[feature] added rule for currency validation

Author: ishan-srivastava

README.md

@@ -70,32 +70,34 @@ $ npm run bench
     - [Properties](#properties-1)
   - [`class`](#class)
     - [Properties](#properties-2)
-  - [`date`](#date)
+  - [`currency`](#currency)
     - [Properties](#properties-3)
-  - [`email`](#email)
+  - [`date`](#date)
     - [Properties](#properties-4)
-  - [`enum`](#enum)
+  - [`email`](#email)
     - [Properties](#properties-5)
-  - [`equal`](#equal)
+  - [`enum`](#enum)
     - [Properties](#properties-6)
-  - [`forbidden`](#forbidden)
+  - [`equal`](#equal)
     - [Properties](#properties-7)
+  - [`forbidden`](#forbidden)
+    - [Properties](#properties-8)
   - [`function`](#function)
   - [`luhn`](#luhn)
   - [`mac`](#mac)
   - [`multi`](#multi)
   - [`number`](#number)
-    - [Properties](#properties-8)
-  - [`object`](#object)
     - [Properties](#properties-9)
-  - [`string`](#string)
+  - [`object`](#object)
     - [Properties](#properties-10)
-  - [`tuple`](#tuple)
+  - [`string`](#string)
     - [Properties](#properties-11)
-  - [`url`](#url)
+  - [`tuple`](#tuple)
     - [Properties](#properties-12)
-  - [`uuid`](#uuid)
+  - [`url`](#url)
     - [Properties](#properties-13)
+  - [`uuid`](#uuid)
+    - [Properties](#properties-14)
 - [Custom validator](#custom-validator)
   - [Custom validation for built-in rules](#custom-validation-for-built-in-rules)
 - [Custom error messages (l10n)](#custom-error-messages-l10n)
@@ -514,6 +516,30 @@ Property | Default  | Description
 -------- | -------- | -----------
 `instanceOf` | `null` | Checked Class.
 
+## `currency`
+This is a `Currency` validator to check if the value is a valid currency string.
+
+```js
+const schema = {
+    money_amount: { type: "currency", currencySymbol: '$' }
+}
+
+v.validate({ money_amount: '$12.99'}, schema); // Valid
+v.validate({ money_amount: '$0.99'}, schema); // Valid
+v.validate({ money_amount: '$12,345.99'}, schema); // Valid
+v.validate({ money_amount: '$123,456.99'}, schema); // Valid
+
+v.validate({ money_amount: '$1234,567.99'}, schema); // Fail
+v.validate({ money_amount: '$1,23,456.99'}, schema); // Fail
+v.validate({ money_amount: '$12,34.5.99' }, schema); // Fail
+```
+
+### Properties
+Property | Default  | Description
+-------- | -------- | -----------
+`currencySymbol` | `null` | The currency symbol expected in string (as prefix).
+`symbolOptional` | `false` | Toggle to make the symbol optional in string, although, if present it would only allow the currencySymbol.
+
 ## `date`
 This is a `Date` validator.
 

lib/messages.js

@@ -41,6 +41,8 @@ module.exports = {
 
 	boolean: "The '{field}' field must be a boolean.",
 
+	currency: "The '{field}' must be a valid currency format",
+
 	date: "The '{field}' field must be a Date.",
 	dateMin: "The '{field}' field must be greater than or equal to {expected}.",
 	dateMax: "The '{field}' field must be less than or equal to {expected}.",

lib/rules/currency.js

@@ -0,0 +1,22 @@
+"use strict";
+const CURRENCY_REGEX = `(?=.*\\\\d)^~1(([0-9]\\\\d{0,2}(,\\\\d{3})*)|0)?(\\\\.\\\\d{1,2})?$`;
+/**	Signature: function(value, field, parent, errors, context)
+ */
+
+module.exports = function ({schema, messages}, path, context) {
+	const currencySymbol = schema.currencySymbol || null;
+	let isCurrencySymbolMandatory = !schema.symbolOptional;
+	let finalRegex = CURRENCY_REGEX.replace('~1', currencySymbol ? (`\\\\${currencySymbol}${(isCurrencySymbolMandatory ? '' : '?')}`) : '');
+	return {
+		source: `
+			if (!value.match(new RegExp('${finalRegex}'))){
+			return ${this.makeError({
+			type: "currency",
+			actual: "value",
+			messages
+		})}
+			}
+			return value;
+		`
+	};
+};

