Merge pull request 'test(handlers): add unit tests for extractToolTrace in a2a_proxy_helpers.go' (#446) from fix/test-extract-tool-trace into staging

workspace-server/internal/handlers/a2a_proxy_helpers_test.go

@@ -0,0 +1,163 @@
+package handlers
+
+// a2a_proxy_helpers_test.go — unit tests for extractToolTrace (the only
+// untested pure function in a2a_proxy_helpers.go). The function parses JSON
+// so tests use real JSON without any DB or HTTP mocking.
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/Molecule-AI/molecule-monorepo/platform/internal/db"
+)
+
+// TestExtractToolTrace_HappyPath verifies that a well-formed JSON-RPC result
+// with a metadata.tool_trace field returns it as json.RawMessage.
+func TestExtractToolTrace_HappyPath(t *testing.T) {
+	trace := json.RawMessage(`[{"tool":"bash","input":"ls"}]`)
+	resp := map[string]interface{}{
+		"result": map[string]interface{}{
+			"metadata": map[string]interface{}{
+				"tool_trace": trace,
+			},
+		},
+	}
+	body, _ := json.Marshal(resp)
+	got := extractToolTrace(body)
+	if got == nil {
+		t.Fatal("extractToolTrace returned nil, expected the trace")
+	}
+	var parsed []map[string]interface{}
+	if err := json.Unmarshal(got, &parsed); err != nil {
+		t.Fatalf("returned value is not valid JSON: %v", err)
+	}
+	if len(parsed) != 1 || parsed[0]["tool"] != "bash" {
+		t.Errorf("unexpected trace content: %v", parsed)
+	}
+}
+
+// TestExtractToolTrace_ResultUsageShape tests a result object that has usage
+// (common A2A response shape) but no tool_trace — should return nil.
+func TestExtractToolTrace_ResultHasUsageNoTrace(t *testing.T) {
+	resp := map[string]interface{}{
+		"result": map[string]interface{}{
+			"metadata": map[string]interface{}{
+				"usage": map[string]int64{"input_tokens": 100, "output_tokens": 200},
+			},
+		},
+	}
+	body, _ := json.Marshal(resp)
+	if got := extractToolTrace(body); got != nil {
+		t.Errorf("expected nil when no tool_trace, got: %s", string(got))
+	}
+}
+
+// TestExtractToolTrace_NoResultKey verifies that a response without a "result"
+// key returns nil.
+func TestExtractToolTrace_NoResultKey(t *testing.T) {
+	resp := map[string]interface{}{
+		"error": map[string]string{"code": "-32600", "message": "Invalid Request"},
+	}
+	body, _ := json.Marshal(resp)
+	if got := extractToolTrace(body); got != nil {
+		t.Errorf("expected nil for error response, got: %s", string(got))
+	}
+}
+
+// TestExtractToolTrace_ResultNotAnObject verifies that a result that is not
+// a JSON object (e.g., null) returns nil without panicking.
+func TestExtractToolTrace_ResultNotAnObject(t *testing.T) {
+	body := []byte(`{"result": null}`)
+	if got := extractToolTrace(body); got != nil {
+		t.Errorf("expected nil for null result, got: %s", string(got))
+	}
+}
+
+// TestExtractToolTrace_NoMetadata verifies that a result object without
+// metadata returns nil.
+func TestExtractToolTrace_NoMetadata(t *testing.T) {
+	resp := map[string]interface{}{
+		"result": map[string]interface{}{
+			"message": "hello",
+		},
+	}
+	body, _ := json.Marshal(resp)
+	if got := extractToolTrace(body); got != nil {
+		t.Errorf("expected nil for result without metadata, got: %s", string(got))
+	}
+}
+
+// TestExtractToolTrace_MetadataNotAnObject verifies that a metadata field that
+// is not a JSON object returns nil without panicking.
+func TestExtractToolTrace_MetadataNotAnObject(t *testing.T) {
+	resp := map[string]interface{}{
+		"result": map[string]interface{}{
+			"metadata": "not an object",
+		},
+	}
+	body, _ := json.Marshal(resp)
+	if got := extractToolTrace(body); got != nil {
+		t.Errorf("expected nil for non-object metadata, got: %s", string(got))
+	}
+}
+
+// TestExtractToolTrace_TraceIsEmptyArray verifies that an empty tool_trace
+// array ([]) returns nil (length 0).
+func TestExtractToolTrace_TraceIsEmptyArray(t *testing.T) {
+	resp := map[string]interface{}{
+		"result": map[string]interface{}{
+			"metadata": map[string]interface{}{
+				"tool_trace": []interface{}{},
+			},
+		},
+	}
+	body, _ := json.Marshal(resp)
+	if got := extractToolTrace(body); got != nil {
+		t.Errorf("expected nil for empty tool_trace, got: %s", string(got))
+	}
+}
+
+// TestExtractToolTrace_NonJSONBody verifies that a completely non-JSON body
+// returns nil without panicking.
+func TestExtractToolTrace_NonJSONBody(t *testing.T) {
+	body := []byte("this is not json at all")
+	if got := extractToolTrace(body); got != nil {
+		t.Errorf("expected nil for non-JSON body, got: %s", string(got))
+	}
+}
+
+// TestExtractToolTrace_EmptyBody verifies that an empty body returns nil.
+func TestExtractToolTrace_EmptyBody(t *testing.T) {
+	if got := extractToolTrace(nil); got != nil {
+		t.Errorf("expected nil for nil body, got: %s", string(got))
+	}
+	if got := extractToolTrace([]byte{}); got != nil {
+		t.Errorf("expected nil for empty body, got: %s", string(got))
+	}
+}
+
+// TestExtractToolTrace_ResultMetadataIsNotObject verifies that when
+// metadata exists but is not a JSON object (string), nil is returned.
+func TestExtractToolTrace_MetadataIsString(t *testing.T) {
+	body := []byte(`{"result":{"metadata":"oops"}}`)
+	if got := extractToolTrace(body); got != nil {
+		t.Errorf("expected nil for string metadata, got: %s", string(got))
+	}
+}
+
+// TestNilIfEmpty_Contract exercises the contract of nilIfEmpty so future
+// refactors can't silently break the call-sites in a2a_proxy_helpers.go.
+func TestNilIfEmpty_Contract(t *testing.T) {
+	if r := nilIfEmpty(""); r != nil {
+		t.Errorf("nilIfEmpty(\"\") = %p, want nil", r)
+	}
+	if r := nilIfEmpty("hello"); r == nil {
+		t.Fatal("nilIfEmpty(\"hello\") returned nil, want pointer to string")
+	} else if *r != "hello" {
+		t.Errorf("nilIfEmpty(\"hello\") = %q, want \"hello\"", *r)
+	}
+}
+
+// Suppress unused import warning — setupTestDB references db.DB but this file
+// only tests pure functions, so db is only needed transitively through helpers.
+var _ = db.DB