diff --git a/src/validateRegisterForm.test.js b/src/validateRegisterForm.test.js
index 6d86ab9..74b2d40 100644
--- a/src/validateRegisterForm.test.js
+++ b/src/validateRegisterForm.test.js
@@ -1,3 +1,4 @@
+/* eslint-disable max-len */
 'use strict';
 
 describe(`Function 'validateRegisterForm':`, () => {
@@ -8,8 +9,9 @@ describe(`Function 'validateRegisterForm':`, () => {
   });
 
   it(`should return object`, () => {
-    expect(typeof validateRegisterForm('test@mail.com', 'P@ssword1!'))
-      .toBe('object');
+    expect(typeof validateRegisterForm('test@mail.com', 'P@ssword1!')).toBe(
+      'object'
+    );
   });
 
   it(`should return success message for the valid input`, () => {
@@ -19,12 +21,76 @@ describe(`Function 'validateRegisterForm':`, () => {
     expect(isValid.message).toBe('Email and password are valid.');
   });
 
-  it(`should return error for valid email and password without number`, () => {
+  it(`should return error for valid email 
+    and password without number`, () => {
     const invalidPassword = validateRegisterForm('test@mail.com', 'P@ssword');
 
     expect(invalidPassword.code).toBe(422);
     expect(invalidPassword.message).toBe('Password is invalid.');
   });
 
-  // write more tests here
+  it(`should return error for valid email and password.length < 8`, () => {
+    const invalidPassword = validateRegisterForm('test@mail.com', 'P@ssw1');
+
+    expect(invalidPassword.code).toBe(422);
+    expect(invalidPassword.message).toBe('Password is invalid.');
+  });
+
+  it(`should return error for valid email and password.length > 16`, () => {
+    const invalidPassword = validateRegisterForm(
+      'test@mail.com',
+      'P@sswordPas2Word122'
+    );
+
+    expect(invalidPassword.code).toBe(422);
+    expect(invalidPassword.message).toBe('Password is invalid.');
+  });
+
+  it(`should return error for valid email 
+    and password without big letter`, () => {
+    const invalidPassword = validateRegisterForm('test@mail.com', 'p@ssword1');
+
+    expect(invalidPassword.code).toBe(422);
+    expect(invalidPassword.message).toBe('Password is invalid.');
+  });
+
+  it(`should return error for valid email 
+    and password without special character`, () => {
+    const invalidPassword = validateRegisterForm('test@mail.com', 'PPssword1');
+
+    expect(invalidPassword.code).toBe(422);
+    expect(invalidPassword.message).toBe('Password is invalid.');
+  });
+
+  it(`should return error for valid email and password with spaces`, () => {
+    const invalidPassword = validateRegisterForm('test@mail.com', 'P@ss word1');
+
+    expect(invalidPassword.code).toBe(422);
+    expect(invalidPassword.message).toBe('Password is invalid.');
+  });
+
+  it('should return error when email format is invalid', () => {
+    const invalidEmail = validateRegisterForm('testmail.com', 'P@ssword1!');
+
+    expect(invalidEmail.code).toBe(422);
+    expect(invalidEmail.message).toBe('Email is invalid.');
+  });
+
+  it('should return error when both email and password are invalid', () => {
+    const invalidEmailAndPassword = validateRegisterForm('test@com', 'ssword1');
+
+    expect(invalidEmailAndPassword.code).toEqual(500);
+
+    expect(invalidEmailAndPassword.message).toEqual(
+      'Password and email are invalid.'
+    );
+  });
+
+  it(`should return success for complex valid 
+    password with multiple specials and digits`, () => {
+    const result = validateRegisterForm('some@mail.com', 'P@ssw0rd!123$');
+
+    expect(result.code).toBe(200);
+    expect(result.message).toBe('Email and password are valid.');
+  });
 });