Extend tools/cross/format.py to handle JS too

.github/workflows/lint.yml

@@ -5,6 +5,7 @@ on:
     paths:
       - src/**
       - .clang-format
+      - .prettierc.json
   push:
     branches:
     - main
@@ -24,8 +25,12 @@ jobs:
           chmod +x llvm.sh
           sudo ./llvm.sh 18
           sudo apt-get install -y --no-install-recommends clang-format-18
+          curl -fsSL https://deb.nodesource.com/setup_22.x | sudo bash
+          apt-get install -y nodejs
+          npm i -g prettier
       - name: Lint
         run: |
           python3 ./tools/cross/format.py --check
         env:
           CLANG_FORMAT: clang-format-18
+          PRETTIER: prettier

package.json

@@ -2,7 +2,8 @@
   "name": "@cloudflare/workerd-root",
   "private": true,
   "scripts": {
-    "lint": "eslint types/src"
+    "lint": "eslint types/src",
+    "prettier": "prettier"
   },
   "dependencies": {
     "capnp-ts": "^0.7.0",

tools/cross/format.py

@@ -5,9 +5,16 @@
 import re
 import subprocess
 from argparse import ArgumentParser, Namespace
-from typing import List, Optional
+from typing import List, Optional, Tuple, Set
 
 CLANG_FORMAT = os.environ.get("CLANG_FORMAT", "clang-format")
+PRETTIER = os.environ.get("PRETTIER")
+
+
+if PRETTIER:
+    PRETTIER = [PRETTIER]
+else:
+    PRETTIER = ["npm", "run", "-s", "prettier", "--"]
 
 
 def parse_args() -> Namespace:
@@ -69,16 +76,16 @@ def check_clang_format() -> bool:
         exit(1)
 
 
-def find_cpp_files(dir_path) -> List[str]:
+def find_files_by_exts(dir_path: str, exts: Tuple[str, ...]) -> List[str]:
     files = []
     for root, _, filenames in os.walk(dir_path):
         for filename in filenames:
-            if filename.endswith((".c++", ".h")):
+            if filename.endswith(exts):
                 files.append(os.path.join(root, filename))
     return files
 
 
-def clang_format(files: List[str], check: bool = False):
+def clang_format(files: List[str], check: bool = False) -> None:
     if not files:
         logging.info("No changes to format")
         exit(0)
@@ -93,6 +100,19 @@ def clang_format(files: List[str], check: bool = False):
         subprocess.run([CLANG_FORMAT, "--verbose", "-i"] + files, check=False)
 
 
+def prettier(files: List[str], check: bool = False) -> None:
+    if not files:
+        logging.info("No changes to format")
+        exit(0)
+    if check:
+        result = subprocess.run([*PRETTIER, "--check", *files])
+        if result.returncode != 0 :
+            logging.error("Code has lint. Fix with python ./tools/cross/format.py")
+            exit(1)
+    else:
+        subprocess.run([*PRETTIER, "--write", *files])
+
+
 def git_get_modified_files(
     target: str, source: Optional[str], staged: bool
 ) -> List[str]:
@@ -114,19 +134,39 @@ def git_get_modified_files(
         return files_in_diff
 
 
+def format_cpp(files_in_diff: Optional[Set[str]], check: bool) -> None:
+    cpp_files = set(find_files_by_exts("src/workerd", (".c++", ".h")))
+
+    if files_in_diff:
+        cpp_files &= files_in_diff
+
+    clang_format(list(cpp_files), check)
+
+
+def format_js(files_in_diff: Optional[Set[str]], check: bool) -> None:
+    js_files = set(find_files_by_exts("src", (".js", ".ts", ".json")))
+
+    if files_in_diff:
+        js_files &= files_in_diff
+
+    prettier(list(js_files), check)
+
+
 def main():
     options = parse_args()
     check_clang_format()
-    cpp_files = find_cpp_files("src/workerd")
     if options.subcommand == "git":
-        files_in_diff = git_get_modified_files(
+        files_in_diff = set(git_get_modified_files(
             options.target, options.source, options.staged
-        )
-        cpp_files = list(set(cpp_files) & set(files_in_diff))
+        ))
+    else:
+        files_in_diff = None
 
-    clang_format(cpp_files, options.check)
+
+    format_cpp(files_in_diff, options.check)
+    format_js(files_in_diff, options.check)
 
-    # TODO: lint js, ts, bazel files
+    # TODO: lint bazel files
 
 
 if __name__ == "__main__":