1const { Buffer } = require("buffer");
2const fs = require("fs");
3const path = require("path");
4const { once } = require("events");
5
6const prettierContainerPath = process.argv[2];
7if (prettierContainerPath == null || prettierContainerPath.length == 0) {
8 process.stderr.write(
9 `Prettier path argument was not specified or empty.\nUsage: ${process.argv[0]} ${process.argv[1]} prettier/path\n`,
10 );
11 process.exit(1);
12}
13fs.stat(prettierContainerPath, (err, stats) => {
14 if (err) {
15 process.stderr.write(`Path '${prettierContainerPath}' does not exist\n`);
16 process.exit(1);
17 }
18
19 if (!stats.isDirectory()) {
20 process.stderr.write(`Path '${prettierContainerPath}' exists but is not a directory\n`);
21 process.exit(1);
22 }
23});
24const prettierPath = path.join(prettierContainerPath, "node_modules/prettier");
25
26class Prettier {
27 constructor(path, prettier, config) {
28 this.path = path;
29 this.prettier = prettier;
30 this.config = config;
31 }
32}
33
34(async () => {
35 let prettier;
36 let config;
37 try {
38 prettier = await loadPrettier(prettierPath);
39 config = (await prettier.resolveConfig(prettierPath)) || {};
40 } catch (e) {
41 process.stderr.write(`Failed to load prettier: ${e}\n`);
42 process.exit(1);
43 }
44 process.stderr.write(`Prettier at path '${prettierPath}' loaded successfully, config: ${JSON.stringify(config)}\n`);
45 process.stdin.resume();
46 handleBuffer(new Prettier(prettierPath, prettier, config));
47})();
48
49async function handleBuffer(prettier) {
50 for await (const messageText of readStdin()) {
51 let message;
52 try {
53 message = JSON.parse(messageText);
54 } catch (e) {
55 sendResponse(makeError(`Parse error in request message: ${e}\nMessage: ${messageText}`));
56 continue;
57 }
58 // allow concurrent request handling by not `await`ing the message handling promise (async function)
59 handleMessage(message, prettier).catch((e) => {
60 if ((message.params || {}).text !== undefined) {
61 message.params.text = "..snip..";
62 }
63 sendResponse({
64 id: message.id,
65 ...makeError(`${e}\nWhile handling prettier request: ${JSON.stringify(message)}`),
66 });
67 });
68 }
69}
70
71const headerSeparator = "\r\n";
72const contentLengthHeaderName = "Content-Length";
73
74async function* readStdin() {
75 let buffer = Buffer.alloc(0);
76 let streamEnded = false;
77 process.stdin.on("end", () => {
78 streamEnded = true;
79 });
80 process.stdin.on("data", (data) => {
81 buffer = Buffer.concat([buffer, data]);
82 });
83
84 async function handleStreamEnded(errorMessage) {
85 sendResponse(makeError(errorMessage));
86 buffer = Buffer.alloc(0);
87 messageLength = null;
88 await once(process.stdin, "readable");
89 streamEnded = false;
90 }
91
92 try {
93 let headersLength = null;
94 let messageLength = null;
95 main_loop: while (true) {
96 if (messageLength === null) {
97 while (buffer.indexOf(`${headerSeparator}${headerSeparator}`) === -1) {
98 if (streamEnded) {
99 await handleStreamEnded("Unexpected end of stream: headers not found");
100 continue main_loop;
101 } else if (buffer.length > contentLengthHeaderName.length * 10) {
102 await handleStreamEnded(
103 `Unexpected stream of bytes: no headers end found after ${buffer.length} bytes of input`,
104 );
105 continue main_loop;
106 }
107 await once(process.stdin, "readable");
108 }
109 const headers = buffer.subarray(0, buffer.indexOf(`${headerSeparator}${headerSeparator}`)).toString("ascii");
110 const contentLengthHeader = headers
111 .split(headerSeparator)
112 .map((header) => header.split(":"))
113 .filter((header) => header[2] === undefined)
114 .filter((header) => (header[1] || "").length > 0)
115 .find((header) => (header[0] || "").trim() === contentLengthHeaderName);
116 const contentLength = (contentLengthHeader || [])[1];
117 if (contentLength === undefined) {
118 await handleStreamEnded(`Missing or incorrect ${contentLengthHeaderName} header: ${headers}`);
119 continue main_loop;
120 }
121 headersLength = headers.length + headerSeparator.length * 2;
122 messageLength = parseInt(contentLength, 10);
123 }
124
125 while (buffer.length < headersLength + messageLength) {
126 if (streamEnded) {
127 await handleStreamEnded(
