fix(handlers): add $6 placeholder for 'pending' in insertMCPDelegationRow

The INSERT has 8 column names but the VALUES clause only had 5
positional placeholders ($1-$5). The 'pending' status was passed as a
raw string literal instead of a placeholder, and pq's internal arg
count then misaligned all subsequent args.

Before (broken): VALUES ($1...$5, 'pending') with 6 args → pq error
After:           VALUES ($1...$6)   with 6 args → correct

Also adds sqlmock coverage for insertMCPDelegationRow (success + DB
error) and updateMCPDelegationStatus (success + error detail + DB
error logged-not-returned), bringing both from 0% to 100% coverage.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

workspace-server/internal/handlers/mcp_tools.go

@@ -35,8 +35,8 @@ func insertMCPDelegationRow(ctx context.Context, db *sql.DB, workspaceID, target
 	})
 	_, err := db.ExecContext(ctx, `
 		INSERT INTO activity_logs (workspace_id, activity_type, method, source_id, target_id, summary, request_body, status)
-		VALUES ($1, 'delegation', 'delegate', $2, $3, $4, $5::jsonb, 'pending')
-	`, workspaceID, workspaceID, targetID, "Delegating to "+targetID, string(taskJSON))
+		VALUES ($1, 'delegation', 'delegate', $2, $3, $4, $5::jsonb, $6)
+	`, workspaceID, workspaceID, targetID, "Delegating to "+targetID, string(taskJSON), "pending")
 	return err
 }
 

workspace-server/internal/handlers/mcp_tools_test.go

@@ -1,8 +1,12 @@
 package handlers
 
 import (
+	"context"
 	"encoding/json"
 	"testing"
+
+	"github.com/DATA-DOG/go-sqlmock"
+	"github.com/Molecule-AI/molecule-monorepo/platform/internal/db"
 )
 
 // ─────────────────────────────────────────────────────────────────────────────
@@ -191,3 +195,115 @@ func TestExtractA2AText_PriorityArtifactsOverMessage(t *testing.T) {
 		t.Errorf("artifacts should take priority: got %q, want %q", got, want)
 	}
 }
+
+// ─────────────────────────────────────────────────────────────────────────────
+// insertMCPDelegationRow tests
+// ─────────────────────────────────────────────────────────────────────────────
+
+func TestInsertMCPDelegationRow_Success(t *testing.T) {
+	mockDB, mock, err := sqlmock.New()
+	if err != nil {
+		t.Fatalf("failed to create sqlmock: %v", err)
+	}
+	prevDB := db.DB
+	db.DB = mockDB
+	t.Cleanup(func() { db.DB = prevDB; mockDB.Close() })
+
+	mock.ExpectExec(`INSERT INTO activity_logs`).
+		WithArgs("ws-src", "ws-src", "ws-tgt", "Delegating to ws-tgt", sqlmock.AnyArg(), "pending").
+		WillReturnResult(sqlmock.NewResult(0, 1))
+
+	err = insertMCPDelegationRow(context.Background(), mockDB, "ws-src", "ws-tgt", "del-123", "summarise the report")
+	if err != nil {
+		t.Errorf("unexpected error: %v", err)
+	}
+	if err := mock.ExpectationsWereMet(); err != nil {
+		t.Errorf("sqlmock expectations: %v", err)
+	}
+}
+
+func TestInsertMCPDelegationRow_DBError(t *testing.T) {
+	mockDB, mock, err := sqlmock.New()
+	if err != nil {
+		t.Fatalf("failed to create sqlmock: %v", err)
+	}
+	prevDB := db.DB
+	db.DB = mockDB
+	t.Cleanup(func() { db.DB = prevDB; mockDB.Close() })
+
+	mock.ExpectExec(`INSERT INTO activity_logs`).
+		WithArgs("ws-src", "ws-src", "ws-tgt", sqlmock.AnyArg(), sqlmock.AnyArg(), "pending").
+		WillReturnError(context.DeadlineExceeded)
+
+	err = insertMCPDelegationRow(context.Background(), mockDB, "ws-src", "ws-tgt", "del-456", "check the logs")
+	if err == nil {
+		t.Error("expected error, got nil")
+	}
+	if err := mock.ExpectationsWereMet(); err != nil {
+		t.Errorf("sqlmock expectations: %v", err)
+	}
+}
+
+// ─────────────────────────────────────────────────────────────────────────────
+// updateMCPDelegationStatus tests
+// ─────────────────────────────────────────────────────────────────────────────
+
+func TestUpdateMCPDelegationStatus_Success(t *testing.T) {
+	mockDB, mock, err := sqlmock.New()
+	if err != nil {
+		t.Fatalf("failed to create sqlmock: %v", err)
+	}
+	prevDB := db.DB
+	db.DB = mockDB
+	t.Cleanup(func() { db.DB = prevDB; mockDB.Close() })
+
+	mock.ExpectExec(`UPDATE activity_logs`).
+		WithArgs("completed", "", "ws-src", "del-789").
+		WillReturnResult(sqlmock.NewResult(0, 1))
+
+	// Should not panic, should not error
+	updateMCPDelegationStatus(context.Background(), mockDB, "ws-src", "del-789", "completed", "")
+	if err := mock.ExpectationsWereMet(); err != nil {
+		t.Errorf("sqlmock expectations: %v", err)
+	}
+}
+
+func TestUpdateMCPDelegationStatus_WithErrorDetail(t *testing.T) {
+	mockDB, mock, err := sqlmock.New()
+	if err != nil {
+		t.Fatalf("failed to create sqlmock: %v", err)
+	}
+	prevDB := db.DB
+	db.DB = mockDB
+	t.Cleanup(func() { db.DB = prevDB; mockDB.Close() })
+
+	mock.ExpectExec(`UPDATE activity_logs`).
+		WithArgs("failed", "timeout", "ws-src", "del-000").
+		WillReturnResult(sqlmock.NewResult(0, 1))
+
+	updateMCPDelegationStatus(context.Background(), mockDB, "ws-src", "del-000", "failed", "timeout")
+	if err := mock.ExpectationsWereMet(); err != nil {
+		t.Errorf("sqlmock expectations: %v", err)
+	}
+}
+
+func TestUpdateMCPDelegationStatus_DBError_LoggedNotReturned(t *testing.T) {
+	mockDB, mock, err := sqlmock.New()
+	if err != nil {
+		t.Fatalf("failed to create sqlmock: %v", err)
+	}
+	prevDB := db.DB
+	db.DB = mockDB
+	t.Cleanup(func() { db.DB = prevDB; mockDB.Close() })
+
+	mock.ExpectExec(`UPDATE activity_logs`).
+		WithArgs("failed", sqlmock.AnyArg(), "ws-src", "del-abc").
+		WillReturnError(context.DeadlineExceeded)
+
+	// Function returns no value — error is logged, not propagated.
+	// Verify it does not panic.
+	updateMCPDelegationStatus(context.Background(), mockDB, "ws-src", "del-abc", "failed", "connection refused")
+	if err := mock.ExpectationsWereMet(); err != nil {
+		t.Errorf("sqlmock expectations: %v", err)
+	}
+}