Add support for --debug

mantoni · Oct 19, 2024 · 5e99a06 · 5e99a06
1 parent 4af421a
commit 5e99a06
Show file tree

Hide file tree

Showing 11 changed files with 369 additions and 65 deletions.
diff --git a/bin/eslint_d.js b/bin/eslint_d.js
@@ -1,11 +1,19 @@
 #!/usr/bin/env node
 
+import debug from 'debug';
 import { loadConfig, removeConfig } from '../lib/config.js';
 import { createResolver } from '../lib/resolver.js';
 import { forwardToDaemon, isAlive } from '../lib/forwarder.js';
 import { launchDaemon, stopDaemon } from '../lib/launcher.js';
 import { filesHash } from '../lib/hash.js';
 
+const is_debug_mode = process.argv.includes('--debug');
+if (is_debug_mode) {
+  debug.enable(
+    process.env.DEBUG || 'eslint_d:*,eslint:*,-eslint:code-path,eslintrc:*'
+  );
+}
+
 const command = process.argv[2];
 
 (async () => {
@@ -40,7 +48,7 @@ const command = process.argv[2];
         await removeConfig(resolver);
       }
 
-      await launchDaemon(resolver, hash);
+      await launchDaemon(resolver, hash, is_debug_mode);
 
       return;
     case 'stop':
@@ -54,7 +62,7 @@ const command = process.argv[2];
       if (config) {
         await stopDaemon(resolver, config);
       }
-      await launchDaemon(resolver, hash);
+      await launchDaemon(resolver, hash, is_debug_mode);
       return;
     case 'status':
       (await import('../lib/status.js')).status(resolver, config);
@@ -65,7 +73,7 @@ const command = process.argv[2];
         config = null;
       }
       if (!config) {
-        config = await launchDaemon(resolver, hash);
+        config = await launchDaemon(resolver, hash, false);
         if (!config) {
           return;
         }

diff --git a/lib/config.js b/lib/config.js
@@ -1,5 +1,8 @@
+import debug from 'debug';
 import fs from 'node:fs/promises';
 
+const log = debug('eslint_d:config');
+
 /**
  * @import { Resolver} from './resolver.js'
  */
@@ -18,6 +21,8 @@ import fs from 'node:fs/promises';
  */
 export async function loadConfig(resolver) {
   const filename = configFile(resolver);
+  log('Reading config from %s', filename);
+
   try {
     let raw = await fs.readFile(filename, 'utf8');
     if (!raw) {
@@ -27,6 +32,7 @@ export async function loadConfig(resolver) {
     const [token, port, pid, hash] = raw.split(' ');
     return { token, port: Number(port), pid: Number(pid), hash };
   } catch {
+    log('Config not found');
     return null;
   }
 }
@@ -36,16 +42,21 @@ export async function loadConfig(resolver) {
  * @param {Config} config
  */
 export async function writeConfig(resolver, config) {
+  const filename = configFile(resolver);
+  log('Writing config to %s', filename);
+
   const { token, port, pid, hash } = config;
-  await fs.writeFile(configFile(resolver), `${token} ${port} ${pid} ${hash}`);
+  await fs.writeFile(filename, `${token} ${port} ${pid} ${hash}`);
 }
 
 /**
  * @param {Resolver} resolver
  */
 export async function removeConfig(resolver) {
+  const filename = configFile(resolver);
+  log('Removing config at %s', filename);
   try {
-    await fs.unlink(configFile(resolver));
+    await fs.unlink(filename);
   } catch {
     // ignore
   }

diff --git a/lib/daemon.js b/lib/daemon.js
@@ -3,6 +3,7 @@ import net from 'node:net';
 import path from 'node:path';
 import crypto from 'node:crypto';
 import { createRequire } from 'node:module';
+import debug from 'debug';
 import { configFile, writeConfig, removeConfig } from './config.js';
 import { createService } from './service.js';
 
@@ -18,6 +19,8 @@ const resolver = {
 };
 const hash = argv[3];
 
