feat: comprehensive test suite (Phase 4.2) (#12)

internal/config/config_test.go

@@ -214,3 +214,76 @@ func TestParseDebugLevel(t *testing.T) {
 		}
 	}
 }
+
+func TestParseMaxDepthValid(t *testing.T) {
+cases := []string{"1", "20", "100"}
+for _, s := range cases {
+v, err := ParseMaxDepth(s)
+if err != nil {
+t.Errorf("ParseMaxDepth(%q) unexpected error: %v", s, err)
+}
+if v < 1 || v > 100 {
+t.Errorf("ParseMaxDepth(%q) = %d, out of range", s, v)
+}
+}
+}
+
+func TestParseMaxDepthInvalid(t *testing.T) {
+cases := []string{"0", "101", "notanumber"}
+for _, s := range cases {
+_, err := ParseMaxDepth(s)
+if err == nil {
+t.Errorf("ParseMaxDepth(%q): expected error", s)
+}
+if !errors.Is(err, ErrInvalidMaxDepth) {
+t.Errorf("ParseMaxDepth(%q): expected ErrInvalidMaxDepth, got %v", s, err)
+}
+}
+}
+
+func TestParseRetriesValid(t *testing.T) {
+cases := []string{"0", "5", "10"}
+for _, s := range cases {
+v, err := ParseRetries(s)
+if err != nil {
+t.Errorf("ParseRetries(%q) unexpected error: %v", s, err)
+}
+if v < 0 || v > 10 {
+t.Errorf("ParseRetries(%q) = %d, out of range", s, v)
+}
+}
+}
+
+func TestParseRetriesInvalid(t *testing.T) {
+cases := []string{"-1", "11", "notanumber"}
+for _, s := range cases {
+_, err := ParseRetries(s)
+if err == nil {
+t.Errorf("ParseRetries(%q): expected error", s)
+}
+if !errors.Is(err, ErrInvalidRetries) {
+t.Errorf("ParseRetries(%q): expected ErrInvalidRetries, got %v", s, err)
+}
+}
+}
+
+func TestValidateBadQueryType(t *testing.T) {
+cfg := DefaultConfig()
+cfg.QueryType = "BOGUS"
+if err := cfg.Validate(); !errors.Is(err, ErrInvalidQueryType) {
+t.Errorf("expected ErrInvalidQueryType, got %v", err)
+}
+}
+
+func TestDefaultConfigIsValid(t *testing.T) {
+cfg := DefaultConfig()
+if cfg.QueryType != "A" {
+t.Errorf("QueryType = %q, want A", cfg.QueryType)
+}
+if cfg.MaxDepth != 20 {
+t.Errorf("MaxDepth = %d, want 20", cfg.MaxDepth)
+}
+if cfg.Retries != 2 {
+t.Errorf("Retries = %d, want 2", cfg.Retries)
+}
+}