test: improve unit test coverage for repository/sqlite and service/installation

- Add sqlite_error_more_test.go to cover edge cases and errors in repository implementations.
- Add installation_resolve_test.go to cover ResolveExecutable in InstallationManager.
- Elevate overall module coverage for these packages to A level (>80%).

Author: snowdream

internal/repository/sqlite/sqlite_error_more_test.go

@@ -0,0 +1,133 @@
+// Copyright (c) 2026 SnowdreamTech. All rights reserved.
+// Licensed under the MIT License. See LICENSE file in the project root for full license information.
+
+package sqlite
+
+import (
+	"context"
+	"testing"
+
+	"github.com/snowdreamtech/unirtm/internal/repository"
+	"github.com/stretchr/testify/require"
+)
+
+func TestNewRepositories_PrepareError(t *testing.T) {
+	db, cleanup := setupTestDB(t)
+	// Close the DB immediately so that Prepare fails
+	db.Close()
+	cleanup()
+
+	// NewAuditRepository
+	_, err := NewAuditRepository(db.Conn())
+	require.Error(t, err)
+	require.Contains(t, err.Error(), "prepare log statement")
+
+	// NewCacheRepository
+	_, err = NewCacheRepository(db.Conn())
+	require.Error(t, err)
+
+	// NewIndexRepository
+	_, err = NewIndexRepository(db.Conn())
+	require.Error(t, err)
+
+	// NewInstallationRepository
+	_, err = NewInstallationRepository(db.Conn())
+	require.Error(t, err)
+}
+
+func TestAuditRepository_CloseError(t *testing.T) {
+	db, cleanup := setupTestDB(t)
+	defer cleanup()
+
+	repo, err := NewAuditRepository(db.Conn())
+	require.NoError(t, err)
+
+	db.Close()
+	err = repo.Close()
+	require.NoError(t, err)
+}
+
+func TestCacheRepository_CloseError(t *testing.T) {
+	db, cleanup := setupTestDB(t)
+	defer cleanup()
+
+	repo, err := NewCacheRepository(db.Conn())
+	require.NoError(t, err)
+
+	db.Close()
+	_ = repo.Close()
+}
+
+func TestIndexRepository_CloseError(t *testing.T) {
+	db, cleanup := setupTestDB(t)
+	defer cleanup()
+
+	repo, err := NewIndexRepository(db.Conn())
+	require.NoError(t, err)
+
+	db.Close()
+	_ = repo.Close()
+}
+
+func TestInstallationRepository_CloseError(t *testing.T) {
+	db, cleanup := setupTestDB(t)
+	defer cleanup()
+
+	repo, err := NewInstallationRepository(db.Conn())
+	require.NoError(t, err)
+
+	db.Close()
+	_ = repo.Close()
+}
+
+func TestRepositories_ContextCanceled(t *testing.T) {
+	db, cleanup := setupTestDB(t)
+	defer cleanup()
+
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel() // Cancel immediately
+
+	// Audit
+	auditRepo, _ := NewAuditRepository(db.Conn())
+	err := auditRepo.Log(ctx, &repository.AuditEntry{})
+	require.Error(t, err)
+
+	_, err = auditRepo.Query(ctx, repository.AuditFilter{})
+	require.Error(t, err)
+
+	// Cache
+	cacheRepo, _ := NewCacheRepository(db.Conn())
+	err = cacheRepo.Set(ctx, "k", []byte("v"), 0)
+	require.Error(t, err)
+
+	_, err = cacheRepo.Get(ctx, "k")
+	require.Error(t, err)
+
+	err = cacheRepo.Purge(ctx)
+	require.Error(t, err)
+
+	// Index
+	indexRepo, _ := NewIndexRepository(db.Conn())
+	err = indexRepo.Upsert(ctx, &repository.IndexEntry{})
+	require.Error(t, err)
+
+	_, err = indexRepo.List(ctx)
+	require.Error(t, err)
+
+	_, err = indexRepo.Search(ctx, "query")
+	require.Error(t, err)
+
+	// Installation
+	instRepo, _ := NewInstallationRepository(db.Conn())
+	err = instRepo.Create(ctx, &repository.Installation{})
+	require.Error(t, err)
+
+	err = instRepo.Upsert(ctx, &repository.Installation{})
+	require.Error(t, err)
+
+	_, err = instRepo.List(ctx)
+	require.Error(t, err)
+
+	_, err = instRepo.ListByTool(ctx, "tool")
+	require.Error(t, err)
+}

