diff --git a/src/validateRegisterForm.test.js b/src/validateRegisterForm.test.js
index 6d86ab9..1005cb6 100644
--- a/src/validateRegisterForm.test.js
+++ b/src/validateRegisterForm.test.js
@@ -1,30 +1,143 @@
-'use strict';
+"use strict";
 
 describe(`Function 'validateRegisterForm':`, () => {
-  const validateRegisterForm = require('./validateRegisterForm');
+  const validateRegisterForm = require("./validateRegisterForm");
 
   it(`should be declared`, () => {
     expect(validateRegisterForm).toBeInstanceOf(Function);
   });
 
   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`, () => {
-    const isValid = validateRegisterForm('test@mail.com', 'P@ssword1!');
+  it(`success message for the valid input`, () => {
+    const isValid = validateRegisterForm("test@mail.com", "P@ssword1!");
 
     expect(isValid.code).toBe(200);
-    expect(isValid.message).toBe('Email and password are valid.');
+    expect(isValid.message).toBe("Email and password are valid.");
   });
 
-  it(`should return error for valid email and password without number`, () => {
-    const invalidPassword = validateRegisterForm('test@mail.com', 'P@ssword');
+  it(`email error for email with no english letters`, () => {
+    const isValid = validateRegisterForm("test@maєil.com", "P@ssword1!");
+
+    expect(isValid.code).toBe(422);
+    expect(isValid.message).toBe("Email is invalid.");
+  });
+
+  it(`success message for email with digits and characters`, () => {
+    const isValid = validateRegisterForm(
+      "Tf4st@m5hgil.co!^&%$5m.cj",
+      "P@ssword1!"
+    );
+
+    expect(isValid.code).toBe(200);
+    expect(isValid.message).toBe("Email and password are valid.");
+  });
+
+  it(`email error for email without @`, () => {
+    const isValid = validateRegisterForm("testmail.com", "P@ssword1!");
+
+    expect(isValid.code).toBe(422);
+    expect(isValid.message).toBe("Email is invalid.");
+  });
+
+  it(`email error for email with . at start`, () => {
+    const isValid = validateRegisterForm(".test@mail.com", "P@ssword1!");
+
+    expect(isValid.code).toBe(422);
+    expect(isValid.message).toBe("Email is invalid.");
+  });
+
+  it(`email error for email with double dots`, () => {
+    const isValid = validateRegisterForm("te..st@mail.com", "P@ssword1!");
+
+    expect(isValid.code).toBe(422);
+    expect(isValid.message).toBe("Email is invalid.");
+  });
+
+  it(`password 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.");
+  });
+
+  it(`password error for valid email and password without character`, () => {
+    const invalidPassword = validateRegisterForm("test@mail.com", "Password1");
+
+    expect(invalidPassword.code).toBe(422);
+    expect(invalidPassword.message).toBe("Password is invalid.");
+  });
+
+  it(`password error for valid email and password without uppercase letter.`, () => {
+    const invalidPassword = validateRegisterForm("test@mail.com", "p@assword1");
 
     expect(invalidPassword.code).toBe(422);
-    expect(invalidPassword.message).toBe('Password is invalid.');
+    expect(invalidPassword.message).toBe("Password is invalid.");
   });
 
-  // write more tests here
+  it(`invalid password.length > 16`, () => {
+    const invalidPassword = validateRegisterForm(
+      "test@mail.com",
+      "P@sswordhjkkh2###"
+    );
+
+    expect(invalidPassword.code).toBe(422);
+    expect(invalidPassword.message).toBe("Password is invalid.");
+  });
+
+  it(`invalid password.length < 8`, () => {
+    const invalidPassword = validateRegisterForm("test@mail.com", "P@s2###");
+
+    expect(invalidPassword.code).toBe(422);
+    expect(invalidPassword.message).toBe("Password is invalid.");
+  });
+
+  it(`email error for email without dot in domain`, () => {
+    const isValid = validateRegisterForm("test@mailcom", "P@ssword1!");
+
+    expect(isValid.code).toBe(422);
+    expect(isValid.message).toBe("Email is invalid.");
+  });
+
+  it(`error message if password and email are invalid`, () => {
+    const isValid = validateRegisterForm("test@mailcom", "p@ssword1!");
+
+    expect(isValid.code).toBe(500);
+    expect(isValid.message).toBe("Password and email are invalid.");
+  });
+
+  it(`email error with dot at the start of top-level domain`, () => {
+    const isValid = validateRegisterForm("test@.mail.com", "P@ssword1!");
+
+    expect(isValid.code).toBe(422);
+    expect(isValid.message).toBe("Email is invalid.");
+  });
+
+  it(`success with an email that ends with a dot `, () => {
+    const isValid = validateRegisterForm("test@mail.com.", "P@ssword1!");
+
+    expect(isValid.code).toBe(200);
+    expect(isValid.message).toBe("Email and password are valid.");
+  });
+
+   it(`email error with the local-part(username) ends a dot before @ symbol`, () => {
+     const isValid = validateRegisterForm("test.@mail.com.", "P@ssword1!");
+
+     expect(isValid.code).toBe(422);
+     expect(isValid.message).toBe("Email is invalid.");
+   });
+
+  it(`password with Cyrillic letters`, () => {
+    const invalidPassword = validateRegisterForm(
+      "test@mail.com",
+      "YЖ@sswыэъфйяord1"
+    );
+
+    expect(invalidPassword.code).toBe(200);
+    expect(invalidPassword.message).toBe("Email and password are valid.");
+  });
 });