test: add tests for file metadata and range parameters

- testFileRange: test GetFileWithRange with various offset/limit values
- testDeclarationsWithMetadata: test file metadata in declarations
- Verify byte_size and line_count are computed correctly
- Test edge cases: offset beyond EOF, non-indexed files

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

internal/database/database_test.go

@@ -19,6 +19,8 @@ func runStoreTests(t *testing.T, newStore func(t *testing.T) Store) {
 		{"OptionChildren", testOptionChildren},
 		{"Declarations", testDeclarations},
 		{"Files", testFiles},
+		{"FileRange", testFileRange},
+		{"DeclarationsWithMetadata", testDeclarationsWithMetadata},
 		{"SchemaVersion", testSchemaVersion},
 	}
 
@@ -451,6 +453,14 @@ func testFiles(t *testing.T, store Store) {
 		t.Errorf("Extension = %q, want .nix", got.Extension)
 	}
 
+	// Verify file metadata was computed
+	if got.ByteSize != len(file.Content) {
+		t.Errorf("ByteSize = %d, want %d", got.ByteSize, len(file.Content))
+	}
+	if got.LineCount != 3 {
+		t.Errorf("LineCount = %d, want 3", got.LineCount)
+	}
+
 	// Get non-existent file
 	got, err = store.GetFile(ctx, rev.ID, "nonexistent.nix")
 	if err != nil {
@@ -476,6 +486,169 @@ func testFiles(t *testing.T, store Store) {
 	}
 }
 
