convert property in array type

README.md

@@ -486,6 +486,19 @@ check({ roles: ["user", "admin", "user"] }); // Fail
 check({ roles: [1, 2, 1] }); // Fail
 ```
 
+**Example for `convert`:**
+
+```js
+const schema = {
+    roles: { type: "array", items: 'string', convert: true }
+}
+const check = v.compile(schema);
+
+check({ roles: ["user"] }); // Valid
+check({ roles: "user" }); // Valid
+// After both validation: roles = ["user"]
+```
+
 ### Properties
 Property | Default  | Description
 -------- | -------- | -----------
@@ -497,6 +510,7 @@ Property | Default  | Description
 `unique` | `null` | The array must be unique (array of objects is always unique).
 `enum`	 | `null`   | Every element must be an element of the `enum` array.
 `items`	 | `null`   | Schema for array items.
+`convert`| `null`   | Wrap value into array if different type provided
 
 ## `boolean`
 This is a `Boolean` validator.

lib/rules/array.js

@@ -5,6 +5,16 @@
 module.exports = function ({ schema, messages }, path, context) {
 	const src = [];
 
+	let sanitized = false;
+	if (schema.convert === true) {
+		sanitized = true;
+		src.push(`
+			if (!Array.isArray(value)) {
+				value = [value];
+			}
+		`);
+	}
+
 	src.push(`
 		if (!Array.isArray(value)) {
 			${this.makeError({ type: "array", actual: "value", messages })}
@@ -99,6 +109,7 @@ module.exports = function ({ schema, messages }, path, context) {
 	}
 
 	return {
+		sanitized,
 		source: src.join("\n")
 	};
 };

test/rules/array.spec.js

@@ -131,6 +131,11 @@ describe("Test rule: array", () => {
 		expect(customFnItems).toHaveBeenNthCalledWith(1, 1, [], schema.numbers.items, "numbers[]", { numbers: [1,2] }, expect.any(Object));
 		expect(customFnItems).toHaveBeenNthCalledWith(2, 2, [], schema.numbers.items, "numbers[]", { numbers: [1,2] }, expect.any(Object));
 	});
+
+	it("should wrap single value into array", () => {
+		const check	= v.compile({ $$root: true, type: "array", items: "string", convert: true });
+		expect(check("a")).toEqual(true);
+	});
 
 	describe("Test sanitization", () => {
 

test/typescript/rules/array.spec.ts

@@ -93,6 +93,11 @@ describe('TypeScript Definitions', () => {
 				{ type: 'string', field: '[3]', actual: true, message: 'The \'[3]\' field must be a string.' },
 			]);
 		});
+
+		it("should wrap single value into array", () => {
+			const check	= v.compile({ $$root: true, type: "array", items: "string", convert: true });
+			expect(check("a")).toEqual(true);
+		});
 	});
 
 	describe("Test sanitization", () => {