+
+
+def test_app_command_no_args_not_flagged(tmp_path):
+    """@app.command() (Typer/Click group) decorated functions should not be flagged."""
+    _write_src(
+        tmp_path,
+        "typer_tool.py",
+        """
+        import typer
+        app = typer.Typer()
+
+        @app.command()
+        def deploy(env: str, force: bool = False) -> None:
+            pass
+
+        if __name__ == "__main__":
+            app()
+        """,
+    )
+    violations = check_codebase(tmp_path)
+    ra = [v for v in violations if v.context == "required_arg_missing" and "typer_tool.py" in v.file]
+    assert len(ra) == 0, f"Expected 0 required_arg_missing for @app.command(), got {len(ra)}: {[(v.line, v.call) for v in ra]}"