lib/validator.js

@@ -14,6 +14,7 @@ function loadRules() {
 		boolean: require("./rules/boolean"),
 		class: require("./rules/class"),
 		custom: require("./rules/custom"),
+		currency: require("./rules/currency"),
 		date: require("./rules/date"),
 		email: require("./rules/email"),
 		enum: require("./rules/enum"),
@@ -384,12 +385,12 @@ class Validator {
 		const ruleVName = "rule" + ruleIndex;
 		const fnCustomErrorsVName = "fnCustomErrors" + ruleIndex;
 		if (typeof schema[fnName] == "function") {
-			if (context.customs[ruleIndex]) { 
+			if (context.customs[ruleIndex]) {
 				context.customs[ruleIndex].messages = messages;
 				context.customs[ruleIndex].schema = schema;
 			}
 			else context.customs[ruleIndex] = { messages, schema };
-                  
+
 			if (this.opts.useNewCustomCheckerFunction) {
 				return `
                const ${ruleVName} = context.customs[${ruleIndex}];

test/rules/currency.spec.js

@@ -0,0 +1,44 @@
+"use strict";
+
+const Validator = require("../../lib/validator");
+const v = new Validator();
+
+describe("Test rule: currency", () => {
+	it("should have decimal optional, and correctly placed if present", () => {
+		const check = v.compile({$$root: true, type: "currency", 'currencySymbol': '$', 'symbolOptional': true});
+		expect(check("$12.2")).toEqual(true);
+		expect(check("$12,222.2")).toEqual(true);
+		expect(check("$12,222")).toEqual(true);
+		expect(check("$12,222.0")).toEqual(true);
+		expect(check("$1.22.00")).toEqual([{"actual": "$1.22.00", "field": undefined, "message": "The '' must be a valid currency format", "type": "currency"}]);
+	});
+
+	it("should check comma placement is correct", () => {
+		const check = v.compile({$$root: true, type: "currency", 'currencySymbol': '$', 'symbolOptional': true});
+		expect(check("$12.2")).toEqual(true);
+		expect(check("$12,222.2")).toEqual(true);
+		expect(check("$122,222.2")).toEqual(true);
+		expect(check("$1234,222.2")).toEqual([{"actual": "$1234,222.2", "field": undefined, "message": "The '' must be a valid currency format", "type": "currency"}]);
+		expect(check("$1,2,222")).toEqual( [{"actual": "$1,2,222", "field": undefined, "message": "The '' must be a valid currency format", "type": "currency"}]);
+	});
+
+	it("should not allow any currency symbol , if not supplied in schema", () => {
+		let check = v.compile({$$root: true, type: "currency"});
+		expect(check("12.2")).toEqual(true);
+		expect(check("$12.2")).toEqual( [{"actual": "$12.2", "field": undefined, "message": "The '' must be a valid currency format", "type": "currency"}]);
+	});
+
+	it("should not allow any other currency symbol, other than supplied in schema", () => {
+		let check = v.compile({$$root: true, type: "currency", 'currencySymbol': '$', 'symbolOptional': false});
+		expect(check("$12.2")).toEqual(true);
+		expect(check("#12.2")).toEqual([{"actual": "#12.2", "field": undefined, "message": "The '' must be a valid currency format", "type": "currency"}]);
+	});
+
+	it("should keep currency symbol optional, if symbolOptional is true in schema", () => {
+		let check = v.compile({$$root: true, type: "currency", 'currencySymbol': '$', 'symbolOptional': true});
+		expect(check("$12.2")).toEqual(true);
+		expect(check("12.2")).toEqual(true);
+		expect(check("#12.2")).toEqual([{"actual": "#12.2", "field": undefined, "message": "The '' must be a valid currency format", "type": "currency"}]
+		);
+	});
+});

test/typescript/validator.spec.ts

@@ -14,7 +14,7 @@ describe('TypeScript Definitions', () => {
             expect(v.validate).toBeInstanceOf(Function);
             expect(v.add).toBeInstanceOf(Function);
 
-            expect(Object.keys(v.rules)).toHaveProperty('length', 20);
+            expect(Object.keys(v.rules)).toHaveProperty('length', 21);
         });
 
         it('should create instance with custom messages', () => {

test/validator.spec.js

@@ -12,7 +12,7 @@ describe("Test constructor", () => {
 		expect(v.validate).toBeInstanceOf(Function);
 		expect(v.add).toBeInstanceOf(Function);
 
-		expect(Object.keys(v.rules).length).toBe(20);
+		expect(Object.keys(v.rules).length).toBe(21);
 	});
 
 	it("should create instance with custom messages", () => {