Use prettier's resolveConfig to get widget prettier config

Author: weirdwater

packages/pluggable-widgets-tools/src/typings-generator/index.ts

@@ -4,7 +4,7 @@ import { parseStringPromise } from "xml2js";
 import { PackageXml } from "./PackageXml";
 import { WidgetXml } from "./WidgetXml";
 import { generateForWidget } from "./generate";
-import { formatTypescript } from "../utils/formatting";
+import { formatTypeScript } from "../utils/formatting";
 
 const { mkdir, readFile, stat, writeFile } = promises;
 
@@ -40,7 +40,7 @@ export async function transformPackage(content: string, basePath: string) {
             );
         }
 
-        const formattedContent = await formatTypescript(generatedContent);
+        const formattedContent = await formatTypeScript(generatedContent);
         const resultPath = sourcePath.replace(/(\.xml)?$/, "Props.d.ts");
         await writeFile(join(resultBasePath, resultPath), formattedContent);
     }

packages/pluggable-widgets-tools/src/utils/formatting.ts

@@ -1,23 +1,28 @@
-import { readFileSync, existsSync } from "fs";
+import { readFile } from "fs/promises";
 import { join } from "path";
+import { resolveConfig, format, Options } from "prettier";
 import { cwd } from "process";
-import { format as prettierFormat, Options } from "prettier";
 
-const prettierConfigWidgetPath = join(cwd(), "prettier.config.js");
 const prettierConfigBasePath = join(__dirname, "../../configs/prettier.base.json");
 
-let prettierConfigBase: object;
-if (existsSync(prettierConfigWidgetPath)) {
-    prettierConfigBase = require(prettierConfigWidgetPath);
-} else {
-    prettierConfigBase = JSON.parse(readFileSync(prettierConfigBasePath, "utf-8"));
-}
+let prettierTypescriptConfig: Options | undefined;
+
+/**
+ * Uses prettier to format the given TypeScript sourcecode.
+ * @param source The TypeScript snippet that needs to be formatted
+ */
+export async function formatTypeScript(source: string): Promise<string> {
+    if (prettierTypescriptConfig === undefined) {
+        const fakeFilename = join(cwd(), "./src/widget.ts");
+        // If the widget does not have a prettier config, fall back to packaged base config
+        const prettierConfig =
+            (await resolveConfig(fakeFilename)) ?? JSON.parse(await readFile(prettierConfigBasePath, "utf-8"));
 
-const prettierConfig: Options = {
-    ...prettierConfigBase,
-    parser: "babel-ts"
-};
+        prettierTypescriptConfig = {
+            ...prettierConfig,
+            parser: "babel-ts"
+        };
+    }
 
-export function formatTypescript(source: string): Promise<string> {
-    return prettierFormat(source, prettierConfig);
+    return await format(source, prettierTypescriptConfig);
 }