nodejs · Trott · Jan 5, 2022 · Jan 3, 2022
diff --git a/.eslintrc.js b/.eslintrc.js
@@ -175,6 +175,7 @@ module.exports = {
     }],
     'new-parens': 'error',
     'no-async-promise-executor': 'error',
+    'no-case-declarations': 'error',
     'no-class-assign': 'error',
     'no-confusing-arrow': 'error',
     'no-const-assign': 'error',

diff --git a/benchmark/zlib/inflate.js b/benchmark/zlib/inflate.js
@@ -16,7 +16,7 @@ function main({ n, method, inputLen }) {
   let i = 0;
   switch (method) {
     // Performs `n` single inflate operations
-    case 'inflate':
+    case 'inflate': {
       const inflate = zlib.inflate;
       bench.start();
       (function next(err, result) {
@@ -25,14 +25,16 @@ function main({ n, method, inputLen }) {
         inflate(chunk, next);
       })();
       break;
+    }
     // Performs `n` single inflateSync operations
-    case 'inflateSync':
+    case 'inflateSync': {
       const inflateSync = zlib.inflateSync;
       bench.start();
       for (; i < n; ++i)
         inflateSync(chunk);
       bench.end(n);
       break;
+    }
     default:
       throw new Error('Unsupported inflate method');
   }

diff --git a/lib/_http_server.js b/lib/_http_server.js
@@ -411,7 +411,7 @@ Server.prototype.setTimeout = function setTimeout(msecs, callback) {
 
 Server.prototype[EE.captureRejectionSymbol] = function(err, event, ...args) {
   switch (event) {
-    case 'request':
+    case 'request': {
       const { 1: res } = args;
       if (!res.headersSent && !res.writableEnded) {
         // Don't leak headers.
@@ -425,6 +425,7 @@ Server.prototype[EE.captureRejectionSymbol] = function(err, event, ...args) {
         res.destroy();
       }
       break;
+    }
     default:
       net.Server.prototype[SymbolFor('nodejs.rejection')]
         .apply(this, arguments);

diff --git a/lib/internal/bootstrap/switches/is_main_thread.js b/lib/internal/bootstrap/switches/is_main_thread.js
@@ -42,20 +42,22 @@ function createWritableStdioStream(fd) {
   let stream;
   // Note stream._type is used for test-module-load-list.js
   switch (guessHandleType(fd)) {
-    case 'TTY':
+    case 'TTY': {
       const tty = require('tty');
       stream = new tty.WriteStream(fd);
       stream._type = 'tty';
       break;
+    }
 
-    case 'FILE':
+    case 'FILE': {
       const SyncWriteStream = require('internal/fs/sync_write_stream');
       stream = new SyncWriteStream(fd, { autoClose: false });
       stream._type = 'fs';
       break;
+    }
 
     case 'PIPE':
-    case 'TCP':
+    case 'TCP': {
       const net = require('net');
 
       // If fd is already being used for the IPC channel, libuv will return
@@ -78,8 +80,9 @@ function createWritableStdioStream(fd) {
 
       stream._type = 'pipe';
       break;
+    }
 
-    default:
+    default: {
       // Provide a dummy black-hole output for e.g. non-console
       // Windows applications.
       const { Writable } = require('stream');
@@ -88,6 +91,7 @@ function createWritableStdioStream(fd) {
           cb();
         }
       });
+    }
   }
 
   // For supporting legacy API we put the FD here.
@@ -147,18 +151,20 @@ function getStdin() {
   const fd = 0;
 
   switch (guessHandleType(fd)) {
-    case 'TTY':
+    case 'TTY': {
       const tty = require('tty');
       stdin = new tty.ReadStream(fd);
       break;
+    }
 
-    case 'FILE':
+    case 'FILE': {
       const fs = require('fs');
       stdin = new fs.ReadStream(null, { fd: fd, autoClose: false });
       break;
+    }
 
     case 'PIPE':
-    case 'TCP':
+    case 'TCP': {
       const net = require('net');
 
