Add fileExtOverrides option handling for Prettier

Author: nevadaperry

prettier/format/src/index.ts

@@ -1,9 +1,10 @@
 import { workerMain } from "@better-rules-javascript/bazel-worker";
 import { ArgumentParser } from "argparse";
-import { dirname } from "node:path";
+import * as path from "node:path";
 import { pathToFileURL } from "node:url";
 import { Options } from "prettier";
 import { load, resolve } from "./import";
+import { readFile, writeFile } from "node:fs/promises";
 
 interface Args {
   config?: string;
@@ -23,7 +24,7 @@ workerMain(async (a) => {
       : (await resolveConfig(args.config, { config: args.config })) ||
         undefined;
   if (options?.plugins) {
-    const contextUrl = pathToFileURL(dirname(args.config!));
+    const contextUrl = pathToFileURL(path.dirname(args.config!));
     options.plugins = await Promise.all(
       options.plugins.map(async (plugin) => {
         // in theory, should be able to just resolve the path, but for some reason
@@ -37,7 +38,8 @@ workerMain(async (a) => {
       }),
     );
   }
-  const worker = new PrettierWorker(options);
+  const fileExtOverrides = (await require(path.resolve(args.config))).fileExtOverrides;
+  const worker = new PrettierWorker(options, fileExtOverrides);
 
   return async (a) => {
     try {

prettier/format/src/worker.ts

@@ -3,7 +3,10 @@ import { readFile, writeFile } from "node:fs/promises";
 import { Options, format } from "prettier";
 
 export class PrettierWorker {
-  constructor(private readonly options: Options | undefined) {}
+  constructor(
+    readonly options: Options | undefined,
+    readonly fileExtOverrides: { [fileExt: string]: object } | undefined,
+  ) {}
 
   async run(a: string[]) {
     const parser = new ArgumentParser();
@@ -13,6 +16,12 @@ export class PrettierWorker {
     const input = await readFile(args.input, "utf8");
     const output = await format(input, {
       ...this.options,
+      ...Object.assign(
+        {},
+        ...Object.entries(this.fileExtOverrides ?? {})
+          .filter(([fileExt, overrides]) => args.input.endsWith(fileExt))
+          .map(([fileExt, overrides]) => overrides)
+      ),
       filepath: args.input,
     });
     await writeFile(args.output, output, "utf8");