[ENG-3815] feat(microsoft): Impl Delete Subscription

internal/datautils/lists.go

@@ -20,6 +20,32 @@ func (l IndexedLists[ID, V]) Add(bucket ID, objects ...V) {
 	l[bucket] = append(l[bucket], objects...)
 }
 
+// Remove will remove all elements in the list under the bucket matching the filter.
+// A bucket may have a list with no items. If you need to remove the bucket itself, do it explicitly.
+func (l IndexedLists[ID, V]) Remove(bucket ID, filter func(V) bool) {
+	items, exists := l[bucket]
+	if !exists || len(items) == 0 {
+		return
+	}
+
+	// Reuse underlying array to avoid allocations
+	filtered := items[:0]
+
+	for _, item := range items {
+		if !filter(item) {
+			filtered = append(filtered, item)
+		}
+	}
+
+	// Clear trailing references.
+	var zero V
+	for i := len(filtered); i < len(items); i++ {
+		items[i] = zero
+	}
+
+	l[bucket] = filtered
+}
+
 func (l NamedLists[V]) Add(bucket string, objects ...V) {
 	IndexedLists[string, V](l).Add(bucket, objects...)
 }

providers/microsoft/internal/subscriber/delete.go

@@ -2,11 +2,85 @@ package subscriber
 
 import (
 	"context"
+	"errors"
 	"net/http"
 
+	"github.com/amp-labs/connectors/common"
 	"github.com/amp-labs/connectors/providers/microsoft/internal/batch"
 )
 
+// DeleteSubscription removes all remote subscriptions for objects specified in previousResult.
+// Executes batch DELETE requests to Microsoft Graph, tolerating 404s (already deleted) as success.
+// Discards final state as delete operations are fire-and-forget; returns first error if any.
+// https://learn.microsoft.com/en-us/graph/change-notifications-delivery-webhooks?tabs=http#delete-a-subscription
+func (s Strategy) DeleteSubscription(
+	ctx context.Context,
+	previousResult common.SubscriptionResult,
+) error {
+	remoteSubscriptions, err := s.fetchSubscriptions(ctx)
+	if err != nil {
+		return err
+	}
+
+	subscriptionsForRemoval := remoteSubscriptions.subset(previousResult.ObjectNames())
+
+	// The state is discarded.
+	_, err = s.deleteSubscriptions(ctx, subscriptionsForRemoval)
+
+	return err
+}
+
+// deleteSubscriptions batch-deletes all subscriptions in the given RemoteSubscriptions set.
+// Handles 404 responses as success (already deleted); aggregates other errors.
+//
+// Returns updated SubscriptionResult reflecting remaining subscriptions and operation status.
+func (s Strategy) deleteSubscriptions(
+	ctx context.Context,
+	remoteSubscriptions RemoteSubscriptions,
+) (*common.SubscriptionResult, error) {
+	subscriptionsToRemove := remoteSubscriptions.getIDs()
+
+	batchParams, err := s.paramsForBatchRemoveSubscriptionsByIDs(subscriptionsToRemove)
+	if err != nil {
+		return nil, err
+	}
+
+	bundledResponse := batch.Execute[SubscriptionResource](ctx, s.batchStrategy, batchParams)
+
+	// Aggregate non-404 errors (404 indicates record was already deleted).
+	var outErr error
+
+	for _, e := range bundledResponse.Errors {
+		if e.Status != http.StatusNotFound {
+			// Resource no longer exists.
+		} else {
+			outErr = errors.Join(outErr, e.Data)
+		}
+	}
+
+	// Filter out the subscription that were removed if any are left .
+	for requestID, resp := range bundledResponse.Responses {
+		name := ObjectName(resp.Data.Resource)
+		RemoteSubsType(remoteSubscriptions).Remove(name, func(subscription SubscriptionResource) bool {
+			return subscription.ID == SubscriptionID(requestID)
+		})
+	}
+
+	status := common.SubscriptionStatusSuccess
+	if outErr != nil {
+		// The rollback does not happen for delete. So it is either Success or Failure.
+		status = common.SubscriptionStatusFailed
+	}
+
+	return &common.SubscriptionResult{
+		Result:       Output{},
+		ObjectEvents: remoteSubscriptions.toState(),
+		Status:       status,
+	}, outErr
+}
+
+// removeSubscriptionsByIDs executes batch DELETE for given subscription IDs.
+// Generic helper; returns raw batch result for custom error handling.
 func (s Strategy) removeSubscriptionsByIDs(
 	ctx context.Context, identifiers []SubscriptionID,
 ) (*batch.Result[any], error) {
@@ -20,6 +94,7 @@ func (s Strategy) removeSubscriptionsByIDs(
 	return bundledResponse, nil
 }
 
