Merge pull request #18795 from hashicorp/paddy_diff_nested_checkKey

Allow for nested fields with checkKey on ResourceDiffs.

helper/schema/resource_diff.go

@@ -231,7 +231,7 @@ func (d *ResourceDiff) UpdatedKeys() []string {
 // Note that this does not wipe an override. This function is only allowed on
 // computed keys.
 func (d *ResourceDiff) Clear(key string) error {
-	if err := d.checkKey(key, "Clear"); err != nil {
+	if err := d.checkKey(key, "Clear", true); err != nil {
 		return err
 	}
 
@@ -287,7 +287,7 @@ func (d *ResourceDiff) diffChange(key string) (interface{}, interface{}, bool, b
 //
 // This function is only allowed on computed attributes.
 func (d *ResourceDiff) SetNew(key string, value interface{}) error {
-	if err := d.checkKey(key, "SetNew"); err != nil {
+	if err := d.checkKey(key, "SetNew", false); err != nil {
 		return err
 	}
 
@@ -299,7 +299,7 @@ func (d *ResourceDiff) SetNew(key string, value interface{}) error {
 //
 // This function is only allowed on computed attributes.
 func (d *ResourceDiff) SetNewComputed(key string) error {
-	if err := d.checkKey(key, "SetNewComputed"); err != nil {
+	if err := d.checkKey(key, "SetNewComputed", false); err != nil {
 		return err
 	}
 
@@ -535,12 +535,24 @@ func childAddrOf(child, parent string) bool {
 }
 
 // checkKey checks the key to make sure it exists and is computed.
-func (d *ResourceDiff) checkKey(key, caller string) error {
+func (d *ResourceDiff) checkKey(key, caller string, nested bool) error {
+	var schema *Schema
+	if nested {
+		keyParts := strings.Split(key, ".")
+		schemaL := addrToSchema(keyParts, d.schema)
+		if len(schemaL) > 0 {
+			schema = schemaL[len(schemaL)-1]
+		}
+	} else {
 		s, ok := d.schema[key]
-	if !ok {
+		if ok {
+			schema = s
+		}
+	}
+	if schema == nil {
 		return fmt.Errorf("%s: invalid key: %s", caller, key)
 	}
-	if !s.Computed {
+	if !schema.Computed {
 		return fmt.Errorf("%s only operates on computed keys - %s is not one", caller, key)
 	}
 	return nil

helper/schema/resource_diff_test.go

@@ -1028,6 +1028,111 @@ func TestClear(t *testing.T) {
 				},
 			},
 		},
+		resourceDiffTestCase{
+			Name: "basic sub-block diff",
+			Schema: map[string]*Schema{
+				"foo": &Schema{
+					Type:     TypeList,
+					Optional: true,
+					Computed: true,
+					Elem: &Resource{
+						Schema: map[string]*Schema{
+							"bar": &Schema{
+								Type:     TypeString,
+								Optional: true,
+								Computed: true,
+							},
+							"baz": &Schema{
+								Type:     TypeString,
+								Optional: true,
+								Computed: true,
+							},
+						},
+					},
+				},
+			},
+			State: &terraform.InstanceState{
+				Attributes: map[string]string{
+					"foo.0.bar": "bar1",
+					"foo.0.baz": "baz1",
+				},
+			},
+			Config: testConfig(t, map[string]interface{}{
+				"foo": []map[string]interface{}{
+					map[string]interface{}{
+						"bar": "bar2",
+						"baz": "baz1",
+					},
+				},
+			}),
+			Diff: &terraform.InstanceDiff{
+				Attributes: map[string]*terraform.ResourceAttrDiff{
+					"foo.0.bar": &terraform.ResourceAttrDiff{
+						Old: "bar1",
+						New: "bar2",
+					},
+				},
+			},
+			Key:      "foo.0.bar",
+			Expected: &terraform.InstanceDiff{Attributes: map[string]*terraform.ResourceAttrDiff{}},
+		},
+		resourceDiffTestCase{
+			Name: "sub-block diff only partial clear",
+			Schema: map[string]*Schema{
+				"foo": &Schema{
+					Type:     TypeList,
+					Optional: true,
+					Computed: true,
+					Elem: &Resource{
+						Schema: map[string]*Schema{
+							"bar": &Schema{
+								Type:     TypeString,
+								Optional: true,
+								Computed: true,
+							},
+							"baz": &Schema{
+								Type:     TypeString,
+								Optional: true,
+								Computed: true,
+							},
+						},
+					},
+				},
+			},
+			State: &terraform.InstanceState{
+				Attributes: map[string]string{
+					"foo.0.bar": "bar1",
+					"foo.0.baz": "baz1",
+				},
+			},
+			Config: testConfig(t, map[string]interface{}{
+				"foo": []map[string]interface{}{
+					map[string]interface{}{
+						"bar": "bar2",
+						"baz": "baz2",
+					},
+				},
+			}),
+			Diff: &terraform.InstanceDiff{
+				Attributes: map[string]*terraform.ResourceAttrDiff{
+					"foo.0.bar": &terraform.ResourceAttrDiff{
+						Old: "bar1",
+						New: "bar2",
+					},
+					"foo.0.baz": &terraform.ResourceAttrDiff{
+						Old: "baz1",
+						New: "baz2",
+					},
+				},
+			},
+			Key: "foo.0.bar",
+			Expected: &terraform.InstanceDiff{Attributes: map[string]*terraform.ResourceAttrDiff{
+				"foo.0.baz": &terraform.ResourceAttrDiff{
+					Old: "baz1",
+					New: "baz2",
+				},
+			}},
+		},
 	}
 	for _, tc := range cases {
 		t.Run(tc.Name, func(t *testing.T) {