+const log = debug('eslint_d:daemon');
+
 const token = crypto.randomBytes(8).toString('hex');
 
 let ppid_interval = null;
@@ -27,29 +30,37 @@ let watcher = null;
 
 let service = createService(resolver, token, shutdown);
 if (idle) {
+  log('Using idle %d', idle);
   service = watchConnection(service, idle * 60000);
 }
-const server = net.createServer({ allowHalfOpen: true }, service);
 
+const server = net.createServer({ allowHalfOpen: true }, service);
 server.listen(0, '127.0.0.1', () => {
   const port = server.address()?.['port'];
+  log('Listening on port %d', port);
   writeConfig(resolver, { token, port, pid: process.pid, hash })
     .then(() => {
       watchConfig();
     })
     .catch((err) => {
+      log('Error writing config: %o', err);
       console.error(`eslint_d: ${err}`);
       shutdown();
     });
 });
 
-process.on('SIGTERM', shutdown);
+process.on('SIGTERM', () => {
+  log('Shutting down due to SIGTERM');
+  shutdown();
+});
 
 if (ppid) {
+  log('Using ppid %d', ppid);
   ppid_interval = setInterval(() => {
     try {
       process.kill(ppid, 0);
     } catch {
+      log('Shutting down due to parent exit');
       shutdown();
     }
   }, 1000);
@@ -61,16 +72,24 @@ fs.readFile(project_pkg, 'utf8', (err, data) => {
     try {
       const { name } = JSON.parse(data);
       if (name) {
-        process.title = `eslint_d - ${name === 'eslint_d' ? 'global' : name}`;
+        setProcessTitle(`eslint_d - ${name === 'eslint_d' ? 'global' : name}`);
         return;
       }
     } catch {
       // Fall through
     }
   }
-  process.title = `eslint_d - ${process.cwd()}`;
+  setProcessTitle(`eslint_d - ${process.cwd()}`);
 });
 
+/**
+ * @param {string} title
+ */
+function setProcessTitle(title) {
+  log('Setting process title to "%s"', process.title);
+  process.title = title;
+}
+
 function shutdown() {
   if (idle_timeout) {
     clearTimeout(idle_timeout);
@@ -84,23 +103,29 @@ function shutdown() {
     watcher.close();
     watcher = null;
   }
-  server.close(() =>
+  server.close((err) => {
+    if (err) {
+      log('Error closing server: %o', err);
+    }
     removeConfig(resolver).then(() => {
+      log('Shutdown complete');
       // eslint-disable-next-line n/no-process-exit
       process.exit(0);
-    })
-  );
+    });
+  });
 }
 
 function watchConfig() {
   watcher = fs
     .watch(configFile(resolver), { persistent: false })
     .on('change', (type) => {
       if (type === 'rename') {
+        log('Shutting down due to config removal');
         shutdown();
       }
     })
     .on('error', (err) => {
+      log('Error watching config: %o', err);
       console.error(`eslint_d: ${err}`);
       shutdown();
     });

diff --git a/lib/forwarder.js b/lib/forwarder.js
@@ -1,3 +1,4 @@
+import debug from 'debug';
 import net from 'node:net';
 import supportsColor from 'supports-color';
 import { removeConfig } from '../lib/config.js';
@@ -12,6 +13,8 @@ import { launchDaemon } from './launcher.js';
 const EXIT_TOKEN_REGEXP = new RegExp(/EXIT([0-9]{3})/);
 const EXIT_TOKEN_LENGTH = 7;
 
+const log = debug('eslint_d:forwarder');
+
 /**
  * @param {Config | null} config
  * @returns {Promise<boolean>}
@@ -29,15 +32,16 @@ export function isAlive(config) {
  */
 export async function forwardCommandToDaemon(config, command) {
   if (!config) {
-    return Promise.reject(new Error('config not found'));
+    return Promise.reject(new Error('Config not found'));
   }
 
   const socket = await connectToDaemon(config);
+  log('Request: %o', { token: config.token, command });
   socket.write(JSON.stringify([config.token, command]));
   socket.end();
 
   return new Promise((resolve, reject) => {
-    socket.on('end', () => resolve()).on('error', (err) => reject(err));
+    socket.on('end', resolve).on('error', reject);
   });
 }
 
@@ -79,15 +83,28 @@ export async function forwardToDaemon(resolver, config) {
     return;
   }
 
