tools: improve valid-typeof lint rule

Require that `typeof` comparisons be to string literals.

PR-URL: https://github.com/nodejs/node/pull/37924
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

.eslintrc.js

@@ -307,7 +307,7 @@ module.exports = {
     'template-curly-spacing': 'error',
     'unicode-bom': 'error',
     'use-isnan': 'error',
-    'valid-typeof': 'error',
+    'valid-typeof': ['error', { requireStringLiterals: true }],
 
     // Custom rules from eslint-plugin-node-core
     'node-core/no-unescaped-regexp-dot': 'error',

lib/internal/encoding.js

@@ -64,6 +64,7 @@ function validateDecoder(obj) {
 }
 
 function validateArgument(prop, expected, propName, expectedName) {
+  // eslint-disable-next-line valid-typeof
   if (typeof prop !== expected)
     throw new ERR_INVALID_ARG_TYPE(propName, expectedName, prop);
 }

test/parallel/test-assert-calltracker-report.js

@@ -11,22 +11,16 @@ function foo() {}
 const callsfoo = tracker.calls(foo, 1);
 
 // Ensures that foo was added to the callChecks array.
-if (tracker.report()[0].operator !== 'foo') {
-  process.exit(1);
-}
+assert.strictEqual(tracker.report()[0].operator, 'foo');
 
 callsfoo();
 
 // Ensures that foo was removed from the callChecks array after being called the
 // expected number of times.
-if (typeof tracker.report()[0] === 'undefined') {
-  process.exit(1);
-}
+assert.strictEqual(typeof tracker.report()[0], 'undefined');
 
 callsfoo();
 
 // Ensures that foo was added back to the callChecks array after being called
 // more than the expected number of times.
-if (tracker.report()[0].operator !== 'foo') {
-  process.exit(1);
-}
+assert.strictEqual(tracker.report()[0].operator, 'foo');