feat(rules): Added StringInstance rule

Author: ricardogobbosouza

README.md

@@ -133,6 +133,7 @@ The library can be loaded either as a standalone script, or through an [AMD](htt
 - [Scalar](docs/scalar.md)
 - [Slug](docs/slug.md)
 - [Sorted](docs/sorted.md)
+- [StringInstance](docs/string-instance.md)
 - [StringType](docs/string-type.md)
 - [StringVal](docs/string-val.md)
 - [SymbolicLink](docs/symbolic-link.md)

awesome-validator.min.js

@@ -0,0 +1,33 @@
+# String Instance
+
+Validates if the given input is string instance.
+
+Valid values:
+
+```js
+validator.stringInstance().validate('');
+validator.stringInstance().validate(' ');
+validator.stringInstance().validate('   ');
+validator.stringInstance().validate('0');
+validator.stringInstance().validate('foo');
+validator.stringInstance().validate(String());
+```
+
+Invalid values:
+
+```js
+validator.stringInstance().validate(undefined);
+validator.stringInstance().validate(null);
+validator.stringInstance().validate(true);
+validator.stringInstance().validate(false);
+validator.stringInstance().validate(0);
+validator.stringInstance().validate(1);
+validator.stringInstance().validate(-1);
+validator.stringInstance().validate(1.1);
+validator.stringInstance().validate(-1.1);
+validator.stringInstance().validate([]);
+validator.stringInstance().validate({});
+validator.stringInstance().validate(new Array());
+validator.stringInstance().validate(new Object());
+validator.stringInstance().validate(Object.create(null));
+```

docs/string-instance.md

@@ -54,6 +54,7 @@ export * from './roman';
 export * from './scalar';
 export * from './slug';
 export * from './sorted';
+export * from './string-instance';
 export * from './string-type';
 export * from './string-val';
 export * from './symbolic-link';

src/rules/index.ts

@@ -0,0 +1,11 @@
+import { AbstractConstructotName } from './abstract-constructor-name';
+
+export class StringInstance extends AbstractConstructotName {
+
+    /**
+     * Get constructor name.
+     */
+    protected getConstructorName(): string {
+        return 'String';
+    }
+}

src/rules/string-instance.ts

@@ -397,6 +397,13 @@ export class Validator extends rules.AllOf {
         return this.addRule(new rules.Sorted(fn, ascending));
     }
 
+    /**
+     * String Instance.
+     */
+    public stringInstance(): this {
+        return this.addRule(new rules.StringInstance());
+    }
+
     /**
      * String Type.
      */

src/validator.ts

@@ -0,0 +1,56 @@
+import { assert } from 'chai';
+
+import { AbstractRule } from '../../src/rules/abstract-rule';
+import { StringInstance } from '../../src/rules/string-instance';
+
+describe('String Instance', () => {
+
+    let stringInstance: StringInstance;
+
+    beforeEach(() => {
+        stringInstance = new StringInstance();
+    });
+
+    it('is rule', () => {
+        assert.instanceOf(stringInstance, AbstractRule);
+    });
+
+    it('values is valid', () => {
+        assert.isTrue(stringInstance.validate(String()));
+        assert.isTrue(stringInstance.validate(String('')));
+        assert.isTrue(stringInstance.validate(String('   ')));
+        assert.isTrue(stringInstance.validate(String('foo')));
+        assert.isTrue(stringInstance.validate(''));
+        assert.isTrue(stringInstance.validate('   '));
+        assert.isTrue(stringInstance.validate('foo'));
+    });
+
+    it('values is not valid', () => {
+        assert.isFalse(stringInstance.validate(Boolean()));
+        assert.isFalse(stringInstance.validate(Number()));
+        assert.isFalse(stringInstance.validate(null));
+        assert.isFalse(stringInstance.validate(undefined));
+        assert.isFalse(stringInstance.validate(true));
+        assert.isFalse(stringInstance.validate(false));
+        assert.isFalse(stringInstance.validate(0));
+        assert.isFalse(stringInstance.validate(-0));
+        assert.isFalse(stringInstance.validate(1));
+        assert.isFalse(stringInstance.validate(-1));
+        assert.isFalse(stringInstance.validate(0.0));
+        assert.isFalse(stringInstance.validate(-0.0));
+        assert.isFalse(stringInstance.validate(1.0));
+        assert.isFalse(stringInstance.validate(-1.0));
+        assert.isFalse(stringInstance.validate(0.1));
+        assert.isFalse(stringInstance.validate(-0.1));
+        assert.isFalse(stringInstance.validate(1.1));
+        assert.isFalse(stringInstance.validate(-1.1));
+        assert.isFalse(stringInstance.validate([]));
+        assert.isFalse(stringInstance.validate({}));
+        assert.isFalse(stringInstance.validate(new Array('foo')));
+        assert.isFalse(stringInstance.validate(new Object({foo: 'bar'})));
+
+        class Foo {}
+        assert.isFalse(stringInstance.validate(new Foo()));
+    });
+
+});

test/rules/string-instance.ts

@@ -71,6 +71,7 @@ describe('Validator', () => {
         assert.instanceOf(validator.slug(), Validator);
         assert.instanceOf(validator.sorted(), Validator);
         assert.instanceOf(validator.sorted(null, false), Validator);
+        assert.instanceOf(validator.stringInstance(), Validator);
         assert.instanceOf(validator.stringType(), Validator);
         assert.instanceOf(validator.stringVal(), Validator);
         assert.instanceOf(validator.symbolicLink(), Validator);