test: added TestGetUserByName, TestAddUserDuplicateName, TestAddUserL…

internal/users/users.go

@@ -1,10 +1,13 @@
 package users
 
 import (
+	"errors"
 	"fmt"
 	"net/mail"
 )
 
+var ErrNoResultFound = errors.New("no result found")
+
 type User struct {
 	FirstName string
 	LastName  string
@@ -24,7 +27,16 @@ func (m *Manager) AddUser(firstName string, lastName string, email string) error
 		return fmt.Errorf("invalid first name: %q", firstName)
 	}
 	if lastName == "" {
-		return fmt.Errorf("invalid last name:%q", lastName)
+		return fmt.Errorf("invalid last name: %q", lastName)
+	}
+
+	existinguser, err := m.GetUserByName(firstName, lastName)
+	if err != nil && !errors.Is(err, ErrNoResultFound) {
+		return fmt.Errorf("error getting user by name: %v", err)
+	}
+
+	if existinguser != nil {
+		return errors.New("user already exists")
 	}
 
 	parsedAddress, err := mail.ParseAddress(email)
@@ -42,3 +54,14 @@ func (m *Manager) AddUser(firstName string, lastName string, email string) error
 
 	return nil
 }
+
+func (m *Manager) GetUserByName(first string, last string) (*User, error) {
+	for i, user := range m.users {
+		if user.FirstName == first && user.LastName == last {
+			result := &m.users[i]
+			return result, nil
+		}
+	}
+
+	return nil, ErrNoResultFound
+}

internal/users/users_test.go

@@ -71,7 +71,7 @@ func TestAddUserFirstName(t *testing.T) {
 	testLastName := "smith"
 	testEmail, err := mail.ParseAddress("foo@bar.com")
 	if err != nil {
-		t.Errorf("no error returned when adding invalid email %v", err)
+		t.Errorf("no error returned when adding first name %v", err)
 	}
 
 	err = testManager.AddUser(testFirstName, testLastName, testEmail.String())
@@ -88,3 +88,132 @@ func TestAddUserFirstName(t *testing.T) {
 		t.Fatalf("bad test manager count: expected 1 user, got %v", len(testManager.users))
 	}
 }
+
+func TestAddUserLastName(t *testing.T) {
+	testManager := NewManager()
+
+	testFirstName := "jhon"
+	testLastName := ""
+	testEmail, err := mail.ParseAddress("foo@bar.com")
+	if err != nil {
+		t.Errorf("no error returned when adding last name %v", err)
+	}
+
+	err = testManager.AddUser(testFirstName, testLastName, testEmail.String())
+	if err == nil {
+		t.Errorf("no error returned or invalid email")
+	} else {
+		expectedErr := "invalid last name: \"\""
+		if err.Error() != expectedErr {
+			t.Errorf("error mismatch: expected %v, got %v", expectedErr, err)
+		}
+	}
+
+	if len(testManager.users) > 0 {
+		t.Fatalf("bad test manager count: expected 1 user, got %v", len(testManager.users))
+	}
+}
+
+func TestAddUserDuplicateName(t *testing.T) {
+	testManager := NewManager()
+
+	testFirstName := "jhon"
+	testLastName := "smith"
+	testEmail, err := mail.ParseAddress("foo@bar.com")
+	if err != nil {
+		t.Errorf("no error returned when adding duplicate name %v", err)
+	}
+
+	err = testManager.AddUser(testFirstName, testLastName, testEmail.String())
+	if err != nil {
+		t.Errorf("error creating user")
+	}
+
+	err = testManager.AddUser(testFirstName, testLastName, testEmail.String())
+	if err == nil {
+		t.Errorf("error creating duplicate user")
+	} else {
+		expectedErr := "user already exists"
+		if err.Error() != expectedErr {
+			t.Errorf("error mismatch: expected %v, got %v", expectedErr, err)
+		}
+	}
+
+	if len(testManager.users) != 1 {
+		t.Errorf("bad test manager count: expected %d user, got %d", 1, len(testManager.users))
+	}
+}
+
+func TestGetUserByName(t *testing.T) {
+	testManager := NewManager()
+
+	err := testManager.AddUser("foo", "bar", "f.foo@bar.com")
+	if err != nil {
+		t.Fatalf("error adding test user: %v", err)
+	}
+	err = testManager.AddUser("bari", "foo", "bar@bar.com")
+	if err != nil {
+		t.Fatalf("error adding test user: %v", err)
+	}
+	err = testManager.AddUser("barz", "foo", "barz@bar.com")
+	if err != nil {
+		t.Fatalf("error adding test user: %v", err)
+	}
+	err = testManager.AddUser("fozz", "foo", "fooz@bar.com")
+	if err != nil {
+		t.Fatalf("error adding test user: %v", err)
+	}
+
+	tests := map[string]struct {
+		first         string
+		last          string
+		expected      *User
+		expectedError error
+	}{
+		"simple lookup": {
+			first:         "foo",
+			last:          "bar",
+			expected:      &testManager.users[0],
+			expectedError: nil,
+		},
+		"last element lookup": {
+			first:         "bari",
+			last:          "foo",
+			expected:      &testManager.users[3],
+			expectedError: nil,
+		},
+		"no match lookup": {
+			first:         "rgdf",
+			last:          "rgter",
+			expected:      nil,
+			expectedError: ErrNoResultFound,
+		},
+		"partial match lookup": {
+			first:         "fozz",
+			last:          "fozz",
+			expected:      nil,
+			expectedError: ErrNoResultFound,
+		},
+		"empty first name": {
+			first:         "",
+			last:          "fozz",
+			expected:      nil,
+			expectedError: ErrNoResultFound,
+		},
+		"empty last name": {
+			first:         "fozz",
+			last:          "",
+			expected:      nil,
+			expectedError: ErrNoResultFound,
+		},
+	}
+
+	for name, test := range tests {
+		result, err := testManager.GetUserByName(test.first, test.last)
+		if err != test.expectedError {
+			t.Errorf("%s: invalid result:\nexpected: %v\ngot: %v", name, result, test.expected)
+			return
+		}
+	}
+
+}