refactor: improve thinking logic

internal/thinking/errors_test.go

@@ -0,0 +1,34 @@
+// Package thinking provides unified thinking configuration processing logic.
+package thinking
+
+import "testing"
+
+// TestThinkingErrorError tests the Error() method of ThinkingError.
+//
+// Error() returns the message directly without code prefix.
+// Use Code field for programmatic error handling.
+func TestThinkingErrorError(t *testing.T) {
+	tests := []struct {
+		name     string
+		err      *ThinkingError
+		wantMsg  string
+		wantCode ErrorCode
+	}{
+		{"invalid suffix format", NewThinkingError(ErrInvalidSuffix, "invalid suffix format: model(abc"), "invalid suffix format: model(abc", ErrInvalidSuffix},
+		{"unknown level", NewThinkingError(ErrUnknownLevel, "unknown level: ultra"), "unknown level: ultra", ErrUnknownLevel},
+		{"level not supported", NewThinkingError(ErrLevelNotSupported, "level \"xhigh\" not supported, valid levels: low, medium, high"), "level \"xhigh\" not supported, valid levels: low, medium, high", ErrLevelNotSupported},
+		{"thinking not supported", NewThinkingErrorWithModel(ErrThinkingNotSupported, "thinking not supported for this model", "claude-haiku"), "thinking not supported for this model", ErrThinkingNotSupported},
+		{"provider mismatch", NewThinkingError(ErrProviderMismatch, "provider mismatch: expected claude, got gemini"), "provider mismatch: expected claude, got gemini", ErrProviderMismatch},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := tt.err.Error(); got != tt.wantMsg {
+				t.Errorf("Error() = %q, want %q", got, tt.wantMsg)
+			}
+			if tt.err.Code != tt.wantCode {
+				t.Errorf("Code = %q, want %q", tt.err.Code, tt.wantCode)
+			}
+		})
+	}
+}