feat(prettier): Allow a Prettier instance to be optional (#81)

packages/prettier/index.ts

@@ -44,6 +44,10 @@ export function create(
  */
  prettier?: typeof import('prettier') | undefined;
  getPrettier?: (serviceEnv: ServiceEnvironment) => typeof import('prettier') | undefined,
+ /**
+ * If true, the plugin will not throw an error if it can't load Prettier either through the `prettier`, or `getPrettier` properties or through a normal `import('prettier')`.
+ */
+ allowImportError?: boolean;
  } = {},
  getPrettierConfig = async (filePath: string, prettier: typeof import('prettier'), config?: ResolveConfigOptions) => {
  return await prettier.resolveConfig(filePath, config) ?? {};
@@ -52,16 +56,28 @@ export function create(
  return {
  name: 'prettier',
  create(context): ServicePluginInstance {
+ const languages = options.languages ?? ['html', 'css', 'scss', 'typescript', 'javascript'];
 
- let prettier: typeof import('prettier');
+ let _prettier = options.prettier;
  try {
- prettier = options.prettier
- ?? options.getPrettier?.(context.env)
- ?? require('prettier');
- } catch (e) {
- throw new Error("Could not load Prettier: " + e);
+ if (!_prettier) {
+ if (options.getPrettier) {
+ _prettier = options.getPrettier(context.env);
+ } else {
+ _prettier = require('prettier');
+ }
+ }
+ } catch (error) {
+ if (!options.allowImportError) {
+ throw new Error("Could not load Prettier: ");
+ };
  }
- const languages = options.languages ?? ['html', 'css', 'scss', 'typescript', 'javascript'];
+
+ if (!_prettier) {
+ return {};
+ }
+
+ const prettier = _prettier;
 
  return {
  async provideDocumentFormattingEdits(document, _, formatOptions) {