Add more string validators (#15)

package.json

@@ -45,7 +45,8 @@
 		"object"
 	],
 	"dependencies": {
-		"@sindresorhus/is": "^0.4.0"
+		"@sindresorhus/is": "^0.4.0",
+		"vali-date": "^1.0.0"
 	},
 	"devDependencies": {
 		"@types/node": "^8.0.31",

source/lib/predicates/string.ts

@@ -1,3 +1,4 @@
+import * as valiDate from 'vali-date';
 import { Predicate, Context } from './predicate';
 
 export class StringPredicate extends Predicate<string> {
@@ -6,6 +7,18 @@ export class StringPredicate extends Predicate<string> {
 		super('string', context);
 	}
 
+	/**
+	 * Test a string to have a specific length.
+	 *
+	 * @param length The length of the string.
+	 */
+	length(length: number) {
+		return this.addValidator({
+			message: value => `Expected string to have length \`${length}\`, got \`${value}\``,
+			validator: value => value.length === length
+		});
+	}
+
 	/**
 	 * Test a string to have a minimum length.
 	 *
@@ -13,18 +26,130 @@ export class StringPredicate extends Predicate<string> {
 	 */
 	minLength(length: number) {
 		return this.addValidator({
-			message: () => `Expected string length to be minimum ${length}`,
+			message: value => `Expected string to have a minimum length of \`${length}\`, got \`${value}\``,
 			validator: value => value.length >= length
 		});
 	}
 
+	/**
+	 * Test a string to have a maximum length.
+	 *
+	 * @param length The maximum length of the string.
+	 */
+	maxLength(length: number) {
+		return this.addValidator({
+			message: value => `Expected string to have a maximum length of \`${length}\`, got \`${value}\``,
+			validator: value => value.length <= length
+		});
+	}
+
+	/**
+	 * Test a string against a regular expression.
+	 *
+	 * @param regeExp The regular expression to match the value with.
+	 */
+	matches(regExp: RegExp) {
+		return this.addValidator({
+			message: value => `Expected string to match \`${regExp}\`, got \`${value}\``,
+			validator: value => regExp.test(value)
+		});
+	}
+
+	/**
+	 * Test a string to start with a specific value.
+	 *
+	 * @param searchString The value that should be the start of the string.
+	 */
+	startsWith(searchString: string) {
+		return this.addValidator({
+			message: value => `Expected string to start with \`${searchString}\`, got \`${value}\``,
+			validator: value => value.startsWith(searchString)
+		});
+	}
+
+	/**
+	 * Test a string to end with a specific value.
+	 *
+	 * @param searchString The value that should be the end of the string.
+	 */
+	endsWith(searchString: string) {
+		return this.addValidator({
+			message: value => `Expected string to end with \`${searchString}\`, got \`${value}\``,
+			validator: value => value.endsWith(searchString)
+		});
+	}
+
+	/**
+	 * Test a string to include a specific value.
+	 *
+	 * @param searchString The value that should be included in the string.
+	 */
+	includes(searchString: string) {
+		return this.addValidator({
+			message: value => `Expected string to include \`${searchString}\`, got \`${value}\``,
+			validator: value => value.includes(searchString)
+		});
+	}
+
+	/**
+	 * Test a string to be empty.
+	 */
+	get empty() {
+		return this.addValidator({
+			message: value => `Expected string to be empty, got \`${value}\``,
+			validator: value => value === ''
+		});
+	}
+
+	/**
+	 * Test a string to be not empty.
+	 */
+	get nonEmpty() {
+		return this.addValidator({
+			message: () => 'Expected string to not be empty',
+			validator: value => value !== ''
+		});
+	}
+
+	/**
+	 * Test a string to be equal to a specified string.
+	 *
+	 * @param expected Expected value to match.
+	 */
+	equals(expected: string) {
+		return this.addValidator({
+			message: value => `Expected string to be equal to \`${expected}\`, got \`${value}\``,
+			validator: value => value === expected
+		});
+	}
+
 	/**
 	 * Test a string to be alphanumeric.
 	 */
 	get alphanumeric() {
 		return this.addValidator({
-			message: value => `Expected string to contain only alphanumeric characters but received \`${value}\``,
+			message: value => `Expected string to be alphanumeric, got \`${value}\``,
 			validator: value => /^[a-z\d]+$/i.test(value)
 		});
 	}
+
+	/**
+	 * Test a string to be numeric.
+	 */
+	get numeric() {
+		return this.addValidator({
+			message: value => `Expected string to be numeric, got \`${value}\``,
+			validator: value => /^\d+$/i.test(value)
+		});
+	}
+
+	/**
+	 * Test a string to be a valid date.
+	 */
+	get date() {
+		return this.addValidator({
+			message: value => `Expected string to be a date, got \`${value}\``,
+			validator: value => valiDate(value)
+		});
+	}
 }

source/test/string.ts

@@ -6,13 +6,77 @@ test('string', t => {
 	t.throws(() => m(12, m.string), 'Expected argument to be of type `string` but received type `number`');
 });
 
