fix: schema download optional (#116)

(cherry picked from commit 37655c1)

Author: goncalo-frade-iohk

AtalaPrismSDK/Pollux/Sources/Models/AnonCreds/AnonCredentialDefinition.swift

@@ -14,7 +14,7 @@ struct AnonCredentialDefinition: Codable {
         let z: String
     }
 
-    let issuerId: String
+    let issuerId: String?
     let schemaId: String
     let type: String
     let tag: String

AtalaPrismSDK/Pollux/Sources/Models/AnonCreds/AnonCredentialSchema.swift

@@ -3,7 +3,7 @@ import Foundation
 struct AnonCredentialSchema: Codable {
     let name: String
     let version: String
-    let attrNames: [String]
+    let attrNames: [String]?
     let issuerId: String
 }
 

AtalaPrismSDK/Pollux/Sources/Models/AnonCreds/AnoncredsCredentialStack.swift

@@ -3,7 +3,7 @@ import Domain
 import Foundation
 
 struct AnoncredsCredentialStack: Codable {
-    let schema: AnonCredentialSchema
+    let schema: AnonCredentialSchema?
     let definition: AnonCredentialDefinition
     let credential: AnonCredential
 }
@@ -20,7 +20,7 @@ extension AnoncredsCredentialStack: Domain.Credential {
     }
 
     var issuer: String {
-        definition.issuerId
+        definition.issuerId ?? ""
     }
 
     var subject: String? {

AtalaPrismSDK/Pollux/Sources/Models/AnonCreds/AnoncredsPresentation.swift

@@ -21,11 +21,15 @@ struct AnoncredsPresentation {
         )
 
         let credential = stack.credential
+
+        guard let stackSchema = stack.schema else {
+            throw PolluxError.invalidCredentialError
+        }
         let schema = Schema.init(
-            name: stack.schema.name,
-            version: stack.schema.version,
-            attrNames: AttributeNames(stack.schema.attrNames),
-            issuerId: stack.schema.issuerId
+            name: stackSchema.name,
+            version: stackSchema.version,
+            attrNames: AttributeNames(stackSchema.attrNames ?? []),
+            issuerId: stackSchema.issuerId
         )
 
         let credentialDefinition = try stack.definition.getAnoncred()

AtalaPrismSDK/Pollux/Sources/Operation/Anoncreds/ParseAnoncredsCredentialFromMessage.swift

@@ -45,7 +45,7 @@ struct ParseAnoncredsCredentialFromMessage {
         let processedCredentialJson = try processedCredential.getJson().tryData(using: .utf8)
         let finalCredential = try JSONDecoder().decode(AnonCredential.self, from: processedCredentialJson)
         return AnoncredsCredentialStack(
-            schema: try JSONDecoder.didComm().decode(AnonCredentialSchema.self, from: schemaData),
+            schema: try? JSONDecoder.didComm().decode(AnonCredentialSchema.self, from: schemaData),
             definition: try JSONDecoder.didComm().decode(AnonCredentialDefinition.self, from: credentialDefinitionData),
             credential: finalCredential
         )