Use const by default (instead of let)

lib/fields/array.js

@@ -6,7 +6,7 @@ const Field = require('./field');
  * An array field. It uses provided field for data validation and serialization.
  *
  * @example
- *      let field = new ArrayField(new IntegerField());
+ *      const field = new ArrayField(new IntegerField());
  *
  *      field.deserialize([ 1, '2', '3.0' ]);        // returns [ 1, 2, 3 ]
  *      field.deserialize([ 'foo', 'bar' ]);         // throws validation error
@@ -50,8 +50,8 @@ class ArrayField extends Field {
             throw new Field.ValidationError(`Value must have at most ${this.params.maxLength} elements`);
         }
 
-        let result = [];
-        let errors = {};
+        const result = [];
+        const errors = {};
         let errorOccurred = false;
 
         for (let i = 0; i < value.length; ++i) {

lib/fields/boolean.js

@@ -6,7 +6,7 @@ const Field = require('./field');
  * A true/false field. Handles booleans and strings representing booleans. Serializes to boolean.
  *
  * @example
- *      let field = new BooleanField();
+ *      const field = new BooleanField();
  *
  *      field.deserialize(false); // returns false
  *      field.deserialize('yes'); // returns true

lib/fields/email.js

@@ -8,7 +8,7 @@ const StringField = require('./string');
  * A {@link StringField} which checks if value is a valid email.
  *
  * @example
- *      let field = new EmailField();
+ *      const field = new EmailField();
  *
  *      field.deserialize('SOME.EMAIL@GMAIL.COM'); // returns "some.email@gmail.com"
  *      field.deserialize('SOME.EMAIL.GMAIL.COM'); // throws validation error

lib/fields/enum.js

@@ -6,7 +6,7 @@ const Field = require('./field');
  * An enum field. It accepts only specified strings.
  *
  * @example
- *      let field = new EnumField([ 'one', 'two', 'three' ]);
+ *      const field = new EnumField([ 'one', 'two', 'three' ]);
  *
  *      field.deserialize('one'); // returns "one"
  *      field.deserialize('TWO'); // returns "two"
@@ -39,9 +39,9 @@ class EnumField extends Field {
             throw new Error('All choices must be a strings');
         }
 
-        let choicesMap = {};
+        const choicesMap = {};
 
-        for (let choice of choices) {
+        for (const choice of choices) {
             if (this.params.caseSensitive) {
                 choicesMap[choice.trim()] = choice;
             } else {

lib/fields/integer.js

@@ -7,7 +7,7 @@ const NumberField = require('./number');
  * A NumberField which additionally checks if value is an integer.
  *
  * @example
- *      let field = new IntegerField();
+ *      const field = new IntegerField();
  *
  *      field.deserialize(123); // returns 123
  *      field.deserialize(1.3); // throws validation error

lib/fields/model.js

@@ -7,7 +7,7 @@ const Field = require('./field');
  * An object field. It uses provided model for data validation and serialization.
  *
  * @example
- *      let field = new ModelField({
+ *      const field = new ModelField({
  *          id:   new IntegerField(),
  *          name: new StringField({ default: 'abc' })
  *      });

lib/fields/number.js

@@ -6,7 +6,7 @@ const Field = require('./field');
  * A number field. Accepts double precision real numbers.
  *
  * @example
- *      let field = new StringField({ maxLength: 3 });
+ *      const field = new StringField({ maxLength: 3 });
  *
  *      field.deserialize('123.4');  // returns 123.4
  *      field.deserialize(123.4);    // returns 123.4

lib/fields/object.js

@@ -6,7 +6,7 @@ const Field = require('./field');
  * An object field. It uses provided field for properties validation and serialization.
  *
  * @example
- *      let field = new ObjectField(new IntegerField());
+ *      const field = new ObjectField(new IntegerField());
  *
  *      field.deserialize({ foo: 1, bar: '2.0' });      // returns { foo: 1, bar: 2 }
  *      field.deserialize({ foo: 'bar' });              // throws validation error
@@ -40,11 +40,11 @@ class ObjectField extends Field {
             throw new Field.ValidationError('Value must be an object');
         }
 
-        let result = {};
-        let errors = {};
+        const result = {};
+        const errors = {};
         let errorOccurred = false;
 