+test('string.length', t => {
+	t.notThrows(() => m('foo', m.string.length(3)));
+	t.notThrows(() => m('foobar', m.string.length(6)));
+	t.throws(() => m('foo', m.string.length(4)), 'Expected string to have length `4`, got `foo`');
+});
+
 test('string.minLength', t => {
 	t.notThrows(() => m('foo', m.string.minLength(2)));
 	t.notThrows(() => m('foo', m.string.minLength(3)));
-	t.throws(() => m('foo', m.string.minLength(4)), 'Expected string length to be minimum 4');
+	t.throws(() => m('foo', m.string.minLength(4)), 'Expected string to have a minimum length of `4`, got `foo`');
+});
+
+test('string.maxLength', t => {
+	t.notThrows(() => m('foo', m.string.maxLength(3)));
+	t.notThrows(() => m('foo', m.string.maxLength(5)));
+	t.throws(() => m('foo', m.string.maxLength(2)), 'Expected string to have a maximum length of `2`, got `foo`');
+});
+
+test('string.matches', t => {
+	t.notThrows(() => m('foo', m.string.matches(/^f.o$/)));
+	t.notThrows(() => m('Foo', m.string.matches(/^f.o$/i)));
+	t.throws(() => m('Foo', m.string.matches(/^f.o$/)), 'Expected string to match `/^f.o$/`, got `Foo`');
+	t.throws(() => m('bar', m.string.matches(/^f.o$/i)), 'Expected string to match `/^f.o$/i`, got `bar`');
+});
+
+test('string.startsWith', t => {
+	t.notThrows(() => m('foo', m.string.startsWith('fo')));
+	t.notThrows(() => m('foo', m.string.startsWith('f')));
+	t.throws(() => m('foo', m.string.startsWith('oo')), 'Expected string to start with `oo`, got `foo`');
+	t.throws(() => m('foo', m.string.startsWith('b')), 'Expected string to start with `b`, got `foo`');
+});
+
+test('string.endsWith', t => {
+	t.notThrows(() => m('foo', m.string.endsWith('oo')));
+	t.notThrows(() => m('foo', m.string.endsWith('o')));
+	t.throws(() => m('foo', m.string.endsWith('fo')), 'Expected string to end with `fo`, got `foo`');
+	t.throws(() => m('foo', m.string.endsWith('ar')), 'Expected string to end with `ar`, got `foo`');
+});
+
+test('string.includes', t => {
+	t.notThrows(() => m('foo', m.string.includes('fo')));
+	t.throws(() => m('foo', m.string.includes('bar')), 'Expected string to include `bar`, got `foo`');
+});
+
+test('string.empty', t => {
+	t.notThrows(() => m('', m.string.empty));
+	t.throws(() => m('foo', m.string.empty), 'Expected string to be empty, got `foo`');
+});
+
+test('string.nonEmpty', t => {
+	t.notThrows(() => m('foo', m.string.nonEmpty));
+	t.throws(() => m('', m.string.nonEmpty), 'Expected string to not be empty');
+});
+
+test('string.equals', t => {
+	t.notThrows(() => m('foo', m.string.equals('foo')));
+	t.throws(() => m('bar', m.string.equals('foo')), 'Expected string to be equal to `foo`, got `bar`');
 });
 
 test('string.alphanumeric', t => {
 	t.notThrows(() => m('Foo123', m.string.alphanumeric));
-	t.throws(() => m('Foo123!', m.string.alphanumeric), 'Expected string to contain only alphanumeric characters but received `Foo123!`');
+	t.throws(() => m('Foo123!', m.string.alphanumeric), 'Expected string to be alphanumeric, got `Foo123!`');
+});
+
+test('string.numeric', t => {
+	t.notThrows(() => m('123', m.string.numeric));
+	t.throws(() => m('Foo123', m.string.numeric), 'Expected string to be numeric, got `Foo123`');
+});
+
+test('string.date', t => {
+	t.notThrows(() => m('2017-03-02', m.string.date));
+	t.notThrows(() => m('2017-03-02T10:00:00Z', m.string.date));
+	t.throws(() => m('foo', m.string.date), 'Expected string to be a date, got `foo`');
 });