Streamable functions - Change "stream()" signature.

FirebaseFunctions/Sources/Callable+Codable.swift

@@ -160,9 +160,10 @@ public struct Callable<Request: Encodable, Response: Decodable> {
     return try await call(data)
   }
 
+public extension Callable {
   // TODO: Look into handling parameter-less functions.
   @available(macOS 12.0, iOS 15.0, watchOS 8.0, tvOS 15.0, *)
-  public func stream(_ data: Request) -> AsyncThrowingStream<Response, Error> {
+  public func stream(_ data: Request? = nil) -> AsyncThrowingStream<Response, Error> {
     return AsyncThrowingStream { continuation in
       Task {
         do {

FirebaseFunctions/Tests/Integration/IntegrationTests.swift

@@ -985,7 +985,7 @@ class IntegrationTests: XCTestCase {
       )
 
       let result = try await response(from: stream)
-      // Since we are sending a bad URL we expect an empty array, the reuqets was not a 200.
+      // Since we are sending a bad URL we expect an empty array, the request was not a 200.
       XCTAssertEqual(
         result,
         []
@@ -1007,10 +1007,37 @@ class IntegrationTests: XCTestCase {
       )
 
       let result = try await response(from: stream)
-      XCTFail("TODO: FETCH THE ERROR")
+     XCTFail("TODO: FETCH THE ERROR")
     }
   }
 
+  @available(iOS 15.0, *)
+  func testGenStreamContent() async throws {
+      let callable: Callable<String, StreamResponse<String, String>> = functions.httpsCallable("genStream")
+      let stream =  callable.stream("genStream")
+      //Todo fetch actual content.
+      for try await response in stream {
+        switch response {
+          case .message(let message):
+              print("Message: \(message)")
+          case .result(let result):
+              print("Result: \(result)")
+          }
+      }
+  }
+
+  @available(iOS 15.0, *)
+  func testGenStream_NoArgs_ThrowsError() async throws {
+      let callable: Callable<String, StreamResponse<String, String>> = functions.httpsCallable("genStream")
+      let stream =  callable.stream("")
+      //Todo fetch actual content.
+      for try await response in stream {
+       //TODO add logic to fetch the error after we enable 
+        // throw(NSError(domain: "The response cannot be decoded to the given type.", code: 0, userInfo: nil))
+        // back in Callable+Codable func stream(_ data: Request?=nil) -> AsyncThrowingStream<Response, Error>
+      }
+  }
+
   private func response(from stream: AsyncThrowingStream<HTTPSCallableResult,
     any Error>) async throws -> [String] {
     var response = [String]()

FirebaseFunctions/Tests/Unit/FunctionsTests.swift

@@ -371,6 +371,7 @@ class FunctionsTests: XCTestCase {
   @available(iOS 15, *)
   func testGenerateStreamContentCanceled() async {
     XCTFail("TODO")
+    //Implent full tests when stremable<> is ready.
   }
 
   @available(iOS 15, *)