128 `Unexpected end of stream: buffer length ${buffer.length} does not match expected header length ${headersLength} + body length ${messageLength}`,
129 );
130 continue main_loop;
131 }
132 await once(process.stdin, "readable");
133 }
134
135 const messageEnd = headersLength + messageLength;
136 const message = buffer.subarray(headersLength, messageEnd);
137 buffer = buffer.subarray(messageEnd);
138 headersLength = null;
139 messageLength = null;
140 yield message.toString("utf8");
141 }
142 } catch (e) {
143 sendResponse(makeError(`Error reading stdin: ${e}`));
144 } finally {
145 process.stdin.off("data", () => {});
146 }
147}
148
149async function handleMessage(message, prettier) {
150 const { method, id, params } = message;
151 if (method === undefined) {
152 throw new Error(`Message method is undefined: ${JSON.stringify(message)}`);
153 } else if (method == "initialized") {
154 return;
155 } else if (method === "shutdown") {
156 sendResponse({ result: {} });
157 } else if (method == "exit") {
158 process.exit(0);
159 }
160
161 if (id === undefined) {
162 throw new Error(`Message id is undefined: ${JSON.stringify(message)}`);
163 }
164
165 if (method === "prettier/format") {
166 if (params === undefined || params.text === undefined) {
167 throw new Error(`Message params.text is undefined: ${JSON.stringify(message)}`);
168 }
169 if (params.options === undefined) {
170 throw new Error(`Message params.options is undefined: ${JSON.stringify(message)}`);
171 }
172
173 let resolvedConfig = {};
174 if (params.options.filepath) {
175 resolvedConfig = (await prettier.prettier.resolveConfig(params.options.filepath)) || {};
176
177 if (params.options.ignorePath) {
178 const fileInfo = await prettier.prettier.getFileInfo(params.options.filepath, {
179 ignorePath: params.options.ignorePath,
180 });
181 if (fileInfo.ignored) {
182 process.stderr.write(
183 `Ignoring file '${params.options.filepath}' based on rules in '${params.options.ignorePath}'\n`,
184 );
185 sendResponse({ id, result: { text: params.text } });
186 return;
187 }
188 }
189 }
190
191 // Marking the params.options.filepath as undefined makes
192 // prettier.format() work even if no filepath is set.
193 if (params.options.filepath === null) {
194 params.options.filepath = undefined;
195 }
196
197 const plugins =
198 Array.isArray(resolvedConfig?.plugins) && resolvedConfig.plugins.length > 0
199 ? resolvedConfig.plugins
200 : params.options.plugins;
201
202 const options = {
203 ...(params.options.prettierOptions || prettier.config),
204 ...resolvedConfig,
205 plugins,
206 parser: params.options.parser,
207 filepath: params.options.filepath,
208 };
209 process.stderr.write(
210 `Resolved config: ${JSON.stringify(resolvedConfig)}, will format file '${
211 params.options.filepath || ""
212 }' with options: ${JSON.stringify(options)}\n`,
213 );
214 const formattedText = await prettier.prettier.format(params.text, options);
215 sendResponse({ id, result: { text: formattedText } });
216 } else if (method === "prettier/clear_cache") {
217 prettier.prettier.clearConfigCache();
218 prettier.config = (await prettier.prettier.resolveConfig(prettier.path)) || {};
219 sendResponse({ id, result: null });
220 } else if (method === "initialize") {
221 sendResponse({
222 id,
223 result: {
224 capabilities: {},
225 },
226 });
227 } else {
228 throw new Error(`Unknown method: ${method}`);
229 }
230}
231
232function makeError(message) {
233 return {
234 error: {
235 code: -32600, // invalid request code
236 message,
237 },
238 };
239}
240
241function sendResponse(response) {
242 const responsePayloadString = JSON.stringify({
243 jsonrpc: "2.0",
244 ...response,
245 });
246 const headers = `${contentLengthHeaderName}: ${Buffer.byteLength(
247 responsePayloadString,
248 )}${headerSeparator}${headerSeparator}`;
249 process.stdout.write(headers + responsePayloadString);
250}
251
252function loadPrettier(prettierPath) {
253 return new Promise((resolve, reject) => {
254 fs.access(prettierPath, fs.constants.F_OK, (err) => {
255 if (err) {
256 reject(`Path '${prettierPath}' does not exist.Error: ${err}`);
257 } else {
258 try {
259 resolve(require(prettierPath));
260 } catch (err) {
261 reject(`Error requiring prettier module from path '${prettierPath}'.Error: ${err}`);
262 }
263 }
264 });
265 });
266}