+// paramsForBatchRemoveSubscriptionsByIDs creates batch parameters for DELETE `/subscriptions/{id}` requests.
 func (s Strategy) paramsForBatchRemoveSubscriptionsByIDs(identifiers []SubscriptionID) (*batch.Params, error) {
 	batchParams := &batch.Params{}
 

providers/microsoft/internal/subscriber/delete_test.go

@@ -0,0 +1,64 @@
+package subscriber
+
+import (
+	"net/http"
+	"testing"
+
+	"github.com/amp-labs/connectors/common"
+	"github.com/amp-labs/connectors/internal/components"
+	"github.com/amp-labs/connectors/test/utils/mockutils/mockcond"
+	"github.com/amp-labs/connectors/test/utils/mockutils/mockserver"
+	"github.com/amp-labs/connectors/test/utils/testroutines"
+	"github.com/amp-labs/connectors/test/utils/testutils"
+)
+
+func TestDelete(t *testing.T) { // nolint:funlen,cyclop
+	t.Parallel()
+
+	responseReadSubscriptions := testutils.DataFromFile(t, "read/subscriptions-response.json")
+	responseDeleteSubscriptions := testutils.DataFromFile(t, "delete/subscriptions-response.json")
+	deleteMessage1 := testutils.DataFromFile(t, "delete/payload-message-1.json")
+	deleteMessage2 := testutils.DataFromFile(t, "delete/payload-message-2.json")
+	deleteMessage3 := testutils.DataFromFile(t, "delete/payload-message-3.json")
+
+	tests := []testroutines.DeleteSubscription{
+		{
+			Name: "Successfully remove subscriptions to Outlook messages.",
+			Input: common.SubscriptionResult{
+				ObjectEvents: map[ObjectName]common.ObjectEvents{
+					"me/messages": {},
+				},
+			},
+			Server: mockserver.Switch{
+				Setup: mockserver.ContentJSON(),
+				Cases: mockserver.Cases{{
+					If: mockcond.And{
+						mockcond.MethodGET(),
+						mockcond.Path("/v1.0/subscriptions"),
+					},
+					Then: mockserver.Response(http.StatusOK, responseReadSubscriptions),
+				}, {
+					If: mockcond.And{
+						mockcond.MethodPOST(),
+						mockcond.Path("/v1.0/$batch"),
+						payloadBatchRequests(deleteMessage1, deleteMessage2, deleteMessage3),
+					},
+					Then: mockserver.Response(http.StatusNoContent, responseDeleteSubscriptions),
+				}},
+			}.Server(),
+			Expected:     testroutines.None{},
+			ExpectedErrs: nil,
+		},
+	}
+
+	for _, tt := range tests { // nolint:dupl
+		// nolint:varnamelen
+		t.Run(tt.Name, func(t *testing.T) {
+			t.Parallel()
+
+			tt.Run(t, func() (components.SubscriptionRemover, error) {
+				return constructTestStrategy(tt.Server.URL)
+			})
+		})
+	}
+}

providers/microsoft/internal/subscriber/state.go

@@ -1,10 +1,18 @@
 package subscriber
 
 import (
+	"context"
+
 	"github.com/amp-labs/connectors/common"
+	"github.com/amp-labs/connectors/internal/datautils"
 )
 
 type (
+	// RemoteSubscriptions describes the actual state of subscriptions in the remote system.
+	// Each ObjectName maps to a list of remote SubscriptionResource items.
+	RemoteSubscriptions RemoteSubsType
+	RemoteSubsType      = datautils.IndexedLists[ObjectName, SubscriptionResource]
+
 	// State describes the set of object events that the connector should
 	// try to achieve (desired) and that are also reported back as the observed outcome.
 	//
@@ -22,3 +30,97 @@ func newState(objectNames []ObjectName) State {
 
