Do not suppress diff if it is explicitly changed to zero (#3611)

Author: andrewnester

clusters/resource_cluster_test.go

@@ -1691,3 +1691,81 @@ func TestRefreshOnRunningClusterWithFailedLibraryUninstallsIt(t *testing.T) {
 		ID:   "foo",
 	}.ApplyNoError(t)
 }
+
+func TestResourceClusterUpdate_LocalSsdCount(t *testing.T) {
+	_, err := qa.ResourceFixture{
+		Fixtures: []qa.HTTPFixture{
+			{
+				Method:       "GET",
+				Resource:     "/api/2.0/clusters/get?cluster_id=abc",
+				ReuseRequest: true,
+				Response: compute.ClusterDetails{
+					ClusterId:              "abc",
+					NumWorkers:             100,
+					ClusterName:            "Non Autoscaling Cluster",
+					SparkVersion:           "7.1-scala12",
+					NodeTypeId:             "i3.xlarge",
+					AutoterminationMinutes: 15,
+					State:                  compute.StateTerminated,
+					GcpAttributes: &compute.GcpAttributes{
+						LocalSsdCount: 2,
+					},
+				},
+			},
+			{
+				Method:   "POST",
+				Resource: "/api/2.0/clusters/events",
+				ExpectedRequest: compute.GetEvents{
+					ClusterId:  "abc",
+					Limit:      1,
+					Order:      compute.GetEventsOrderDesc,
+					EventTypes: []compute.EventType{compute.EventTypePinned, compute.EventTypeUnpinned},
+				},
+				Response: compute.GetEventsResponse{
+					Events:     []compute.ClusterEvent{},
+					TotalCount: 0,
+				},
+			},
+			{
+				Method:   "POST",
+				Resource: "/api/2.0/clusters/edit",
+				ExpectedRequest: compute.ClusterDetails{
+					AutoterminationMinutes: 15,
+					ClusterId:              "abc",
+					NumWorkers:             100,
+					ClusterName:            "Non Autoscaling Cluster",
+					SparkVersion:           "7.1-scala12",
+					NodeTypeId:             "i3.xlarge",
+					GcpAttributes: &compute.GcpAttributes{
+						LocalSsdCount: 0,
+					},
+				},
+			},
+		},
+		ID:       "abc",
+		Update:   true,
+		Resource: ResourceCluster(),
+		InstanceState: map[string]string{
+			"autotermination_minutes": "15",
+			"cluster_name":            "Shared Autoscaling",
+			"spark_version":           "7.1-scala12",
+			"node_type_id":            "i3.xlarge",
+			"num_workers":             "100",
+			"gcp_attributes": `"{
+				local_ssd_count = 2
+			}"`,
+		},
+		HCL: `
+		autotermination_minutes = 15,
+		cluster_name =            "Non Autoscaling Cluster"
+		spark_version =           "7.1-scala12"
+		node_type_id =            "i3.xlarge"
+		num_workers =             100
+		gcp_attributes = {
+			local_ssd_count = 0
+		},
+		`,
+	}.Apply(t)
+
+	assert.NoError(t, err)
+}

common/reflect_resource.go

@@ -366,7 +366,9 @@ func chooseFieldName(typeField reflect.StructField) string {
 func diffSuppressor(fieldName string, v *schema.Schema) func(k, old, new string, d *schema.ResourceData) bool {
 	zero := fmt.Sprintf("%v", v.Type.Zero())
 	return func(k, old, new string, d *schema.ResourceData) bool {
-		if new == zero && old != zero {
+		// HasChange allows to check if the field is explicitly changed in the configuration.
+		// If the field is explicitly set in the configuration, we should not suppress the diff.
+		if new == zero && old != zero && !d.HasChange(k) {
 			log.Printf("[DEBUG] Suppressing diff for %v: platform=%#v config=%#v", k, old, new)
 			return true
 		}

common/reflect_resource_test.go

@@ -672,6 +672,36 @@ func TestDiffSuppressor(t *testing.T) {
 	assert.True(t, dsf("", "old", "", d))
 }
 
+func TestDiffSuppressorWhenNumberExplicitlyChangedToZero(t *testing.T) {
+	intSchema := &schema.Schema{
+		Type: schema.TypeInt,
+	}
+	dsf := diffSuppressor("foo", intSchema)
+	noChange := schema.TestResourceDataRaw(t, map[string]*schema.Schema{
+		"foo": {
+			Type:     schema.TypeInt,
+			Optional: true,
+		},
+	}, map[string]any{})
+	// no suppress
+	assert.False(t, dsf("foo", "1", "2", noChange))
+	// suppress
+	assert.True(t, dsf("foo", "1", "0", noChange))
+
+	change := schema.TestResourceDataRaw(t, map[string]*schema.Schema{
+		"foo": {
+			Type:     schema.TypeInt,
+			Optional: true,
+		},
+	}, map[string]any{
+		"foo": 1,
+	})
+
+	// no suppress
+	assert.False(t, dsf("foo", "1", "2", change))
+	assert.False(t, dsf("foo", "1", "0", change))
+}
+
 func TestTypeToSchemaNoStruct(t *testing.T) {
 	defer func() {
 		p := recover()