+  const color_level = stdout ? stdout.level : 0;
+  const cwd = process.cwd();
+  const DEBUG = process.env.DEBUG || '';
+  log('Request: %o', {
+    token: config.token,
+    command: LINT_COMMAND,
+    color_level,
+    cwd,
+    args: eslint_args,
+    DEBUG
+  });
   const args = [
     config.token,
     LINT_COMMAND,
-    stdout ? stdout.level : 0,
-    process.cwd(),
-    eslint_args
+    color_level,
+    cwd,
+    eslint_args,
+    DEBUG
   ];
   socket.write(JSON.stringify(args));
   if (text) {
+    log('Request stdin: %d', text.length);
     socket.write('\n');
     socket.write(text);
   }
@@ -116,14 +133,17 @@ export async function forwardToDaemon(resolver, config) {
       }
 
       if (!fix_to_stdout) {
-        process.exitCode = Number(match[1]);
+        const exit_code = Number(match[1]);
+        log('Exit %d', exit_code);
+        process.exitCode = exit_code;
         return;
       }
 
       try {
         const { output } = JSON.parse(flushMessage())[0];
         process.stdout.write(output || text);
         // Exit code from eslint is deliberately ignored in this case
+        log('Exit %d', 0);
         process.exitCode = 0;
       } catch (err) {
         process.stdout.write(text);
@@ -144,13 +164,15 @@ export async function forwardToDaemon(resolver, config) {
     try {
       return await connectToDaemon(config);
     } catch (/** @type {any} */ err) {
+      log('Failed to connect %o', err);
+
       if (err['code'] === 'ECONNREFUSED' && retry) {
         await removeConfig(resolver);
         // @ts-expect-error we check for nullability in the line below
         // eslint-disable-next-line require-atomic-updates
         config = await launchDaemon(resolver, config.hash);
         if (!config) {
-          throw new Error('unable to start daemon');
+          throw new Error('Unable to start daemon');
         }
         return createSocket(false);
       }
@@ -182,6 +204,7 @@ export async function forwardToDaemon(resolver, config) {
  * @returns {Promise<net.Socket>}
  */
 function connectToDaemon(config) {
+  log('Connecting to daemon 127.0.0.1:%d', config.port);
   return new Promise((resolve, reject) => {
     const socket = net.connect(config.port, '127.0.0.1');
     socket

diff --git a/lib/forwarder.test.js b/lib/forwarder.test.js
@@ -112,7 +112,22 @@ describe('lib/forwarder', () => {
 
       assert.calledOnceWith(
         socket.write,
-        `["token","${LINT_COMMAND}",${color_level},"the/cwd",[${JSON.stringify(process.argv0)},"eslint_d"]]`
+        `["token","${LINT_COMMAND}",${color_level},"the/cwd",[${JSON.stringify(process.argv0)},"eslint_d"],""]`
+      );
+      assert.calledOnce(socket.end);
+    });
+
+    it('writes DEBUG env to socket', async () => {
+      sinon.replace(process, 'cwd', sinon.fake.returns('the/cwd'));
+      sinon.define(process.env, 'DEBUG', 'eslint_d:*');
+
+      forwardToDaemon(resolver, config);
+      socket.on.getCall(0).callback(); // connect
+      await new Promise(setImmediate);
+
+      assert.calledOnceWith(
+        socket.write,
+        `["token","${LINT_COMMAND}",${color_level},"the/cwd",[${JSON.stringify(process.argv0)},"eslint_d"],"eslint_d:*"]`
       );
       assert.calledOnce(socket.end);
     });
@@ -389,7 +404,7 @@ describe('lib/forwarder', () => {
         assert.calledThrice(socket.write);
         assert.calledWith(
           socket.write,
-          `["token","${LINT_COMMAND}",${color_level},"cwd",[${JSON.stringify(process.argv0)},"eslint_d","--stdin","--fix-dry-run","--format","json","--other","--options"]]`
+          `["token","${LINT_COMMAND}",${color_level},"cwd",[${JSON.stringify(process.argv0)},"eslint_d","--stdin","--fix-dry-run","--format","json","--other","--options"],""]`
         );
         assert.calledWith(socket.write, '\n');
         assert.calledWith(socket.write, 'text from stdin');