[Functions] Include endpoint and region details in error messages

FirebaseFunctions/Sources/Functions.swift

@@ -401,9 +401,9 @@ enum FunctionsConstants {
 
     do {
       let rawData = try await fetcher.beginFetch()
-      return try callableResult(fromResponseData: rawData)
+      return try callableResult(fromResponseData: rawData, endpointURL: url)
     } catch {
-      throw processedError(fromResponseError: error)
+      throw processedError(fromResponseError: error, endpointURL: url)
     }
   }
 
@@ -454,10 +454,10 @@ enum FunctionsConstants {
     fetcher.beginFetch { [self] data, error in
       let result: Result<HTTPSCallableResult, any Error>
       if let error {
-        result = .failure(processedError(fromResponseError: error))
+        result = .failure(processedError(fromResponseError: error, endpointURL: url))
       } else if let data {
         do {
-          result = try .success(callableResult(fromResponseData: data))
+          result = try .success(callableResult(fromResponseData: data, endpointURL: url))
         } catch {
           result = .failure(error)
         }
@@ -523,11 +523,14 @@ enum FunctionsConstants {
     return fetcher
   }
 
-  private func processedError(fromResponseError error: any Error) -> any Error {
+  private func processedError(fromResponseError error: any Error,
+                              endpointURL url: URL) -> any Error {
     let error = error as NSError
     let localError: (any Error)? = if error.domain == kGTMSessionFetcherStatusDomain {
       FunctionsError(
         httpStatusCode: error.code,
+        region: region,
+        url: url,
         body: error.userInfo["data"] as? Data,
         serializer: serializer
       )
@@ -538,18 +541,25 @@ enum FunctionsConstants {
     return localError ?? error
   }
 
-  private func callableResult(fromResponseData data: Data) throws -> HTTPSCallableResult {
-    let processedData = try processedData(fromResponseData: data)
+  private func callableResult(fromResponseData data: Data,
+                              endpointURL url: URL) throws -> HTTPSCallableResult {
+    let processedData = try processedData(fromResponseData: data, endpointURL: url)
     let json = try responseDataJSON(from: processedData)
     // TODO: Refactor `decode(_:)` so it either returns a non-optional object or throws
     let payload = try serializer.decode(json)
     // TODO: Remove `as Any` once `decode(_:)` is refactored
     return HTTPSCallableResult(data: payload as Any)
   }
 
-  private func processedData(fromResponseData data: Data) throws -> Data {
+  private func processedData(fromResponseData data: Data, endpointURL url: URL) throws -> Data {
     // `data` might specify a custom error. If so, throw the error.
-    if let bodyError = FunctionsError(httpStatusCode: 200, body: data, serializer: serializer) {
+    if let bodyError = FunctionsError(
+      httpStatusCode: 200,
+      region: region,
+      url: url,
+      body: data,
+      serializer: serializer
+    ) {
       throw bodyError
     }
 

FirebaseFunctions/Sources/FunctionsError.swift

@@ -180,7 +180,8 @@ struct FunctionsError: CustomNSError {
   ///     }
   ///     ```
   ///   - serializer: The `FunctionsSerializer` used to decode `details` in the error body.
-  init?(httpStatusCode: Int, body: Data?, serializer: FunctionsSerializer) {
+  init?(httpStatusCode: Int, region: String, url: URL, body: Data?,
+        serializer: FunctionsSerializer) {
     // Start with reasonable defaults from the status code.
     var code = FunctionsErrorCode(httpStatusCode: httpStatusCode)
     var description = Self.errorDescription(from: code)
@@ -224,6 +225,8 @@ struct FunctionsError: CustomNSError {
 
     var userInfo = [String: Any]()
     userInfo[NSLocalizedDescriptionKey] = description
+    userInfo["region"] = region
+    userInfo["url"] = url
     if let details {
       userInfo[FunctionsErrorDetailsKey] = details
     }

