Fix issue XRPLF#2858: Add tests for improved error messages in field validation functions

Author: lacostenycoder

packages/xrpl/test/models/transactions/common.test.ts

@@ -0,0 +1,57 @@
+import { validateRequiredField, validateOptionalField } from '../../../src/models/transactions/common'
+import { ValidationError } from '../../../src/errors'
+
+describe('validateRequiredField', () => {
+  const txMock = {
+    TransactionType: 'Payment',
+    amount: 42,
+    account: 'rXYZ',
+  }
+
+  it('throws an error with expected and actual types', () => {
+    expect(() =>
+      validateRequiredField(txMock, 'amount', (val) => typeof val === 'string', 'string')
+    ).toThrow(new ValidationError('Payment: invalid field amount: expected string, received number'))
+  })
+
+  it('does not throw if value is valid', () => {
+    expect(() =>
+      validateRequiredField(txMock, 'account', (val) => typeof val === 'string', 'string')
+    ).not.toThrow()
+  })
+
+  it('throws without expectedType if not passed', () => {
+    expect(() =>
+      validateRequiredField(txMock, 'amount', (val) => typeof val === 'string')
+    ).toThrow(new ValidationError('Payment: invalid field amount'))
+  })
+
+  it('throws when field is missing', () => {
+    expect(() =>
+      validateRequiredField(txMock, 'nonExistentField', (val) => typeof val === 'string')
+    ).toThrow(new ValidationError('Payment: missing field nonExistentField'))
+  })
+})
+
+describe('validateOptionalField', () => {
+  const txMock = {
+    TransactionType: 'Payment',
+    memo: 123,
+  }
+
+  const txNoMemo = {
+    TransactionType: 'Payment',
+  }
+
+  it('skips validation if value is undefined', () => {
+    expect(() =>
+      validateOptionalField(txNoMemo, 'memo', (val) => typeof val === 'string', 'string')
+    ).not.toThrow()
+  })
+
+  it('delegates to validation if value is defined', () => {
+    expect(() =>
+      validateOptionalField(txMock, 'memo', (val) => typeof val === 'string', 'string')
+    ).toThrow(new ValidationError('Payment: invalid field memo: expected string, received number'))
+  })
+})