feat: add support for label method

README.md

@@ -33,6 +33,7 @@ Schema for data modeling & validation
     - [`when(condition: (schemaSpec: SchemaDeclaration<DataType, ErrorMsgType>) => Type)`](#whencondition-schemaspec-schemadeclarationdatatype-errormsgtype--type)
     - [`check(value: ValueType, data?: DataType):CheckResult`](#checkvalue-valuetype-data-datatypecheckresult)
     - [`checkAsync(value: ValueType, data?: DataType):Promise<CheckResult>`](#checkasyncvalue-valuetype-data-datatypepromisecheckresult)
+    - [`label(label: string)`](#labellabel-string)
   - [StringType(errorMessage?: string)](#stringtypeerrormessage-string)
     - [`isEmail(errorMessage?: string)`](#isemailerrormessage-string)
     - [`isURL(errorMessage?: string)`](#isurlerrormessage-string)
@@ -515,6 +516,23 @@ type.checkAsync(1).then(checkResult => {
 });
 ```
 
+#### `label(label: string)`
+
+Overrides the key name in error messages.
+
+```js
+MixedType().label('Username');
+```
+
+Eg:
+
+```js
+SchemaModel({
+  first_name: StringType().label('First name'),
+  age: NumberType().label('Age')
+});
+```
+
 ### StringType(errorMessage?: string)
 
 Define a string type. Supports all the same methods as [MixedType](#mixedtype).

src/MixedType.ts

@@ -24,6 +24,7 @@ export class MixedType<ValueType = any, DataType = any, E = ErrorMessageType, L
   protected emptyAllowed = false;
   protected rules: RuleType<ValueType, DataType, E | string>[] = [];
   protected priorityRules: RuleType<ValueType, DataType, E | string>[] = [];
+  protected fieldLabel?: string;
 
   schemaSpec: SchemaDeclaration<DataType, E>;
   value: any;
@@ -43,7 +44,9 @@ export class MixedType<ValueType = any, DataType = any, E = ErrorMessageType, L
     if (this.required && !checkRequired(value, this.trim, this.emptyAllowed)) {
       return {
         hasError: true,
-        errorMessage: formatErrorMessage(this.requiredMessage, { name: fieldName })
+        errorMessage: formatErrorMessage(this.requiredMessage, {
+          name: this.fieldLabel || fieldName
+        })
       };
     }
 
@@ -70,7 +73,9 @@ export class MixedType<ValueType = any, DataType = any, E = ErrorMessageType, L
     if (this.required && !checkRequired(value, this.trim, this.emptyAllowed)) {
       return Promise.resolve({
         hasError: true,
-        errorMessage: formatErrorMessage(this.requiredMessage, { name: fieldName })
+        errorMessage: formatErrorMessage(this.requiredMessage, {
+          name: this.fieldLabel || fieldName
+        })
       });
     }
 
@@ -160,6 +165,14 @@ export class MixedType<ValueType = any, DataType = any, E = ErrorMessageType, L
     );
     return this;
   }
+
+  /**
+   * Overrides the key name in error messages.
+   */
+  label(label: string) {
+    this.fieldLabel = label;
+    return this;
+  }
 }
 
 export default function getMixedType<DataType = any, E = ErrorMessageType>() {

test/MixedTypeSpec.js

@@ -1,6 +1,6 @@
-/* eslint-disable @typescript-eslint/no-var-requires */
-const chai = require('chai');
-const schema = require('../src');
+import chai, { expect } from 'chai';
+import * as schema from '../src';
+
 chai.should();
 const { StringType, SchemaModel, NumberType, ArrayType, MixedType } = schema;
 
@@ -460,4 +460,16 @@ describe('#MixedType', () => {
       }
     }, 100);
   });
+
+  it('Should use label to override the field name in the error message', () => {
+    const schema = SchemaModel({
+      first_name: StringType().label('First Name').isRequired(),
+      age: NumberType().label('Age').isRequired()
+    });
+
+    expect(schema.check({})).to.deep.equal({
+      first_name: { hasError: true, errorMessage: 'First Name is a required field' },
+      age: { hasError: true, errorMessage: 'Age is a required field' }
+    });
+  });
 });