dry run migration

backend/src/api/routes/__tests__/test_migration_routes.py

@@ -407,4 +407,104 @@ async def test_execute_migration_invalid_env_raises_400(_mock_env):
     assert exc.value.status_code == 400
 
 
+@pytest.mark.asyncio
+async def test_dry_run_migration_returns_diff_and_risk(db_session):
+    # @TEST_EDGE: missing_target_datasource -> validates high risk item generation
+    # @TEST_EDGE: breaking_reference -> validates high risk on missing dataset link
+    from src.api.routes.migration import dry_run_migration
+    from src.models.dashboard import DashboardSelection
+
+    env_source = MagicMock()
+    env_source.id = "src"
+    env_source.name = "Source"
+    env_source.url = "http://source"
+    env_source.username = "admin"
+    env_source.password = "admin"
+    env_source.verify_ssl = False
+    env_source.timeout = 30
+
+    env_target = MagicMock()
+    env_target.id = "tgt"
+    env_target.name = "Target"
+    env_target.url = "http://target"
+    env_target.username = "admin"
+    env_target.password = "admin"
+    env_target.verify_ssl = False
+    env_target.timeout = 30
+
+    cm = _make_sync_config_manager([env_source, env_target])
+    selection = DashboardSelection(
+        selected_ids=[42],
+        source_env_id="src",
+        target_env_id="tgt",
+        replace_db_config=False,
+        fix_cross_filters=True,
+    )
+
+    with patch("src.api.routes.migration.SupersetClient") as MockClient, \
+         patch("src.api.routes.migration.MigrationDryRunService") as MockService:
+        source_client = MagicMock()
+        target_client = MagicMock()
+        MockClient.side_effect = [source_client, target_client]
+
+        service_instance = MagicMock()
+        service_payload = {
+            "generated_at": "2026-02-27T00:00:00+00:00",
+            "selection": selection.model_dump(),
+            "selected_dashboard_titles": ["Sales"],
+            "diff": {
+                "dashboards": {"create": [], "update": [{"uuid": "dash-1"}], "delete": []},
+                "charts": {"create": [{"uuid": "chart-1"}], "update": [], "delete": []},
+                "datasets": {"create": [{"uuid": "dataset-1"}], "update": [], "delete": []},
+            },
+            "summary": {
+                "dashboards": {"create": 0, "update": 1, "delete": 0},
+                "charts": {"create": 1, "update": 0, "delete": 0},
+                "datasets": {"create": 1, "update": 0, "delete": 0},
+                "selected_dashboards": 1,
+            },
+            "risk": {
+                "score": 75,
+                "level": "high",
+                "items": [
+                    {"code": "missing_datasource"},
+                    {"code": "breaking_reference"},
+                ],
+            },
+        }
+        service_instance.run.return_value = service_payload
+        MockService.return_value = service_instance
+
+        result = await dry_run_migration(selection=selection, config_manager=cm, db=db_session, _=None)
+
+    assert result["summary"]["dashboards"]["update"] == 1
+    assert result["summary"]["charts"]["create"] == 1
+    assert result["summary"]["datasets"]["create"] == 1
+    assert result["risk"]["score"] > 0
+    assert any(item["code"] == "missing_datasource" for item in result["risk"]["items"])
+    assert any(item["code"] == "breaking_reference" for item in result["risk"]["items"])
+
+
+@pytest.mark.asyncio
+async def test_dry_run_migration_rejects_same_environment(db_session):
+    from src.api.routes.migration import dry_run_migration
+    from src.models.dashboard import DashboardSelection
+
+    env = MagicMock()
+    env.id = "same"
+    env.name = "Same"
+    env.url = "http://same"
+    env.username = "admin"
+    env.password = "admin"
+    env.verify_ssl = False
+    env.timeout = 30
+
+    cm = _make_sync_config_manager([env])
+    selection = DashboardSelection(selected_ids=[1], source_env_id="same", target_env_id="same")
+
+    with pytest.raises(HTTPException) as exc:
+        await dry_run_migration(selection=selection, config_manager=cm, db=db_session, _=None)
+    assert exc.value.status_code == 400
+
+
 # [/DEF:backend.src.api.routes.__tests__.test_migration_routes:Module]

backend/src/api/routes/migration.py

@@ -14,6 +14,7 @@ from ...core.database import get_db
 from ...models.dashboard import DashboardMetadata, DashboardSelection
 from ...core.superset_client import SupersetClient
 from ...core.logger import belief_scope
+from ...core.migration.dry_run_orchestrator import MigrationDryRunService
 from ...core.mapping_service import IdMappingService
 from ...models.mapping import ResourceMapping
 
@@ -83,6 +84,44 @@ async def execute_migration(
         raise HTTPException(status_code=500, detail=f"Failed to create migration task: {str(e)}")
 # [/DEF:execute_migration:Function]
 
+
+# [DEF:dry_run_migration:Function]
+# @PURPOSE: Build pre-flight diff and risk summary without applying migration.
+# @PRE: Selection and environments are valid.
+# @POST: Returns deterministic JSON diff and risk scoring.
+@router.post("/migration/dry-run", response_model=Dict[str, Any])
+async def dry_run_migration(
+    selection: DashboardSelection,
+    config_manager=Depends(get_config_manager),
+    db: Session = Depends(get_db),
+    _ = Depends(has_permission("plugin:migration", "EXECUTE"))
+):
+    with belief_scope("dry_run_migration"):
+        environments = config_manager.get_environments()
+    env_map = {env.id: env for env in environments}
+    source_env = env_map.get(selection.source_env_id)
+    target_env = env_map.get(selection.target_env_id)
+    if not source_env or not target_env:
+        raise HTTPException(status_code=400, detail="Invalid source or target environment")
+    if selection.source_env_id == selection.target_env_id:
+        raise HTTPException(status_code=400, detail="Source and target environments must be different")
+    if not selection.selected_ids:
+        raise HTTPException(status_code=400, detail="No dashboards selected for dry run")
+
+    service = MigrationDryRunService()
+    source_client = SupersetClient(source_env)
+    target_client = SupersetClient(target_env)
+    try:
+        return service.run(
+            selection=selection,
+            source_client=source_client,
+            target_client=target_client,
+            db=db,
+        )
+    except ValueError as exc:
+        raise HTTPException(status_code=500, detail=str(exc)) from exc
+# [/DEF:dry_run_migration:Function]
+
 # [DEF:get_migration_settings:Function]
 # @PURPOSE: Get current migration Cron string explicitly.
 @router.get("/migration/settings", response_model=Dict[str, str])
@@ -221,4 +260,4 @@ async def trigger_sync_now(
         }
 # [/DEF:trigger_sync_now:Function]
 
-# [/DEF:backend.src.api.routes.migration:Module]
+# [/DEF:backend.src.api.routes.migration:Module]