fix icrc7

README.md

@@ -310,16 +310,16 @@ However, due to the way the Swift Decoding System works, we can not do the same
 
   ```swift
   enum NamedVariant {
-      case one(Int8)
-      case two(Int16)
-      case three(a: Int8, b: Int16)
+    case one(Int8)
+    case two(Int16)
+    case three(a: Int8, b: Int16)
 
-      enum CodingKeys: String, CandidCodingKey {
-          case one, two, three
-      }
-      enum ThreeCodingKeys: String, CandidCodingKey {
-          case a, b
-      }
+    enum CodingKeys: String, CandidCodingKey {
+      case one, two, three
+    }
+    enum ThreeCodingKeys: String, CandidCodingKey {
+      case a, b
+    }
   }
   ```
 
@@ -333,16 +333,16 @@ However, due to the way the Swift Decoding System works, we can not do the same
 
   ```swift
   enum UnnamedVariant {
-      case anyName(Int8)
-      case really(Int16)
-      case weCanChoose(here: Int8, too: Int16)
+    case anyName(Int8)
+    case really(Int16)
+    case weCanChoose(here: Int8, too: Int16)
 
-      enum CodingKeys: Int, CodingKey {
-          case anyName, really, weCanChoose	// as long as we keep the order here
-      }
-      enum WeCanChooseCodingKeys: Int, CodingKey {
-          case here, too										// and here
-      }
+    enum CodingKeys: Int, CodingKey {
+      case anyName, really, weCanChoose	// as long as we keep the order here
+    }
+    enum WeCanChooseCodingKeys: Int, CodingKey {
+      case here, too										// and here
+    }
   }
   ```
 