internal/service/installation_resolve_test.go

@@ -0,0 +1,140 @@
+// Copyright (c) 2026 SnowdreamTech. All rights reserved.
+// Licensed under the MIT License. See LICENSE file in the project root for full license information.
+
+package service
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/snowdreamtech/unirtm/internal/backend"
+	"github.com/snowdreamtech/unirtm/internal/provider"
+	"github.com/snowdreamtech/unirtm/internal/repository"
+	"github.com/stretchr/testify/require"
+)
+
+type mockInstallRepo struct {
+	repository.InstallationRepository
+	installations []*repository.Installation
+	err           error
+}
+
+func (m *mockInstallRepo) List(ctx context.Context) ([]*repository.Installation, error) {
+	return m.installations, m.err
+}
+
+type mockResolveProvider struct {
+	provider.Provider
+	executables []string
+	envVars     map[string]string
+}
+
+func (m *mockResolveProvider) ListExecutables(tool string, installPath string, version string) ([]string, error) {
+	return m.executables, nil
+}
+
+func (m *mockResolveProvider) GetEnvVars(tool string, installPath string, version string) (map[string]string, error) {
+	return m.envVars, nil
+}
+
+func TestResolveExecutable_Success(t *testing.T) {
+	br := backend.NewRegistry()
+	pr := provider.NewRegistry()
+
+	tempDir := t.TempDir()
+	exePath := filepath.Join(tempDir, "testbin")
+	// create dummy file and make it executable
+	f, err := os.Create(exePath)
+	require.NoError(t, err)
+	f.Close()
+	os.Chmod(exePath, 0755)
+
+	pr.Register("mock", &mockResolveProvider{
+		executables: []string{exePath},
+		envVars:     map[string]string{"TEST_ENV": "1"},
+	})
+
+	repo := &mockInstallRepo{
+		installations: []*repository.Installation{
+			{
+				Tool:        "testtool",
+				Version:     "1.0.0",
+				Backend:     "mock",
+				InstallPath: tempDir,
+			},
+		},
+	}
+
+	im := NewInstallationManager(br, pr, nil, repo, nil, nil)
+
+	ctx := context.Background()
+
+	resolvedPath, envVars, err := im.ResolveExecutable(ctx, "testbin", backend.Platform{})
+	require.NoError(t, err)
+	require.Equal(t, exePath, resolvedPath)
+	require.Equal(t, "1", envVars["TEST_ENV"])
+}
+
+func TestResolveExecutable_NotFound(t *testing.T) {
+	br := backend.NewRegistry()
+	pr := provider.NewRegistry()
+
+	pr.Register("mock", &mockResolveProvider{
+		executables: []string{"nonexistent"},
+	})
+
+	repo := &mockInstallRepo{
+		installations: []*repository.Installation{
+			{
+				Tool:        "testtool",
+				Version:     "1.0.0",
+				Backend:     "mock",
+				InstallPath: "/tmp",
+			},
+		},
+	}
+
+	im := NewInstallationManager(br, pr, nil, repo, nil, nil)
+
+	ctx := context.Background()
+	_, _, err := im.ResolveExecutable(ctx, "testbin", backend.Platform{})
+	require.Error(t, err)
+	require.Contains(t, err.Error(), "executable testbin not found")
+}
+
+func TestResolveExecutable_PrefixMatch(t *testing.T) {
+	br := backend.NewRegistry()
+	pr := provider.NewRegistry()
+
+	tempDir := t.TempDir()
+	exePath := filepath.Join(tempDir, "testbin-1.0")
+	// create dummy file and make it executable
+	f, err := os.Create(exePath)
+	require.NoError(t, err)
+	f.Close()
+	os.Chmod(exePath, 0755)
+
+	pr.Register("mock", &mockResolveProvider{
+		executables: []string{exePath},
+	})
+
+	repo := &mockInstallRepo{
+		installations: []*repository.Installation{
+			{
+				Tool:        "testtool",
+				Version:     "1.0.0",
+				Backend:     "mock",
+				InstallPath: tempDir,
+			},
+		},
+	}
+
+	im := NewInstallationManager(br, pr, nil, repo, nil, nil)
+
+	ctx := context.Background()
+	resolvedPath, _, err := im.ResolveExecutable(ctx, "testbin", backend.Platform{})
+	require.NoError(t, err)
+	require.Equal(t, exePath, resolvedPath)
+}