add test

packages/web3-utils/test/unit/formatter.test.ts

@@ -479,6 +479,26 @@ describe('formatter', () => {
 					).toEqual(new Uint8Array([16, 11, 202]));
 				});
 			});
+
+			describe('string', () => {
+				it('should format string for 123', () => {
+					expect(
+						format({ format: 'string' }, 123, {
+							number: FMT_NUMBER.STR,
+							bytes: FMT_BYTES.HEX,
+						}),
+					).toBe('123');
+				});
+
+				it('should format string for 0x1234', () => {
+					expect(
+						format({ format: 'string' }, 0x1234, {
+							number: FMT_NUMBER.STR,
+							bytes: FMT_BYTES.UINT8ARRAY,
+						}),
+					).toBe('0x1234');
+				});
+			});
 		});
 
 		describe('array values', () => {
@@ -827,6 +847,32 @@ describe('formatter', () => {
 
 				expect(result).toEqual(expected);
 			});
+
+			it('should format object with oneOf', () => {
+				const schema = {
+					type: 'object',
+					properties: {
+						from: {
+							format: 'address',
+						},
+						to: {
+							oneOf: [{ format: 'string' }, { type: 'null' }],
+						},
+					},
+				};
+
+				const data ={
+					from: '0x7ed0e85b8e1e925600b4373e6d108f34ab38a401',
+					to: 123,
+				}
+				;
+
+				const result = { from: '0x7ed0e85b8e1e925600b4373e6d108f34ab38a401', to: '123' };
+
+				expect(
+					format(schema, data, { number: FMT_NUMBER.HEX, bytes: FMT_BYTES.HEX }),
+				).toEqual(result);
+			});
 		});
 		describe('isDataFormat', () => {
 			describe('valid cases', () => {