Merge pull request #19548 from hashicorp/b-helper-schema-NewComputed-propagation

helper/schema: Always propagate NewComputed for previously zero value primitive type attributes

helper/schema/resource_diff_test.go

@@ -599,6 +599,37 @@ func testDiffCases(t *testing.T, oldPrefix string, oldOffset int, computed bool)
 				},
 			},
 		},
+		resourceDiffTestCase{
+			Name: "NewComputed should always propagate",
+			Schema: map[string]*Schema{
+				"foo": &Schema{
+					Type:     TypeString,
+					Computed: true,
+				},
+			},
+			State: &terraform.InstanceState{
+				Attributes: map[string]string{
+					"foo": "",
+				},
+				ID: "pre-existing",
+			},
+			Config:   testConfig(t, map[string]interface{}{}),
+			Diff:     &terraform.InstanceDiff{Attributes: map[string]*terraform.ResourceAttrDiff{}},
+			Key:      "foo",
+			NewValue: "",
+			Expected: &terraform.InstanceDiff{
+				Attributes: func() map[string]*terraform.ResourceAttrDiff {
+					if computed {
+						return map[string]*terraform.ResourceAttrDiff{
+							"foo": &terraform.ResourceAttrDiff{
+								NewComputed: computed,
+							},
+						}
+					}
+					return map[string]*terraform.ResourceAttrDiff{}
+				}(),
+			},
+		},
 	}
 }
 

helper/schema/schema.go

@@ -1185,7 +1185,7 @@ func (m schemaMap) diffString(
 		return fmt.Errorf("%s: %s", k, err)
 	}
 
-	if os == ns && !all {
+	if os == ns && !all && !computed {
 		// They're the same value. If there old value is not blank or we
 		// have an ID, then return right away since we're already setup.
 		if os != "" || d.Id() != "" {
@@ -1193,7 +1193,7 @@ func (m schemaMap) diffString(
 		}
 
 		// Otherwise, only continue if we're computed
-		if !schema.Computed && !computed {
+		if !schema.Computed {
 			return nil
 		}
 	}

helper/schema/schema_test.go

@@ -3126,6 +3126,40 @@ func TestSchemaMap_Diff(t *testing.T) {
 			Err: false,
 		},
 
+		{
+			Name: "NewComputed should always propagate with CustomizeDiff",
+			Schema: map[string]*Schema{
+				"foo": &Schema{
+					Type:     TypeString,
+					Computed: true,
+				},
+			},
+
+			State: &terraform.InstanceState{
+				Attributes: map[string]string{
+					"foo": "",
+				},
+				ID: "pre-existing",
+			},
+
+			Config: map[string]interface{}{},
+
+			CustomizeDiff: func(d *ResourceDiff, meta interface{}) error {
+				d.SetNewComputed("foo")
+				return nil
+			},
+
+			Diff: &terraform.InstanceDiff{
+				Attributes: map[string]*terraform.ResourceAttrDiff{
+					"foo": &terraform.ResourceAttrDiff{
+						NewComputed: true,
+					},
+				},
+			},
+
+			Err: false,
+		},
+
 		{
 			Name: "vetoing a diff",
 			Schema: map[string]*Schema{