Add function to check TypeSet pairs

aws/internal/tfawsresource/testing.go

@@ -31,17 +31,11 @@ const (
 // Please note, if the provided value map is not granular enough, there exists
 // the possibility you match an element you were not intending to, in the TypeSet.
 // Provide a full mapping of attributes to be sure the unique element exists.
-func TestCheckTypeSetElemNestedAttrs(res, attr string, values map[string]string) resource.TestCheckFunc {
+func TestCheckTypeSetElemNestedAttrs(name, attr string, values map[string]string) resource.TestCheckFunc {
 	return func(s *terraform.State) error {
-		ms := s.RootModule()
-		rs, ok := ms.Resources[res]
-		if !ok {
-			return fmt.Errorf("Not found: %s in %s", res, ms.Path)
-		}
-
-		is := rs.Primary
-		if is == nil {
-			return fmt.Errorf("No primary instance: %s in %s", res, ms.Path)
+		is, err := instanceState(s, name)
+		if err != nil {
+			return err
 		}
 
 		matches := make(map[string]int)
@@ -91,7 +85,7 @@ func TestCheckTypeSetElemNestedAttrs(res, attr string, values map[string]string)
 			}
 		}
 
-		return fmt.Errorf("%q no TypeSet element %q, with nested attrs %#v in state: %#v", res, attr, values, is.Attributes)
+		return fmt.Errorf("%q no TypeSet element %q, with nested attrs %#v in state: %#v", name, attr, values, is.Attributes)
 	}
 }
 
@@ -102,39 +96,85 @@ func TestCheckTypeSetElemNestedAttrs(res, attr string, values map[string]string)
 //
 // Use this function over SDK provided TestCheckFunctions when validating a
 // TypeSet where its elements are a simple value
-func TestCheckTypeSetElemAttr(res, attr, value string) resource.TestCheckFunc {
+func TestCheckTypeSetElemAttr(name, attr, value string) resource.TestCheckFunc {
 	return func(s *terraform.State) error {
-		ms := s.RootModule()
-		rs, ok := ms.Resources[res]
-		if !ok {
-			return fmt.Errorf("Not found: %s in %s", res, ms.Path)
+		is, err := instanceState(s, name)
+		if err != nil {
+			return err
 		}
 
-		is := rs.Primary
-		if is == nil {
-			return fmt.Errorf("No primary instance: %s in %s", res, ms.Path)
+		err = testCheckTypeSetElem(is, attr, value)
+		if err != nil {
+			return fmt.Errorf("%q error: %s", name, err)
 		}
 
-		attrParts := strings.Split(attr, ".")
-		if attrParts[len(attrParts)-1] != sentinelIndex {
-			return fmt.Errorf("%q does not end with the special value %q", attr, sentinelIndex)
+		return nil
+	}
+}
+
+// TestCheckTypeSetElemAttrPair is a TestCheckFunc that verifies a pair of name/key
+// combinations are equal where the first uses the sentinel value to index into a
+// TypeSet.
+//
+// E.g., tfawsresource.TestCheckTypeSetElemAttrPair("aws_autoscaling_group.bar", "availability_zones.*", "data.aws_availability_zones.available", "names.0")
+func TestCheckTypeSetElemAttrPair(nameFirst, keyFirst, nameSecond, keySecond string) resource.TestCheckFunc {
+	return func(s *terraform.State) error {
+		isFirst, err := instanceState(s, nameFirst)
+		if err != nil {
+			return err
 		}
-		for stateKey, stateValue := range is.Attributes {
-			if stateValue == value {
-				stateKeyParts := strings.Split(stateKey, ".")
-				if len(stateKeyParts) == len(attrParts) {
-					for i := range attrParts {
-						if attrParts[i] != stateKeyParts[i] && attrParts[i] != sentinelIndex {
-							break
-						}
-						if i == len(attrParts)-1 {
-							return nil
-						}
+
+		isSecond, err := instanceState(s, nameSecond)
+		if err != nil {
+			return err
+		}
+
+		vSecond, okSecond := isSecond.Attributes[keySecond]
+		if !okSecond {
+			return fmt.Errorf("%s: Attribute %q not set, cannot be checked against TypeSet", nameSecond, keySecond)
+		}
+
+		return testCheckTypeSetElem(isFirst, keyFirst, vSecond)
+	}
+}
+
+// instanceState returns the primary instance state for the given
+// resource name in the root module.
+func instanceState(s *terraform.State, name string) (*terraform.InstanceState, error) {
+	ms := s.RootModule()
+	rs, ok := ms.Resources[name]
+	if !ok {
+		return nil, fmt.Errorf("Not found: %s in %s", name, ms.Path)
+	}
+
+	is := rs.Primary
+	if is == nil {
+		return nil, fmt.Errorf("No primary instance: %s in %s", name, ms.Path)
+	}
+
+	return is, nil
+}
+
+func testCheckTypeSetElem(is *terraform.InstanceState, attr, value string) error {
+	attrParts := strings.Split(attr, ".")
+	if attrParts[len(attrParts)-1] != sentinelIndex {
+		return fmt.Errorf("%q does not end with the special value %q", attr, sentinelIndex)
+	}
+	for stateKey, stateValue := range is.Attributes {
+		if stateValue == value {
+			stateKeyParts := strings.Split(stateKey, ".")
+			if len(stateKeyParts) == len(attrParts) {
+				for i := range attrParts {
+					if attrParts[i] != stateKeyParts[i] && attrParts[i] != sentinelIndex {
+						break
+					}
+					if i == len(attrParts)-1 {
+						return nil
 					}
 				}
 			}
 		}
-
-		return fmt.Errorf("%q no TypeSet element %q, with value %q in state: %#v", res, attr, value, is.Attributes)
 	}
+
+	return fmt.Errorf("no TypeSet element %q, with value %q in state: %#v", attr, value, is.Attributes)
 }