Update rule-generation scripts to match latest conventions (#1758)

Resolves #1755.

scripts/add_rule.py

@@ -0,0 +1,172 @@
+#!/usr/bin/env python3
+"""Generate boilerplate for a new rule.
+
+Example usage:
+
+    python scripts/add_rule.py \
+        --name PreferListBuiltin \
+        --code PIE807 \
+        --origin flake8-pie
+"""
+
+import argparse
+import os
+
+ROOT_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+
+
+def dir_name(origin: str) -> str:
+    return origin.replace("-", "_")
+
+
+def pascal_case(origin: str) -> str:
+    """Convert from snake-case to PascalCase."""
+    return "".join(word.title() for word in origin.split("-"))
+
+
+def snake_case(name: str) -> str:
+    """Convert from PascalCase to snake_case."""
+    return "".join(f"_{word.lower()}" if word.isupper() else word for word in name).lstrip("_")
+
+
+def main(*, name: str, code: str, origin: str) -> None:
+    # Create a test fixture.
+    with open(
+        os.path.join(ROOT_DIR, f"resources/test/fixtures/{dir_name(origin)}/{code}.py"),
+        "a",
+    ):
+        pass
+
+    # Add the relevant `#testcase` macro.
+    with open(os.path.join(ROOT_DIR, f"src/{dir_name(origin)}/mod.rs")) as fp:
+        content = fp.read()
+
+    with open(os.path.join(ROOT_DIR, f"src/{dir_name(origin)}/mod.rs"), "w") as fp:
+        for line in content.splitlines():
+            if line.strip() == "fn rules(rule_code: RuleCode, path: &Path) -> Result<()> {":
+                indent = line.split("fn rules(rule_code: RuleCode, path: &Path) -> Result<()> {")[0]
+                fp.write(f'{indent}#[test_case(RuleCode::{code}, Path::new("{code}.py"); "{code}")]')
+                fp.write("\n")
+
+            fp.write(line)
+            fp.write("\n")
+
+    # Add the relevant rule function.
+    with open(os.path.join(ROOT_DIR, f"src/{dir_name(origin)}/rules.rs"), "a") as fp:
+        fp.write(
+            f"""
+/// {code}
+pub fn {snake_case(name)}(checker: &mut Checker) {{}}
+"""
+        )
+        fp.write("\n")
+
+    # Add the relevant struct to `src/violations.rs`.
+    with open(os.path.join(ROOT_DIR, "src/violations.rs")) as fp:
+        content = fp.read()
+
+    with open(os.path.join(ROOT_DIR, "src/violations.rs"), "w") as fp:
+        for line in content.splitlines():
+            fp.write(line)
+            fp.write("\n")
+
+            if line.startswith(f"// {origin}"):
+                fp.write(
+                    """define_violation!(
+    pub struct %s;
+);
+impl Violation for %s {
+    fn message(&self) -> String {
+        todo!("Implement message")
+    }
+
+    fn placeholder() -> Self {
+        %s
+    }
+}
+"""
+                    % (name, name, name)
+                )
+                fp.write("\n")
+
+    # Add the relevant code-to-violation pair to `src/registry.rs`.
+    with open(os.path.join(ROOT_DIR, "src/registry.rs")) as fp:
+        content = fp.read()
+
+    seen_macro = False
+    has_written = False
+    with open(os.path.join(ROOT_DIR, "src/registry.rs"), "w") as fp:
+        for line in content.splitlines():
+            fp.write(line)
+            fp.write("\n")
+
+            if has_written:
+                continue
+
+            if line.startswith("define_rule_mapping!"):
+                seen_macro = True
+                continue
+
+            if not seen_macro:
+                continue
+
+            if line.strip() == f"// {origin}":
+                indent = line.split("//")[0]
+                fp.write(f"{indent}{code} => violations::{name},")
+                fp.write("\n")
+                has_written = True
+
+    # Add the relevant code-to-origin pair to `src/registry.rs`.
+    with open(os.path.join(ROOT_DIR, "src/registry.rs")) as fp:
+        content = fp.read()
+
+    seen_impl = False
+    has_written = False
+    with open(os.path.join(ROOT_DIR, "src/registry.rs"), "w") as fp:
+        for line in content.splitlines():
+            fp.write(line)
+            fp.write("\n")
+
+            if has_written:
+                continue
+
+            if line.startswith("impl RuleCode"):
+                seen_impl = True
+                continue
+
+            if not seen_impl:
+                continue
+
+            if line.strip() == f"// {origin}":
+                indent = line.split("//")[0]
+                fp.write(f"{indent}RuleCode::{code} => RuleOrigin::{pascal_case(origin)},")
+                fp.write("\n")
+                has_written = True
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser(
+        description="Generate boilerplate for a new rule.",
+        epilog="python scripts/add_rule.py --name PreferListBuiltin --code PIE807 --origin flake8-pie",
+    )
+    parser.add_argument(
+        "--name",
+        type=str,
+        required=True,
+        help="The name of the check to generate, in PascalCase (e.g., 'LineTooLong').",
+    )
+    parser.add_argument(
+        "--code",
+        type=str,
+        required=True,
+        help="The code of the check to generate (e.g., 'A001').",
+    )
+    parser.add_argument(
+        "--origin",
+        type=str,
+        required=True,
+        help="The source with which the check originated (e.g., 'flake8-builtins').",
+    )
+    args = parser.parse_args()
+
+    main(name=args.name, code=args.code, origin=args.origin)