+func testFileRange(t *testing.T, store Store) {
+	ctx := context.Background()
+	if err := store.Initialize(ctx); err != nil {
+		t.Fatalf("Initialize failed: %v", err)
+	}
+
+	rev := &Revision{GitHash: "range123", ChannelName: "test"}
+	if err := store.CreateRevision(ctx, rev); err != nil {
+		t.Fatalf("CreateRevision failed: %v", err)
+	}
+
+	// Create a multi-line file
+	content := "line 1\nline 2\nline 3\nline 4\nline 5\nline 6\nline 7\nline 8\nline 9\nline 10"
+	file := &File{
+		RevisionID: rev.ID,
+		FilePath:   "multiline.nix",
+		Extension:  ".nix",
+		Content:    content,
+	}
+	if err := store.CreateFile(ctx, file); err != nil {
+		t.Fatalf("CreateFile failed: %v", err)
+	}
+
+	// Test default range (first 250 lines, but we have less)
+	result, err := store.GetFileWithRange(ctx, rev.ID, "multiline.nix", FileRange{})
+	if err != nil {
+		t.Fatalf("GetFileWithRange default failed: %v", err)
+	}
+	if result == nil {
+		t.Fatal("Expected result, got nil")
+	}
+	if result.TotalLines != 10 {
+		t.Errorf("TotalLines = %d, want 10", result.TotalLines)
+	}
+	if result.StartLine != 1 {
+		t.Errorf("StartLine = %d, want 1", result.StartLine)
+	}
+	if result.EndLine != 10 {
+		t.Errorf("EndLine = %d, want 10", result.EndLine)
+	}
+
+	// Test with offset
+	result, err = store.GetFileWithRange(ctx, rev.ID, "multiline.nix", FileRange{Offset: 2, Limit: 3})
+	if err != nil {
+		t.Fatalf("GetFileWithRange with offset failed: %v", err)
+	}
+	if result.StartLine != 3 {
+		t.Errorf("StartLine = %d, want 3", result.StartLine)
+	}
+	if result.EndLine != 5 {
+		t.Errorf("EndLine = %d, want 5", result.EndLine)
+	}
+	if result.Content != "line 3\nline 4\nline 5" {
+		t.Errorf("Content = %q, want lines 3-5", result.Content)
+	}
+
+	// Test offset beyond file
+	result, err = store.GetFileWithRange(ctx, rev.ID, "multiline.nix", FileRange{Offset: 100})
+	if err != nil {
+		t.Fatalf("GetFileWithRange beyond end failed: %v", err)
+	}
+	if result.StartLine != 0 {
+		t.Errorf("StartLine = %d, want 0 for beyond end", result.StartLine)
+	}
+	if result.Content != "" {
+		t.Errorf("Content = %q, want empty for beyond end", result.Content)
+	}
+
+	// Test non-existent file
+	result, err = store.GetFileWithRange(ctx, rev.ID, "nonexistent.nix", FileRange{})
+	if err != nil {
+		t.Fatalf("GetFileWithRange for nonexistent failed: %v", err)
+	}
+	if result != nil {
+		t.Error("Expected nil for nonexistent file")
+	}
+}
+
+func testDeclarationsWithMetadata(t *testing.T, store Store) {
+	ctx := context.Background()
+	if err := store.Initialize(ctx); err != nil {
+		t.Fatalf("Initialize failed: %v", err)
+	}
+
+	rev := &Revision{GitHash: "metadata123", ChannelName: "test"}
+	if err := store.CreateRevision(ctx, rev); err != nil {
+		t.Fatalf("CreateRevision failed: %v", err)
+	}
+
+	// Create a file
+	file := &File{
+		RevisionID: rev.ID,
+		FilePath:   "modules/nginx.nix",
+		Extension:  ".nix",
+		Content:    "line 1\nline 2\nline 3",
+	}
+	if err := store.CreateFile(ctx, file); err != nil {
+		t.Fatalf("CreateFile failed: %v", err)
+	}
+
+	// Create an option with declarations
+	opt := &Option{
+		RevisionID: rev.ID,
+		Name:       "services.nginx.enable",
+		ParentPath: "services.nginx",
+		Type:       "boolean",
+	}
+	if err := store.CreateOption(ctx, opt); err != nil {
+		t.Fatalf("CreateOption failed: %v", err)
+	}
+
+	// Create declarations - one pointing to indexed file, one to non-indexed
+	decls := []*Declaration{
+		{OptionID: opt.ID, FilePath: "modules/nginx.nix", Line: 10},
+		{OptionID: opt.ID, FilePath: "modules/other.nix", Line: 20},
+	}
+	if err := store.CreateDeclarationsBatch(ctx, decls); err != nil {
+		t.Fatalf("CreateDeclarationsBatch failed: %v", err)
+	}
+
+	// Get declarations with metadata
+	declMetas, err := store.GetDeclarationsWithMetadata(ctx, rev.ID, opt.ID)
+	if err != nil {
+		t.Fatalf("GetDeclarationsWithMetadata failed: %v", err)
+	}
+	if len(declMetas) != 2 {
+		t.Fatalf("Expected 2 declarations, got %d", len(declMetas))
+	}
+
+	// Find the declaration for the indexed file
+	var indexed, notIndexed *DeclarationWithMetadata
+	for _, d := range declMetas {
+		if d.FilePath == "modules/nginx.nix" {
+			indexed = d
+		} else {
+			notIndexed = d
+		}
+	}
+
+	if indexed == nil {
+		t.Fatal("Expected indexed declaration")
+	}
+	if !indexed.HasFile {
+		t.Error("Expected HasFile=true for indexed file")
+	}
+	if indexed.ByteSize != len(file.Content) {
+		t.Errorf("ByteSize = %d, want %d", indexed.ByteSize, len(file.Content))
+	}
+	if indexed.LineCount != 3 {
+		t.Errorf("LineCount = %d, want 3", indexed.LineCount)
+	}
+
+	if notIndexed == nil {
+		t.Fatal("Expected not-indexed declaration")
+	}
+	if notIndexed.HasFile {
+		t.Error("Expected HasFile=false for non-indexed file")
+	}
+	if notIndexed.ByteSize != 0 {
+		t.Errorf("ByteSize = %d, want 0 for non-indexed", notIndexed.ByteSize)
+	}
+}
+
 func testSchemaVersion(t *testing.T, store Store) {
 	ctx := context.Background()