tools: enable no-unused-expressions lint rule

Fixes: #36246

PR-URL: #36248
Reviewed-By: Antoine du Hamel <[email protected]>
Reviewed-By: Colin Ihrig <[email protected]>
Reviewed-By: Joyee Cheung <[email protected]>
Reviewed-By: Luigi Pinca <[email protected]>
Reviewed-By: Yongsheng Zhang <[email protected]>
Reviewed-By: Rich Trott <[email protected]>
Reviewed-By: James M Snell <[email protected]>

Author: targos

.eslintrc.js

@@ -234,6 +234,7 @@ module.exports = {
     'no-unreachable': 'error',
     'no-unsafe-finally': 'error',
     'no-unsafe-negation': 'error',
+    'no-unused-expressions': ['error', { allowShortCircuit: true }],
     'no-unused-labels': 'error',
     'no-unused-vars': ['error', { args: 'none', caughtErrors: 'all' }],
     'no-use-before-define': ['error', {

benchmark/_benchmark_progress.js

@@ -39,7 +39,6 @@ class BenchmarkProgress {
     this.completedConfig = 0;
     // Total number of configurations for the current file
     this.scheduledConfig = 0;
-    this.interval;  // Updates the elapsed time.
   }
 
   startQueue(index) {

benchmark/es/destructuring-bench.js

@@ -12,7 +12,8 @@ function runSwapManual(n) {
   let x, y, r;
   bench.start();
   for (let i = 0; i < n; i++) {
-    x = 1, y = 2;
+    x = 1;
+    y = 2;
     r = x;
     x = y;
     y = r;
@@ -26,7 +27,8 @@ function runSwapDestructured(n) {
   let x, y;
   bench.start();
   for (let i = 0; i < n; i++) {
-    x = 1, y = 2;
+    x = 1;
+    y = 2;
     [x, y] = [y, x];
     assert.strictEqual(x, 2);
     assert.strictEqual(y, 1);

benchmark/perf_hooks/bench-eventlooputil.js

@@ -33,7 +33,7 @@ function main({ method, n }) {
 function benchIdleTime(n) {
   bench.start();
   for (let i = 0; i < n; i++)
-    nodeTiming.idleTime;
+    nodeTiming.idleTime; // eslint-disable-line no-unused-expressions
   bench.end(n);
 }
 

benchmark/process/bench-env.js

@@ -13,7 +13,7 @@ function main({ n, operation }) {
     case 'get':
       bench.start();
       for (let i = 0; i < n; i++) {
-        process.env.PATH;
+        process.env.PATH; // eslint-disable-line no-unused-expressions
       }
       bench.end(n);
       break;
@@ -42,7 +42,7 @@ function main({ n, operation }) {
     case 'query':
       bench.start();
       for (let i = 0; i < n; i++) {
-        'PATH' in process.env;
+        'PATH' in process.env; // eslint-disable-line no-unused-expressions
       }
       bench.end(n);
       break;

benchmark/string_decoder/string-decoder-create.js

@@ -12,8 +12,7 @@ const bench = common.createBenchmark(main, {
 function main({ encoding, n }) {
   bench.start();
   for (let i = 0; i < n; ++i) {
-    const sd = new StringDecoder(encoding);
-    !!sd.encoding;
+    new StringDecoder(encoding);
   }
   bench.end(n);
 }

doc/.eslintrc.yaml

@@ -4,6 +4,7 @@ rules:
   # ease some restrictions in doc examples
   no-restricted-properties: off
   no-undef: off
+  no-unused-expressions: off
   no-unused-vars: off
   symbol-description: off
 

lib/internal/assert/assertion_error.js

@@ -455,7 +455,7 @@ class AssertionError extends Error {
     }
     ErrorCaptureStackTrace(this, stackStartFn || stackStartFunction);
     // Create error message including the error code in the name.
-    this.stack;
+    this.stack; // eslint-disable-line no-unused-expressions
     // Reset the name.
     this.name = 'AssertionError';
   }

lib/internal/buffer.js

@@ -952,18 +952,18 @@ function writeFloatBackwards(val, offset = 0) {
 class FastBuffer extends Uint8Array {}
 
 function addBufferPrototypeMethods(proto) {
-  proto.readBigUInt64LE = readBigUInt64LE,
-  proto.readBigUInt64BE = readBigUInt64BE,
-  proto.readBigUint64LE = readBigUInt64LE,
-  proto.readBigUint64BE = readBigUInt64BE,
-  proto.readBigInt64LE = readBigInt64LE,
-  proto.readBigInt64BE = readBigInt64BE,
-  proto.writeBigUInt64LE = writeBigUInt64LE,
-  proto.writeBigUInt64BE = writeBigUInt64BE,
-  proto.writeBigUint64LE = writeBigUInt64LE,
-  proto.writeBigUint64BE = writeBigUInt64BE,
-  proto.writeBigInt64LE = writeBigInt64LE,
-  proto.writeBigInt64BE = writeBigInt64BE,
+  proto.readBigUInt64LE = readBigUInt64LE;
+  proto.readBigUInt64BE = readBigUInt64BE;
+  proto.readBigUint64LE = readBigUInt64LE;
+  proto.readBigUint64BE = readBigUInt64BE;
+  proto.readBigInt64LE = readBigInt64LE;
+  proto.readBigInt64BE = readBigInt64BE;
+  proto.writeBigUInt64LE = writeBigUInt64LE;
+  proto.writeBigUInt64BE = writeBigUInt64BE;
+  proto.writeBigUint64LE = writeBigUInt64LE;
+  proto.writeBigUint64BE = writeBigUInt64BE;
+  proto.writeBigInt64LE = writeBigInt64LE;
+  proto.writeBigInt64BE = writeBigInt64BE;
 
   proto.readUIntLE = readUIntLE;
   proto.readUInt32LE = readUInt32LE;

lib/internal/errors.js

@@ -332,7 +332,7 @@ function addCodeToName(err, name, code) {
   err.name = `${name} [${code}]`;
   // Access the stack to generate the error message including the error code
   // from the name.
-  err.stack;
+  err.stack; // eslint-disable-line no-unused-expressions
   // Reset the name to the actual name.
   if (name === 'SystemError') {
     ObjectDefineProperty(err, 'name', {
@@ -1411,11 +1411,11 @@ E('ERR_TLS_CERT_ALTNAME_INVALID', function(reason, host, cert) {
 }, Error);
 E('ERR_TLS_DH_PARAM_SIZE', 'DH parameter size %s is less than 2048', Error);
 E('ERR_TLS_HANDSHAKE_TIMEOUT', 'TLS handshake timeout', Error);
-E('ERR_TLS_INVALID_CONTEXT', '%s must be a SecureContext', TypeError),
-E('ERR_TLS_INVALID_STATE', 'TLS socket connection must be securely established',
-  Error),
+E('ERR_TLS_INVALID_CONTEXT', '%s must be a SecureContext', TypeError);
 E('ERR_TLS_INVALID_PROTOCOL_VERSION',
   '%j is not a valid %s TLS protocol version', TypeError);
+E('ERR_TLS_INVALID_STATE', 'TLS socket connection must be securely established',
+  Error);
 E('ERR_TLS_PROTOCOL_VERSION_CONFLICT',
   'TLS protocol version %j conflicts with secureProtocol %j', TypeError);
 E('ERR_TLS_RENEGOTIATION_DISABLED',