feat: add extra validation for enums (#266)

Part of
#253.

Fixes several failing test cases identified in
#261,
getting us closer to being consistent with the schema.

Author: krzema12

src/jvmMain/kotlin/it/krzeminski/githubactionstyping/validation/types/Enum.kt

@@ -4,6 +4,9 @@ import it.krzeminski.githubactionstyping.parsing.ApiItem
 import it.krzeminski.githubactionstyping.validation.ItemValidationResult
 
 fun ApiItem.validateEnum(): ItemValidationResult {
+    if (this.name?.isBlank() == true) {
+        return ItemValidationResult.Invalid("Name must not be empty.")
+    }
     if (this.allowedValues == null) {
         return ItemValidationResult.Invalid("Allowed values must be specified.")
     }
@@ -19,5 +22,8 @@ fun ApiItem.validateEnum(): ItemValidationResult {
     if (this.allowedValues.isEmpty()) {
         return ItemValidationResult.Invalid("There must be at least one allowed value.")
     }
+    if (this.allowedValues.any { it.isBlank() }) {
+        return ItemValidationResult.Invalid("Allowed values must not be empty.")
+    }
     return ItemValidationResult.Valid
 }

src/jvmMain/kotlin/it/krzeminski/githubactionstyping/validation/types/List.kt

@@ -11,6 +11,9 @@ fun ApiItem.validateList(): ItemValidationResult {
     if (this.listItem == null) {
         return ItemValidationResult.Invalid("List item information must be specified.")
     }
+    if (this.listItem.name?.isBlank() == true) {
+        return ItemValidationResult.Invalid("List item type: Name must not be empty.")
+    }
     if (this.separator == null) {
         return ItemValidationResult.Invalid("Separator must be specified.")
     }