       // It could be that process has been started with an IPC channel
@@ -183,13 +189,15 @@ function getStdin() {
       // Make sure the stdin can't be `.end()`-ed
       stdin._writableState.ended = true;
       break;
+    }
 
-    default:
+    default: {
       // Provide a dummy contentless input for e.g. non-console
       // Windows applications.
       const { Readable } = require('stream');
       stdin = new Readable({ read() {} });
       stdin.push(null);
+    }
   }
 
   // For supporting legacy API we put the FD here.

diff --git a/lib/internal/crypto/aes.js b/lib/internal/crypto/aes.js
@@ -189,7 +189,7 @@ function asyncAesGcmCipher(
   const tagByteLength = MathFloor(tagLength / 8);
   let tag;
   switch (mode) {
-    case kWebCryptoCipherDecrypt:
+    case kWebCryptoCipherDecrypt: {
       const slice = ArrayBufferIsView(data) ?
         TypedArrayPrototypeSlice : ArrayBufferPrototypeSlice;
       tag = slice(data, -tagByteLength);
@@ -206,6 +206,7 @@ function asyncAesGcmCipher(
 
       data = slice(data, 0, -tagByteLength);
       break;
+    }
     case kWebCryptoCipherEncrypt:
       tag = tagByteLength;
       break;

diff --git a/lib/internal/crypto/webcrypto.js b/lib/internal/crypto/webcrypto.js
@@ -427,7 +427,7 @@ async function importGenericSecretKey(
 
       break;
     }
-    case 'raw':
+    case 'raw': {
       if (hasAnyNotIn(usagesSet, ['deriveKey', 'deriveBits'])) {
         throw lazyDOMException(
           `Unsupported key usage for a ${name} key`,
@@ -449,6 +449,7 @@ async function importGenericSecretKey(
 
       const keyObject = createSecretKey(keyData);
       return new InternalCryptoKey(keyObject, { name }, keyUsages, false);
+    }
   }
 
   throw lazyDOMException(

diff --git a/lib/internal/error_serdes.js b/lib/internal/error_serdes.js
@@ -120,21 +120,23 @@ let deserialize;
 function deserializeError(error) {
   if (!deserialize) deserialize = require('v8').deserialize;
   switch (error[0]) {
-    case kSerializedError:
+    case kSerializedError: {
       const { constructor, properties } = deserialize(error.subarray(1));
       const ctor = errors[constructor];
       ObjectDefineProperty(properties, SymbolToStringTag, {
         value: { value: 'Error', configurable: true },
         enumerable: true
       });
       return ObjectCreate(ctor.prototype, properties);
+    }
     case kSerializedObject:
       return deserialize(error.subarray(1));
-    case kInspectedError:
+    case kInspectedError: {
       const buf = Buffer.from(error.buffer,
                               error.byteOffset + 1,
                               error.byteLength - 1);
       return buf.toString('utf8');
+    }
   }
   require('assert').fail('This should not happen');
 }

diff --git a/lib/internal/http2/compat.js b/lib/internal/http2/compat.js
@@ -217,28 +217,31 @@ const proxySocketHandler = {
       case 'writable':
       case 'destroyed':
         return stream[prop];
-      case 'readable':
+      case 'readable': {
         if (stream.destroyed)
           return false;
         const request = stream[kRequest];
         return request ? request.readable : stream.readable;
-      case 'setTimeout':
+      }
+      case 'setTimeout': {
         const session = stream.session;
         if (session !== undefined)
           return FunctionPrototypeBind(session.setTimeout, session);
         return FunctionPrototypeBind(stream.setTimeout, stream);
+      }
       case 'write':
       case 'read':
       case 'pause':
       case 'resume':
         throw new ERR_HTTP2_NO_SOCKET_MANIPULATION();
-      default:
+      default: {
         const ref = stream.session !== undefined ?
           stream.session[kSocket] : stream;
         const value = ref[prop];
         return typeof value === 'function' ?
           FunctionPrototypeBind(value, ref) :
           value;
+      }
     }
   },
   getPrototypeOf(stream) {
@@ -258,23 +261,25 @@ const proxySocketHandler = {
       case 'destroy':
         stream[prop] = value;
         return true;
-      case 'setTimeout':
+      case 'setTimeout': {
         const session = stream.session;
         if (session !== undefined)
           session.setTimeout = value;
         else
           stream.setTimeout = value;
         return true;
+      }
       case 'write':
       case 'read':
       case 'pause':
       case 'resume':
         throw new ERR_HTTP2_NO_SOCKET_MANIPULATION();
-      default:
+      default: {
         const ref = stream.session !== undefined ?
           stream.session[kSocket] : stream;
         ref[prop] = value;
         return true;
+      }
     }
   }
 };