-        for (let key of Object.keys(value)) {
+        for (const key of Object.keys(value)) {
             try {
                 result[key] = this.field.deserialize(value[key], options);
             } catch (error) {
@@ -68,9 +68,9 @@ class ObjectField extends Field {
      * @returns {object}
      */
     serialize(value, options) {
-        let result = {};
+        const result = {};
 
-        for (let key of Object.keys(value)) {
+        for (const key of Object.keys(value)) {
             result[key] = this.field.serialize(value[key], options);
         }
 

lib/fields/string.js

@@ -6,7 +6,7 @@ const Field = require('./field');
  * A text field. Accepts any string.
  *
  * @example
- *      let field = new StringField({ maxLength: 3 });
+ *      const field = new StringField({ maxLength: 3 });
  *
  *      field.deserialize('123');  // returns "123"
  *      field.deserialize(123);    // throws validation error

lib/model.js

@@ -89,13 +89,13 @@ class Model {
     static deserialize(data, options) {
         options = options || {};
 
-        let result = {};
-        let errors = {};
+        const result = {};
+        const errors = {};
 
         // Deserialize values
-        for (let key of Object.keys(this.fields)) {
-            let field = this.fields[key];
-            let value = data[key];
+        for (const key of Object.keys(this.fields)) {
+            const field = this.fields[key];
+            const value = data[key];
 
             try {
                 if (field.isBlank(value)) {
@@ -132,11 +132,11 @@ class Model {
     static serialize(data, options) {
         options = options || {};
 
-        let result = {};
+        const result = {};
 
-        for (let key of Object.keys(this.fields)) {
-            let field = this.fields[key];
-            let value = data[key];
+        for (const key of Object.keys(this.fields)) {
+            const field = this.fields[key];
+            const value = data[key];
 
             if (field.isBlank(value)) {
                 if (!options.partial) {
@@ -158,13 +158,13 @@ class Model {
      */
     static extend(fields) {
         // Create new class
-        let Cls = class extends this {};
+        const Cls = class extends this {};
 
         // Create fields property
         Cls.fields = Object.assign({}, this.fields);
 
         // Copy fields to fields property
-        for (let key of Object.keys(fields)) {
+        for (const key of Object.keys(fields)) {
             if (fields[key] instanceof Field) {
                 Cls.fields[key] = fields[key];
             } else {

test/fields/array-spec.js

@@ -11,16 +11,16 @@ chai.use(spies);
 describe('ArrayField', function() {
     describe('constructor', function() {
         it('should create new instance of field using specified field', function() {
-            let field = new Field();
-            let arrayField = new ArrayField(field);
+            const field = new Field();
+            const arrayField = new ArrayField(field);
 
             expect(arrayField).to.be.instanceOf(Field);
             expect(arrayField).to.be.instanceOf(ArrayField);
             expect(arrayField).to.have.property('field', field);
         });
 
         it('should create new instance of field when all params are specified', function () {
-            let field = new ArrayField(new Field(), {
+            const field = new ArrayField(new Field(), {
                 blank: true,
                 default: [ 1, 2 ],
                 minLength: 1,
@@ -32,7 +32,7 @@ describe('ArrayField', function() {
         });
 
         it('should throw error when field is not specified', function() {
-            let call = () => new ArrayField();
+            const call = () => new ArrayField();
 
             expect(call).to.throw('Field is missing');
         });
@@ -44,25 +44,25 @@ describe('ArrayField', function() {
                 deserialize() { return true }
             }
 
-            let field = new ArrayField(new CustomField());
+            const field = new ArrayField(new CustomField());
 
-            let result = field.deserialize([ 1, 2 ]);
+            const result = field.deserialize([ 1, 2 ]);
 
             expect(result).to.be.deep.equal([ true, true ]);
         });
 
         it('should deserialize empty array', function () {
-            let field = new ArrayField(new Field());
+            const field = new ArrayField(new Field());
 
-            let result = field.deserialize([]);
+            const result = field.deserialize([]);
 
             expect(result).to.be.deep.equal([]);
         });
 
         it('should throw error when value is not an array', function() {
-            let field = new ArrayField(new Field());
+            const field = new ArrayField(new Field());
 
-            let call = () => field.deserialize(123);
+            const call = () => field.deserialize(123);
 
             expect(call).to.throw(Field.ValidationError, 'Value must be an array');
         });
@@ -72,7 +72,7 @@ describe('ArrayField', function() {
                 deserialize(v) { throw new Field.ValidationError(v) }
             }
 