@@ -356,11 +356,11 @@ There are several ways to perform a request. Depending if it is a simple query o
 #### Define the method you wish to call :
 ```swift
 let method = ICPMethod(
-    canister: ICPSystemCanisters.ledger,
-    methodName: "account_balance",
-    arg: .record([
-        "account": .blob(account.accountId)
-    ])
+  canister: ICPSystemCanisters.ledger,
+  methodName: "account_balance",
+  arg: .record([
+    "account": .blob(account.accountId)
+  ])
 )
 ```
 #### Make the a simple query request:
@@ -435,6 +435,19 @@ class SimpleSigningPrincipal: ICPSigningPrincipal {
   func sign(_ message: Data, domain: ICPDomainSeparator) async throws -> Data {
     return try ICPCryptography.ellipticSign(message, domain: domain, with: privateKey)
   }
+
+  static func fromMnemonic(_ words: [String]) throws -> SimplePrincipal {
+    let seed = HdWalletKit.Mnemonic.seed(mnemonic: words)!
+    let xPrivKey = HDExtendedKeyVersion.xprv.rawValue
+    let privateKey = try HDPrivateKey(seed: seed, xPrivKey: xPrivKey)
+      .derived(at: 44, hardened: true)
+      .derived(at: 223, hardened: true)
+      .derived(at: 0, hardened: true)
+      .derived(at: 0, hardened: false)
+      .derived(at: 0, hardened: false)
+    let publicKey = privateKey.publicKey(compressed: false)
+    return try SimplePrincipal(privateKey: privateKey.raw, uncompressedPublicKey: publicKey.raw)
+  }
 }
 ```
 
@@ -443,4 +456,4 @@ class SimpleSigningPrincipal: ICPSigningPrincipal {
 - Serialisation of recursive candid values leads to infinite loop.
 - Encoding of `CandidFunctionProtocol` is not supported as there is no easy way to infer the `CandidTypes` used in the arguments and results of the function. This means that the automatic code generation will fail when calling a canister method that expects another function as input.
 - Encoding of `CandidServiceProtocol` is not supported because functions can not be encoded. 
-- Encoding of chained optionals loses the type after one optionality level.
+- Encoding of optional `Structs` can not infer the members of the struct. These are encoded as `opt empty` which should be accepted by all canisters according to Candid specifications.

Sources/Candid/Encoding/CandidDecoder.swift

@@ -125,9 +125,7 @@ private class CandidSingleValueDecodingContainer: SingleValueDecodingContainer {
     }
 
     func decode<T>(_ type: T.Type) throws -> T where T: Decodable {
-        guard let childValue = input.optionValue?.value else {
-            throw DecodingError.typeMismatch(T.self, .init(codingPath: codingPath, debugDescription: "not an optional"))
-        }
+        let childValue = input.optionValue?.value ?? input
         let decoder = CandidValueDecoder(childValue, codingPath + [IntCodingKey(intValue: 0)])
         return try decoder.candidDecode()
     }

Sources/IcpKit/ICPRequest/ICPService.swift

@@ -11,8 +11,12 @@ open class ICPService {
     public let canister: ICPPrincipal
     public let client: ICPRequestClient
 
-    public init(canister: ICPPrincipal, client: ICPRequestClient) {
+    public init(canister: ICPPrincipal, client: ICPRequestClient = ICPRequestClient()) {
         self.canister = canister
         self.client = client
     }
+
+    public convenience init(_ canister: String, client: ICPRequestClient = ICPRequestClient()) throws {
+        self.init(canister: try ICPPrincipal(canister), client: client)
+    }
 }

Tests/CodeGeneratorTests/CodeGeneratorTests.swift

@@ -166,6 +166,24 @@ let cValue: UnnamedType0 = .c(bool: true, int8: 7)
             XCTAssertEqual(generated, expected)
         }
     }
+
+    func testIcrc7() async throws {
+        // GoldNFT
+        let service = try ICRC7.Service("io7gn-vyaaa-aaaak-qcbiq-cai")
+        let collectionMetadata = try await service.icrc7_collection_metadata()
+        let tokens = try await service.icrc7_tokens(prev: nil, take: nil)
+        for metadata in collectionMetadata {
+            print(metadata.tuple)
+        }
+        let token = tokens.first!
+        print(token)
+        let tokenMetadata = try await service.icrc7_token_metadata(token_ids: [token]).first!._1!
+        guard case .Text(let text) = tokenMetadata._1 else {
+            XCTFail()
+            return
+        }
+        print(text)
+    }
 }
 
 private class BundleDidProvider: CandidInterfaceDefinitionProvider {

Tests/CodeGeneratorTests/DidFiles/ICRC7.did

@@ -55,7 +55,7 @@ service : {
   icrc7_tx_window : () -> (opt nat) query;
   icrc7_permitted_drift : () -> (opt nat) query;
   icrc7_token_metadata : (token_ids : vec nat)
-      -> (vec opt vec record { text; Value }) query;
+      -> (vec record { nat; opt record { text; Value } }) query;
   icrc7_owner_of : (token_ids : vec nat)
       -> (vec opt Account) query;
   icrc7_balance_of : (vec Account) -> (vec nat) query;

Tests/CodeGeneratorTests/Generated/ICRC7.did.generated_swift

@@ -139,7 +139,7 @@ enum ICRC7 {
 	///   icrc7_tx_window : () -> (opt nat) query;
 	///   icrc7_permitted_drift : () -> (opt nat) query;
 	///   icrc7_token_metadata : (token_ids : vec nat)
-	///       -> (vec opt vec record { text; Value }) query;
+	///       -> (vec record { nat; opt record { text; Value } }) query;
 	///   icrc7_owner_of : (token_ids : vec nat)
 	///       -> (vec opt Account) query;
 	///   icrc7_balance_of : (vec Account) -> (vec nat) query;
@@ -256,9 +256,9 @@ enum ICRC7 {
 		}
 
 		/// icrc7_token_metadata : (token_ids : vec nat)
-		///       -> (vec opt vec record { text; Value }) query;
-		func icrc7_token_metadata(token_ids: [BigUInt], sender: ICPSigningPrincipal? = nil) async throws -> [[CandidTuple2<String, Value>]?] {
-			let caller = ICPQuery<[BigUInt], [[CandidTuple2<String, Value>]?]>(canister, "icrc7_token_metadata")
+		///       -> (vec record { nat; opt record { text; Value } }) query;
+		func icrc7_token_metadata(token_ids: [BigUInt], sender: ICPSigningPrincipal? = nil) async throws -> [CandidTuple2<BigUInt, CandidTuple2<String, Value>?>] {
+			let caller = ICPQuery<[BigUInt], [CandidTuple2<BigUInt, CandidTuple2<String, Value>?>]>(canister, "icrc7_token_metadata")
 			let response = try await caller.callMethod(token_ids, client, sender: sender)
 			return response
 		}

Tests/CodeGeneratorTests/Generated/ICRC7.did.swift

@@ -139,7 +139,7 @@ enum ICRC7 {
 	///   icrc7_tx_window : () -> (opt nat) query;
 	///   icrc7_permitted_drift : () -> (opt nat) query;
 	///   icrc7_token_metadata : (token_ids : vec nat)
-	///       -> (vec opt vec record { text; Value }) query;
+	///       -> (vec record { nat; opt record { text; Value } }) query;
 	///   icrc7_owner_of : (token_ids : vec nat)
 	///       -> (vec opt Account) query;
 	///   icrc7_balance_of : (vec Account) -> (vec nat) query;
@@ -256,9 +256,9 @@ enum ICRC7 {
 		}
 
 		/// icrc7_token_metadata : (token_ids : vec nat)
-		///       -> (vec opt vec record { text; Value }) query;
-		func icrc7_token_metadata(token_ids: [BigUInt], sender: ICPSigningPrincipal? = nil) async throws -> [[CandidTuple2<String, Value>]?] {
-			let caller = ICPQuery<[BigUInt], [[CandidTuple2<String, Value>]?]>(canister, "icrc7_token_metadata")
+		///       -> (vec record { nat; opt record { text; Value } }) query;
+		func icrc7_token_metadata(token_ids: [BigUInt], sender: ICPSigningPrincipal? = nil) async throws -> [CandidTuple2<BigUInt, CandidTuple2<String, Value>?>] {
+			let caller = ICPQuery<[BigUInt], [CandidTuple2<BigUInt, CandidTuple2<String, Value>?>]>(canister, "icrc7_token_metadata")
 			let response = try await caller.callMethod(token_ids, client, sender: sender)
 			return response
 		}