diff --git a/lib/internal/http2/core.js b/lib/internal/http2/core.js
@@ -867,14 +867,15 @@ const proxySocketHandler = {
       case 'setKeepAlive':
       case 'setNoDelay':
         throw new ERR_HTTP2_NO_SOCKET_MANIPULATION();
-      default:
+      default: {
         const socket = session[kSocket];
         if (socket === undefined)
           throw new ERR_HTTP2_SOCKET_UNBOUND();
         const value = socket[prop];
         return typeof value === 'function' ?
           FunctionPrototypeBind(value, socket) :
           value;
+      }
     }
   },
   getPrototypeOf(session) {
@@ -901,12 +902,13 @@ const proxySocketHandler = {
       case 'setKeepAlive':
       case 'setNoDelay':
         throw new ERR_HTTP2_NO_SOCKET_MANIPULATION();
-      default:
+      default: {
         const socket = session[kSocket];
         if (socket === undefined)
           throw new ERR_HTTP2_SOCKET_UNBOUND();
         socket[prop] = value;
         return true;
+      }
     }
   }
 };
@@ -1558,10 +1560,11 @@ class Http2Session extends EventEmitter {
 
   [EventEmitter.captureRejectionSymbol](err, event, ...args) {
     switch (event) {
-      case 'stream':
+      case 'stream': {
         const stream = args[0];
         stream.destroy(err);
         break;
+      }
       default:
         this.destroy(err);
     }
@@ -3184,7 +3187,7 @@ Http2Server.prototype[EventEmitter.captureRejectionSymbol] = function(
   err, event, ...args) {
 
   switch (event) {
-    case 'stream':
+    case 'stream': {
       // TODO(mcollina): we might want to match this with what we do on
       // the compat side.
       const { 0: stream } = args;
@@ -3195,7 +3198,8 @@ Http2Server.prototype[EventEmitter.captureRejectionSymbol] = function(
         stream.end();
       }
       break;
-    case 'request':
+    }
+    case 'request': {
       const { 1: res } = args;
       if (!res.headersSent && !res.finished) {
         // Don't leak headers.
@@ -3208,6 +3212,7 @@ Http2Server.prototype[EventEmitter.captureRejectionSymbol] = function(
         res.destroy();
       }
       break;
+    }
     default:
       ArrayPrototypeUnshift(args, err, event);
       ReflectApply(net.Server.prototype[EventEmitter.captureRejectionSymbol],

diff --git a/lib/internal/repl/utils.js b/lib/internal/repl/utils.js
@@ -110,14 +110,15 @@ function isRecoverableError(e, code) {
                 recoverable = true;
                 break;
 
-              case 'Unterminated string constant':
+              case 'Unterminated string constant': {
                 const token = StringPrototypeSlice(this.input,
                                                    this.lastTokStart, this.pos);
                 // See https://www.ecma-international.org/ecma-262/#sec-line-terminators
                 if (RegExpPrototypeTest(/\\(?:\r\n?|\n|\u2028|\u2029)$/,
                                         token)) {
                   recoverable = true;
                 }
+              }
             }
             super.raise(pos, message);
           }