-            let field = new ArrayField(new InvalidField());
+            const field = new ArrayField(new InvalidField());
 
             try {
                 field.deserialize([ 1, 2 ]);
@@ -84,62 +84,62 @@ describe('ArrayField', function() {
         });
 
         it('should not intercept errors other than ValidationError', function () {
-            let error = new Error();
+            const error = new Error();
 
             class InvalidField extends Field {
                 deserialize(v) { throw error }
             }
 
-            let field = new ArrayField(new InvalidField());
+            const field = new ArrayField(new InvalidField());
 
-            let call = () => field.deserialize([ 1 ]);
+            const call = () => field.deserialize([ 1 ]);
 
             expect(call).to.throw(error);
         });
 
         it('should throw error array\'s length is less than min length', function() {
-            let field = new ArrayField(new Field(), { minLength: 2 });
+            const field = new ArrayField(new Field(), { minLength: 2 });
 
-            let call = () => field.deserialize([ 1 ]);
+            const call = () => field.deserialize([ 1 ]);
 
             expect(call).to.throw(Field.ValidationError, 'Value must have at least 2 elements');
         });
 
         it('should throw when array\'s length is greater than than max length', function() {
-            let field = new ArrayField(new Field(), { maxLength: 2 });
+            const field = new ArrayField(new Field(), { maxLength: 2 });
 
-            let call = () => field.deserialize([ 1, 2, 3 ]);
+            const call = () => field.deserialize([ 1, 2, 3 ]);
 
             expect(call).to.throw(Field.ValidationError, 'Value must have at most 2 elements');
         });
 
         it('should not throw when array\'s length is less than or equal to max length', function() {
-            let field = new ArrayField(new Field(), { maxLength: 2 });
+            const field = new ArrayField(new Field(), { maxLength: 2 });
 
-            let call1 = () => field.deserialize([ 1, 2 ]);
-            let call2 = () => field.deserialize([ 1 ]);
+            const call1 = () => field.deserialize([ 1, 2 ]);
+            const call2 = () => field.deserialize([ 1 ]);
 
             expect(call1).to.not.throw();
             expect(call2).to.not.throw();
         });
 
         it('should not throw when array\'s length is greater than or equal to min length', function() {
-            let field = new ArrayField(new Field(), { minLength: 2 });
+            const field = new ArrayField(new Field(), { minLength: 2 });
 
-            let call1 = () => field.deserialize([ 1, 2, 3 ]);
-            let call2 = () => field.deserialize([ 1, 2 ]);
+            const call1 = () => field.deserialize([ 1, 2, 3 ]);
+            const call2 = () => field.deserialize([ 1, 2 ]);
 
             expect(call1).to.not.throw();
             expect(call2).to.not.throw();
         });
 
         it('should pass specified options to child-field\'s deserialize method', function () {
-            let childField = new Field();
-            let arrayField = new ArrayField(childField);
+            const childField = new Field();
+            const arrayField = new ArrayField(childField);
 
             childField.deserialize = chai.spy();
 
-            let opts = { option: 'option' };
+            const opts = { option: 'option' };
 
             arrayField.deserialize([ 1 ], opts);
 
@@ -153,28 +153,28 @@ describe('ArrayField', function() {
                 serialize() { return true }
             }
 
-            let field = new ArrayField(new CustomField());
+            const field = new ArrayField(new CustomField());
 
-            let result = field.serialize([ 1, 2 ]);
+            const result = field.serialize([ 1, 2 ]);
 
             expect(result).to.be.deep.equal([ true, true ]);
         });
 
         it('should deserialize empty array', function () {
-            let field = new ArrayField(new Field());
+            const field = new ArrayField(new Field());
 
-            let result = field.serialize([]);
+            const result = field.serialize([]);
 
             expect(result).to.be.deep.equal([]);
         });
 
         it('should pass specified options to child-field\'s serialize method', function () {
-            let childField = new Field();
-            let arrayField = new ArrayField(childField);
+            const childField = new Field();
+            const arrayField = new ArrayField(childField);
 
             childField.serialize = chai.spy();
 
-            let opts = { option: 'option' };
+            const opts = { option: 'option' };
 
             arrayField.serialize([ 1 ], opts);