FirebaseFunctions/Tests/Unit/FunctionsErrorTests.swift

@@ -45,6 +45,8 @@ final class FunctionsErrorTests: XCTestCase {
     // The error should be `nil`.
     let error = FunctionsError(
       httpStatusCode: 200,
+      region: "my-region",
+      url: URL(string: "https://example.com/fake_func")!,
       body: nil,
       serializer: FunctionsSerializer()
     )
@@ -56,6 +58,8 @@ final class FunctionsErrorTests: XCTestCase {
     // The error should be inferred from the HTTP status code.
     let error = FunctionsError(
       httpStatusCode: 429,
+      region: "my-region",
+      url: URL(string: "https://example.com/fake_func")!,
       body: nil,
       serializer: FunctionsSerializer()
     )
@@ -66,7 +70,7 @@ final class FunctionsErrorTests: XCTestCase {
     XCTAssertEqual(nsError.domain, "com.firebase.functions")
     XCTAssertEqual(nsError.code, 8)
     XCTAssertEqual(nsError.localizedDescription, "RESOURCE EXHAUSTED")
-    XCTAssertEqual(nsError.userInfo.count, 1)
+    XCTAssertEqual(nsError.userInfo.count, 3)
   }
 
   func testInitWithOKStatusCodeAndIncompleteErrorBody() {
@@ -75,6 +79,8 @@ final class FunctionsErrorTests: XCTestCase {
 
     let error = FunctionsError(
       httpStatusCode: 200,
+      region: "my-region",
+      url: URL(string: "https://example.com/fake_func")!,
       body: responseData,
       serializer: FunctionsSerializer()
     )
@@ -85,7 +91,7 @@ final class FunctionsErrorTests: XCTestCase {
     XCTAssertEqual(nsError.domain, "com.firebase.functions")
     XCTAssertEqual(nsError.code, 11)
     XCTAssertEqual(nsError.localizedDescription, "OUT OF RANGE")
-    XCTAssertEqual(nsError.userInfo.count, 1)
+    XCTAssertEqual(nsError.userInfo.count, 3)
   }
 
   func testInitWithErrorStatusCodeAndErrorBody() {
@@ -96,6 +102,8 @@ final class FunctionsErrorTests: XCTestCase {
 
     let error = FunctionsError(
       httpStatusCode: 499,
+      region: "my-region",
+      url: URL(string: "https://example.com/fake_func")!,
       body: responseData,
       serializer: FunctionsSerializer()
     )
@@ -106,7 +114,7 @@ final class FunctionsErrorTests: XCTestCase {
     XCTAssertEqual(nsError.domain, "com.firebase.functions")
     XCTAssertEqual(nsError.code, 11)
     XCTAssertEqual(nsError.localizedDescription, "TEST_ErrorMessage")
-    XCTAssertEqual(nsError.userInfo.count, 2)
+    XCTAssertEqual(nsError.userInfo.count, 4)
     XCTAssertEqual(nsError.userInfo["details"] as? Int, 123)
   }
 
@@ -119,6 +127,8 @@ final class FunctionsErrorTests: XCTestCase {
 
     let error = FunctionsError(
       httpStatusCode: 401,
+      region: "my-region",
+      url: URL(string: "https://example.com/fake_func")!,
       body: responseData,
       serializer: FunctionsSerializer()
     )
@@ -133,6 +143,8 @@ final class FunctionsErrorTests: XCTestCase {
 
     let error = FunctionsError(
       httpStatusCode: 403,
+      region: "my-region",
+      url: URL(string: "https://example.com/fake_func")!,
       body: responseData,
       serializer: FunctionsSerializer()
     )
@@ -143,7 +155,7 @@ final class FunctionsErrorTests: XCTestCase {
     XCTAssertEqual(nsError.domain, "com.firebase.functions")
     XCTAssertEqual(nsError.code, 7) // `permissionDenied`, inferred from the HTTP status code
     XCTAssertEqual(nsError.localizedDescription, "TEST_ErrorMessage")
-    XCTAssertEqual(nsError.userInfo.count, 2)
+    XCTAssertEqual(nsError.userInfo.count, 4)
     XCTAssertEqual(nsError.userInfo["details"] as? NSNull, NSNull())
   }
 
@@ -155,6 +167,8 @@ final class FunctionsErrorTests: XCTestCase {
 
     let error = FunctionsError(
       httpStatusCode: 503,
+      region: "my-region",
+      url: URL(string: "https://example.com/fake_func")!,
       body: responseData,
       serializer: FunctionsSerializer()
     )