WIP: improve error messages

Author: volcanonoodle

internal/resources/cloud/resource_cloud_access_policy_rotating_token.go

@@ -229,22 +229,18 @@ func computeRotatingTokenName(d getter) (string, error) {
 func computeRotatingTokenExpiresAt(d getter) (*time.Time, error) {
 	rotateAfter, err := getRotatingTokenRotateAfter(d)
 	if err != nil {
-		return nil, fmt.Errorf("%w: error parsing 'rotate_after': %w", errComputingTokenField("expires_at"), err)
+		return nil, fmt.Errorf("error parsing 'rotate_after' while computing 'expires_at': %w", err)
 	}
 
 	postRotationLifetime, err := getRotatingTokenPostRotationLifetime(d)
 	if err != nil {
-		return nil, fmt.Errorf("%w: error parsing 'post_rotation_lifetime': %w", errComputingTokenField("expires_at"), err)
+		return nil, fmt.Errorf("error parsing 'post_rotation_lifetime' while computing 'expires_at': %w", err)
 	}
 
 	expiresAt := rotateAfter.Add(*postRotationLifetime)
 	return &expiresAt, nil
 }
 
-func errComputingTokenField(field string) error {
-	return fmt.Errorf("error computing token's %s", field)
-}
-
 type rotatingTokenNameAttributes struct {
 	namePrefix           string
 	postRotationLifetime string
@@ -258,24 +254,27 @@ func (r rotatingTokenNameAttributes) computedName() string {
 func rotatingTokenAttributesFromName(name string) (*rotatingTokenNameAttributes, error) {
 	parts := strings.Split(name, "-")
 	if len(parts) < 3 {
-		return nil, fmt.Errorf("rotating token name does not follow the expected pattern: %s", name)
+		return nil, fmt.Errorf("rotating token name does not follow the expected pattern '<name_prefix>-<rotate_after>-<post_rotation_lifetime>': %s", name)
 	}
 
 	// rotateAfter
 	rotateAfterStr := parts[len(parts)-2]
 	rotateAfter, err := strconv.ParseInt(rotateAfterStr, 10, 64)
 	if err != nil || rotateAfter <= 0 {
-		return nil, fmt.Errorf("error parsing rotate_after timestamp from rotating token name: %w", err)
+		return nil, fmt.Errorf("could not infer 'rotate_after' from rotating token name: %w", err)
 	}
 
 	// postRotationLifetime
 	postRotationLifetime := parts[len(parts)-1]
-	if _, err := time.ParseDuration(postRotationLifetime); err != nil {
-		return nil, fmt.Errorf("error parsing post_rotation_lifetime duration from rotating token name: %w", err)
+	if _, err = time.ParseDuration(postRotationLifetime); err != nil {
+		return nil, fmt.Errorf("could not infer 'post_rotation_lifetime' from rotating token name: %w", err)
 	}
 
 	// namePrefix
 	namePrefix := strings.Join(parts[:len(parts)-2], "-")
+	if namePrefix == "" {
+		return nil, errors.New("could not infer 'name_prefix' from rotating token name")
+	}
 
 	return &rotatingTokenNameAttributes{
 		namePrefix:           namePrefix,