tls: use validateNumber for options.minDHSize

If user sets invalid type for options.minDHSize in
tls.connect(), it's not internal issue of Node.js. So
validateNumber() is more proper than assert(). Plus,
set min of validateNumber() as 1 to check minDHSize
is positive.

Refs: nodejs#49896

lib/_tls_wrap.js

@@ -1739,11 +1739,7 @@ exports.connect = function connect(...args) {
     options.singleUse = true;
 
   assert(typeof options.checkServerIdentity === 'function');
-  assert(typeof options.minDHSize === 'number',
-         'options.minDHSize is not a number: ' + options.minDHSize);
-  assert(options.minDHSize > 0,
-         'options.minDHSize is not a positive number: ' +
-         options.minDHSize);
+  validateNumber(options.minDHSize, 'options.minDHSize', 1);
 
   const context = options.secureContext || tls.createSecureContext(options);
 

test/parallel/test-tls-client-mindhsize.js

@@ -74,16 +74,23 @@ testDHE1024();
 assert.throws(() => test(512, true, common.mustNotCall()),
               /DH parameter is less than 1024 bits/);
 
-let errMessage = /minDHSize is not a positive number/;
-[0, -1, -Infinity, NaN].forEach((minDHSize) => {
-  assert.throws(() => tls.connect({ minDHSize }),
-                errMessage);
-});
+for (const minDHSize of [0, -1, -Infinity, NaN]) {
+  assert.throws(() => {
+    tls.connect({ minDHSize });
+  }, {
+    code: 'ERR_OUT_OF_RANGE',
+    name: 'RangeError',
+  })
+}
 
-errMessage = /minDHSize is not a number/;
-[true, false, null, undefined, {}, [], '', '1'].forEach((minDHSize) => {
-  assert.throws(() => tls.connect({ minDHSize }), errMessage);
-});
+for (const minDHSize of [true, false, null, undefined, {}, [], '', '1']) {
+  assert.throws(() => {
+    tls.connect({ minDHSize });
+  }, {
+    code: 'ERR_INVALID_ARG_TYPE',
+    name: 'TypeError',
+  })
+}
 
 process.on('exit', function() {
   assert.strictEqual(nsuccess, 1);