 	return events
 }
+
+func (r RemoteSubscriptions) toState() State {
+	result := make(State)
+
+	for objectName, subscriptions := range r {
+		eventSet := datautils.NewSet[common.SubscriptionEventType]()
+
+		for _, subscription := range subscriptions {
+			eventSet.Add(subscription.ChangeType.EventTypes())
+		}
+
+		// List of events may be nil.
+		var events []common.SubscriptionEventType
+		if list := eventSet.List(); len(list) != 0 {
+			events = list
+		}
+
+		result[objectName] = common.ObjectEvents{
+			Events:            events,
+			WatchFields:       nil,
+			WatchFieldsAll:    false,
+			PassThroughEvents: nil,
+		}
+	}
+
+	return result
+}
+
+func (r RemoteSubscriptions) subset(objects []ObjectName) RemoteSubscriptions {
+	result := make(RemoteSubscriptions)
+
+	names := datautils.NewSetFromList(objects)
+	for name, subscriptions := range r {
+		if names.Has(name) {
+			for _, subscription := range subscriptions {
+				RemoteSubsType(result).Add(name, subscription)
+			}
+		}
+	}
+
+	return result
+}
+
+func (r RemoteSubscriptions) getIDs() []SubscriptionID {
+	result := make([]SubscriptionID, 0)
+
+	for _, subscriptions := range r {
+		for _, subscription := range subscriptions {
+			result = append(result, subscription.ID)
+		}
+	}
+
+	return result
+}
+
+// fetchSubscriptions retrieves the current Microsoft Graph change‑notification subscriptions for the given objects.
+//
+// nolint:lll
+// According to https://learn.microsoft.com/en-us/graph/change-notifications-delivery-webhooks?tabs=http#subscription-request,
+// Graph should guard against duplicate subscriptions (same changeType and resource), but in practice
+// multiple subscriptions for the same combination can exist. Therefore, before blindly creating,
+// updating, or deleting subscriptions, this method first reads the current state and allows the caller
+// to reconcile the desired vs. actual subscriptions.
+func (s Strategy) fetchSubscriptions(ctx context.Context) (RemoteSubscriptions, error) {
+	url, err := s.getSubscriptionURL()
+	if err != nil {
+		return nil, err
+	}
+
+	response, err := s.client.Get(ctx, url.String())
+	if err != nil {
+		return nil, err
+	}
+
+	subscriptions, err := common.UnmarshalJSON[subscriptionResources](response)
+	if err != nil {
+		return nil, err
+	}
+
+	result := make(RemoteSubscriptions)
+
+	for _, resource := range subscriptions.List {
+		objectName := ObjectName(resource.Resource)
+		RemoteSubsType(result).Add(objectName, resource)
+	}
+
+	return result, nil
+}
+
+// subscriptionResources is the output of "GET /subscriptions".
+// https://learn.microsoft.com/en-us/graph/api/subscription-list?view=graph-rest-1.0&tabs=http#response-1
+type subscriptionResources struct {
+	List []SubscriptionResource `json:"value"`
+}

providers/microsoft/internal/subscriber/test/delete/payload-message-1.json

@@ -0,0 +1,8 @@
+{
+  "id": "c27d2493-0518-48db-b994-6d43aa584355",
+  "method": "DELETE",
+  "url": "/subscriptions/c27d2493-0518-48db-b994-6d43aa584355",
+  "headers": {
+    "Content-Type": "application/json"
+  }
+}

providers/microsoft/internal/subscriber/test/delete/payload-message-2.json

@@ -0,0 +1,8 @@
+{
+  "id": "29772d64-ee45-4e64-ab82-481602e07bc2",
+  "method": "DELETE",
+  "url": "/subscriptions/29772d64-ee45-4e64-ab82-481602e07bc2",
+  "headers": {
+    "Content-Type": "application/json"
+  }
+}

providers/microsoft/internal/subscriber/test/delete/payload-message-3.json

@@ -0,0 +1,8 @@
+{
+  "id": "90b46999-27c7-4145-a409-a5ef18250522",
+  "method": "DELETE",
+  "url": "/subscriptions/90b46999-27c7-4145-a409-a5ef18250522",
+  "headers": {
+    "Content-Type": "application/json"
+  }
+}

providers/microsoft/internal/subscriber/test/delete/subscriptions-response.json

@@ -0,0 +1,12 @@
+{
+  "responses": [
+    {
+      "id": "09ac29ca-cb8b-4761-94ab-ce372fd6fce3",
+      "status": 204,
+      "headers": {
+        "Cache-Control": "no-cache"
+      },
+      "body": null
+    }
+  ]
+}