Added validator module and tests

lib/validator.js

@@ -0,0 +1,88 @@
+'use strict';
+
+/**
+ * validEmail() Check that an email email matches a simple valid email regex
+ *
+ * @param {string} email - The email address to be validated
+ * @param {RegExp} [emailRegex] - RegExp to use for validation
+ *
+ * @return {boolean} - If the email address is valid
+ */
+function validEmail(email, emailRegex) {
+	if (typeof emailRegex === 'undefined')
+		emailRegex = /\S+@\S+\.\S+/;
+
+	return emailRegex.test(email);
+}
+
+/**
+ * passwordsMatch() Check that two password fields match
+ *
+ * @param {string} password1 - The first password
+ * @param {string} password2 - The second password
+ *
+ * @return {boolean} - If the passwords match
+ */
+function passwordsMatch(password1, password2) {
+	if (typeof password1 !== 'string' || typeof password2 !== 'string')
+		return false;
+
+	return password1 === password2;
+}
+
+/**
+ * validate() Main validation wrapper function to validate full POST form body
+ *
+ * @param {Object} body - The body of an express request
+ * @param {Array<string>} fields - Fields to check
+ * @param {Object} [validation] - Fields to run special validation against
+ *
+ * @return {Object} results
+ * @return {Map<string, string>} results.fields - Sanitised and validated fields
+ */
+function validate(body, fields, validation = {}) {
+	const fieldsMap = new Map();
+
+	// Check all required fields are not empty, and sanitise them
+	for (const field of fields) {
+		const cleanField = body[field]?.trim() ?? false;
+
+		if (cleanField === false || cleanField.length < 1)
+			throw new Error(`${field} is missing`);
+
+		fieldsMap.set(field, cleanField);
+	}
+
+	// Handle validation as required in options
+	for (const [ check, checkOpts ] of Object.entries(validation)) {
+		let valid;
+
+		// Handlers for validation types go here
+		switch (check) {
+			case 'email':
+				valid = validEmail(fieldsMap.get(checkOpts));
+				break;
+			case 'password':
+				valid = passwordsMatch(
+					fieldsMap.get(checkOpts[0]),
+					fieldsMap.get(checkOpts[1])
+				);
+				break;
+			default:
+				throw new Error('Invalid validation type');
+		}
+
+		if (!valid)
+			throw new Error(`Invalid ${check}`);
+	}
+
+	return {
+		fields: fieldsMap
+	};
+}
+
+module.exports = {
+	validEmail: validEmail,
+	passwordsMatch: passwordsMatch,
+	validate: validate
+};