lib: introduce internal/validators

Create a file to centralize argument validators that are used in
multiple internal modules.
Move validateInt32 and validateUint32 to this file.

PR-URL: https://github.com/nodejs/node/pull/19973
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: James M Snell <jasnell@gmail.com>

1 files changed, 58 insertions, 0 deletions

diff --git a/lib/internal/validators.js b/lib/internal/validators.js
new file mode 100644
index 0000000000..556bfb2dc0
--- /dev/null
+++ b/lib/internal/validators.js
@@ -0,0 +1,58 @@
+'use strict';
+
+const {
+  ERR_INVALID_ARG_TYPE,
+  ERR_OUT_OF_RANGE
+} = require('internal/errors').codes;
+
+function isInt32(value) {
+  return value === (value | 0);
+}
+
+function isUint32(value) {
+  return value === (value >>> 0);
+}
+
+function validateInt32(value, name) {
+  if (!isInt32(value)) {
+    let err;
+    if (typeof value !== 'number') {
+      err = new ERR_INVALID_ARG_TYPE(name, 'number', value);
+    } else if (!Number.isInteger(value)) {
+      err = new ERR_OUT_OF_RANGE(name, 'an integer', value);
+    } else {
+      // 2 ** 31 === 2147483648
+      err = new ERR_OUT_OF_RANGE(name, '> -2147483649 && < 2147483648', value);
+    }
+    Error.captureStackTrace(err, validateInt32);
+    throw err;
+  }
+}
+
+function validateUint32(value, name, positive) {
+  if (!isUint32(value)) {
+    let err;
+    if (typeof value !== 'number') {
+      err = new ERR_INVALID_ARG_TYPE(name, 'number', value);
+    } else if (!Number.isInteger(value)) {
+      err = new ERR_OUT_OF_RANGE(name, 'an integer', value);
+    } else {
+      const min = positive ? 1 : 0;
+      // 2 ** 32 === 4294967296
+      err = new ERR_OUT_OF_RANGE(name, `>= ${min} && < 4294967296`, value);
+    }
+    Error.captureStackTrace(err, validateUint32);
+    throw err;
+  } else if (positive && value === 0) {
+    const err = new ERR_OUT_OF_RANGE(name, '>= 1 && < 4294967296', value);
+    Error.captureStackTrace(err, validateUint32);
+    throw err;
+  }
+}
+
+module.exports = {
+  isInt32,
+  isUint32,
+  validateInt32,
+  validateUint32
+};