Add comprehensive test coverage across packages

New test files:
- api/http_test.go: HTTP client and error handling tests
- config/config_test.go: Configuration loading and validation tests
- middleware/security_test.go: Security middleware tests
- models/atom_test.go: Atom model and conversion tests

Expanded test coverage:
- api/todoist_test.go: Todoist API client tests
- api/trello_test.go: Trello API client tests
- auth/auth_test.go: Authentication and CSRF tests
- handlers/timeline_logic_test.go: Timeline building logic tests
- store/sqlite_test.go: SQLite store operations tests

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

1 files changed, 196 insertions, 0 deletions

diff --git a/internal/auth/auth_test.go b/internal/auth/auth_test.go
index 013a4aa..fbe582b 100644
--- a/internal/auth/auth_test.go
+++ b/internal/auth/auth_test.go
@@ -1,6 +1,7 @@
 package auth
 
 import (
+	"context"
 	"database/sql"
 	"errors"
 	"testing"
@@ -106,3 +107,198 @@ func TestCreateUser(t *testing.T) {
 		t.Errorf("there were unfulfilled expectations: %s", err)
 	}
 }
+
+func TestUserCount(t *testing.T) {
+	db, mock, err := sqlmock.New()
+	if err != nil {
+		t.Fatalf("an error '%s' was not expected when opening a stub database connection", err)
+	}
+	defer func() { _ = db.Close() }()
+
+	service := NewService(db)
+
+	rows := sqlmock.NewRows([]string{"count"}).AddRow(5)
+	mock.ExpectQuery("SELECT COUNT").WillReturnRows(rows)
+
+	count, err := service.UserCount()
+	if err != nil {
+		t.Errorf("expected no error, got %v", err)
+	}
+	if count != 5 {
+		t.Errorf("expected count 5, got %d", count)
+	}
+}
+
+func TestEnsureDefaultUser_NoUsers(t *testing.T) {
+	db, mock, err := sqlmock.New()
+	if err != nil {
+		t.Fatalf("an error '%s' was not expected when opening a stub database connection", err)
+	}
+	defer func() { _ = db.Close() }()
+
+	service := NewService(db)
+
+	// Expect count query (no users)
+	countRows := sqlmock.NewRows([]string{"count"}).AddRow(0)
+	mock.ExpectQuery("SELECT COUNT").WillReturnRows(countRows)
+
+	// Expect check if user exists
+	mock.ExpectQuery("SELECT id, username, password_hash, created_at FROM users WHERE username = ?").
+		WithArgs("admin").
+		WillReturnError(sql.ErrNoRows)
+
+	// Expect insert
+	mock.ExpectExec("INSERT INTO users").
+		WithArgs("admin", sqlmock.AnyArg()).
+		WillReturnResult(sqlmock.NewResult(1, 1))
+
+	// Expect retrieve created user
+	rows := sqlmock.NewRows([]string{"id", "username", "password_hash", "created_at"}).
+		AddRow(1, "admin", "hashedpassword", time.Now())
+	mock.ExpectQuery("SELECT id, username, password_hash, created_at FROM users WHERE id = ?").
+		WithArgs(1).
+		WillReturnRows(rows)
+
+	err = service.EnsureDefaultUser("admin", "password")
+	if err != nil {
+		t.Errorf("expected no error, got %v", err)
+	}
+
+	if err := mock.ExpectationsWereMet(); err != nil {
+		t.Errorf("there were unfulfilled expectations: %s", err)
+	}
+}
+
+func TestEnsureDefaultUser_UsersExist(t *testing.T) {
+	db, mock, err := sqlmock.New()
+	if err != nil {
+		t.Fatalf("an error '%s' was not expected when opening a stub database connection", err)
+	}
+	defer func() { _ = db.Close() }()
+
+	service := NewService(db)
+
+	// Expect count query (users exist)
+	countRows := sqlmock.NewRows([]string{"count"}).AddRow(1)
+	mock.ExpectQuery("SELECT COUNT").WillReturnRows(countRows)
+
+	// Should not create user when users exist
+	err = service.EnsureDefaultUser("admin", "password")
+	if err != nil {
+		t.Errorf("expected no error, got %v", err)
+	}
+
