lib: improve the coverage of the validator

lib/internal/validators.js

@@ -82,10 +82,10 @@ const validateInteger = hideStackFrames(
 const validateInt32 = hideStackFrames(
   (value, name, min = -2147483648, max = 2147483647) => {
     // The defaults for min and max correspond to the limits of 32-bit integers.
+    if (typeof value !== 'number') {
+      throw new ERR_INVALID_ARG_TYPE(name, 'number', value);
+    }
     if (!isInt32(value)) {
-      if (typeof value !== 'number') {
-        throw new ERR_INVALID_ARG_TYPE(name, 'number', value);
-      }
       if (!NumberIsInteger(value)) {
         throw new ERR_OUT_OF_RANGE(name, 'an integer', value);
       }
@@ -98,10 +98,10 @@ const validateInt32 = hideStackFrames(
 );
 
 const validateUint32 = hideStackFrames((value, name, positive) => {
+  if (typeof value !== 'number') {
+    throw new ERR_INVALID_ARG_TYPE(name, 'number', value);
+  }
   if (!isUint32(value)) {
-    if (typeof value !== 'number') {
-      throw new ERR_INVALID_ARG_TYPE(name, 'number', value);
-    }
     if (!NumberIsInteger(value)) {
       throw new ERR_OUT_OF_RANGE(name, 'an integer', value);
     }

test/parallel/test-validators.js

@@ -10,6 +10,8 @@ const {
   validateNumber,
   validateObject,
   validateString,
+  validateInt32,
+  validateUint32,
 } = require('internal/validators');
 const { MAX_SAFE_INTEGER, MIN_SAFE_INTEGER } = Number;
 const outOfRangeError = {
@@ -41,6 +43,28 @@ const invalidArgValueError = {
   // validateInteger() works with unsafe integers.
   validateInteger(MAX_SAFE_INTEGER + 1, 'foo', 0, MAX_SAFE_INTEGER + 1);
   validateInteger(MIN_SAFE_INTEGER - 1, 'foo', MIN_SAFE_INTEGER - 1);
+
+  // validateInt32() and validateUint32()
+  [
+    Symbol(), 1n, {}, [], false, true, undefined, null,
+  ].forEach((val) => assert.throws(() => validateInt32(val, 'name'), {
+    code: 'ERR_INVALID_ARG_TYPE'
+  }));
+  [
+    2147483647 + 1, -2147483648 - 1, NaN,
+  ].forEach((val) => assert.throws(() => validateInt32(val, 'name'), {
+    code: 'ERR_OUT_OF_RANGE'
+  }));
+  [
+    Symbol(), 1n, {}, [], false, true, undefined, null,
+  ].forEach((val) => assert.throws(() => validateUint32(val, 'name'), {
+    code: 'ERR_INVALID_ARG_TYPE'
+  }));
+  [
+    4294967296, -1, NaN,
+  ].forEach((val) => assert.throws(() => validateUint32(val, 'name'), {
+    code: 'ERR_OUT_OF_RANGE'
+  }));
 }
 
 {