+	if err := mock.ExpectationsWereMet(); err != nil {
+		t.Errorf("there were unfulfilled expectations: %s", err)
+	}
+}
+
+func TestAuthenticate_WrongPassword(t *testing.T) {
+	db, mock, err := sqlmock.New()
+	if err != nil {
+		t.Fatalf("an error '%s' was not expected when opening a stub database connection", err)
+	}
+	defer func() { _ = db.Close() }()
+
+	service := NewService(db)
+
+	// Hash a different password
+	hash, _ := bcrypt.GenerateFromPassword([]byte("correctpassword"), bcrypt.DefaultCost)
+
+	rows := sqlmock.NewRows([]string{"id", "username", "password_hash", "created_at"}).
+		AddRow(1, "testuser", string(hash), time.Now())
+
+	mock.ExpectQuery("SELECT id, username, password_hash, created_at FROM users WHERE username = ?").
+		WithArgs("testuser").
+		WillReturnRows(rows)
+
+	// Try with wrong password
+	_, err = service.Authenticate("testuser", "wrongpassword")
+	if !errors.Is(err, ErrInvalidCredentials) {
+		t.Errorf("expected ErrInvalidCredentials, got %v", err)
+	}
+}
+
+func TestCreateUser_AlreadyExists(t *testing.T) {
+	db, mock, err := sqlmock.New()
+	if err != nil {
+		t.Fatalf("an error '%s' was not expected when opening a stub database connection", err)
+	}
+	defer func() { _ = db.Close() }()
+
+	service := NewService(db)
+
+	// User already exists
+	hash, _ := bcrypt.GenerateFromPassword([]byte("password"), bcrypt.DefaultCost)
+	rows := sqlmock.NewRows([]string{"id", "username", "password_hash", "created_at"}).
+		AddRow(1, "existinguser", string(hash), time.Now())
+
+	mock.ExpectQuery("SELECT id, username, password_hash, created_at FROM users WHERE username = ?").
+		WithArgs("existinguser").
+		WillReturnRows(rows)
+
+	_, err = service.CreateUser("existinguser", "password")
+	if !errors.Is(err, ErrUserExists) {
+		t.Errorf("expected ErrUserExists, got %v", err)
+	}
+}
+
+func TestGetUserByID(t *testing.T) {
+	db, mock, err := sqlmock.New()
+	if err != nil {
+		t.Fatalf("an error '%s' was not expected when opening a stub database connection", err)
+	}
+	defer func() { _ = db.Close() }()
+
+	service := NewService(db)
+
+	rows := sqlmock.NewRows([]string{"id", "username", "password_hash", "created_at"}).
+		AddRow(42, "testuser", "hashedpassword", time.Now())
+
+	mock.ExpectQuery("SELECT id, username, password_hash, created_at FROM users WHERE id = ?").
+		WithArgs(int64(42)).
+		WillReturnRows(rows)
+
+	user, err := service.GetUserByID(42)
+	if err != nil {
+		t.Errorf("expected no error, got %v", err)
+	}
+	if user.ID != 42 {
+		t.Errorf("expected user ID 42, got %d", user.ID)
+	}
+}
+
+func TestGetUserByID_NotFound(t *testing.T) {
+	db, mock, err := sqlmock.New()
+	if err != nil {
+		t.Fatalf("an error '%s' was not expected when opening a stub database connection", err)
+	}
+	defer func() { _ = db.Close() }()
+
+	service := NewService(db)
+
+	mock.ExpectQuery("SELECT id, username, password_hash, created_at FROM users WHERE id = ?").
+		WithArgs(int64(999)).
+		WillReturnError(sql.ErrNoRows)
+
+	_, err = service.GetUserByID(999)
+	if err == nil {
+		t.Error("expected error for non-existent user")
+	}
+}
+
+func TestGetCSRFTokenFromContext(t *testing.T) {
+	// Test with token in context
+	ctx := context.WithValue(context.Background(), ContextKeyCSRF, "test-token")
+	token := GetCSRFTokenFromContext(ctx)
+	if token != "test-token" {
+		t.Errorf("expected 'test-token', got '%s'", token)
+	}
+
+	// Test without token in context
+	emptyCtx := context.Background()
+	emptyToken := GetCSRFTokenFromContext(emptyCtx)
+	if emptyToken != "" {
+		t.Errorf("expected empty string, got '%s'", emptyToken)
+	}
+}