ReceiptRefreshPolicy.retryUntilProductIsFound: default to returning…

… "invalid" receipt (#2024)

See #1945.

To make this retry mechanism less risky when eventually enabled, this
change makes the "worst case scenario" (where retrying didn't help, or
`AppleReceipt.containsActivePurchase` has issues) equivalent to
`ReceiptFetcher.onlyIfEmpty`.

_Note: this is currently not enabled in production, only in Integration Tests._

Sources/Purchasing/ReceiptFetcher.swift

@@ -151,10 +151,11 @@ private extension ReceiptFetcher {
         sleepDuration: DispatchTimeInterval
     ) async -> Data {
         var retries = 0
+        var data: Data = .init()
 
         repeat {
             retries += 1
-            let data = await self.refreshReceipt()
+            data = await self.refreshReceipt()
 
             if !data.isEmpty {
                 do {
@@ -176,7 +177,7 @@ private extension ReceiptFetcher {
             try? await Task.sleep(nanoseconds: UInt64(sleepDuration.nanoseconds))
         } while retries <= maximumRetries && !Task.isCancelled
 
-        return Data()
+        return data
     }
 
 }

Tests/UnitTests/Mocks/MockReceiptParser.swift

@@ -54,7 +54,7 @@ class MockReceiptParser: ReceiptParser {
             // This is used to mock changing receipts over time.
             return try self.stubbedParseResults[self.invokedParseCount - 1].get()
         } else {
-            return try XCTUnwrap(self.stubbedParseResults.first?.get())
+            return try XCTUnwrap(self.stubbedParseResults.first).get()
         }
     }
 

Tests/UnitTests/Purchasing/ReceiptFetcherTests.swift

@@ -190,7 +190,7 @@ final class RetryingReceiptFetcherTests: BaseReceiptFetcherTests {
         self.mock(receipt: Self.receiptWithoutPurchases)
 
         let data = await self.fetch(productIdentifier: Self.productID, retries: 0)
-        expect(data) == Data()
+        expect(data) == Self.receiptWithoutPurchases.asData
 
         expect(self.mockReceiptParser.invokedParseParametersList) == [
             Self.receiptWithoutPurchases.asData
@@ -203,7 +203,7 @@ final class RetryingReceiptFetcherTests: BaseReceiptFetcherTests {
         let invalidData = Self.receiptWithoutPurchases.asData
 
         let data = await self.fetch(productIdentifier: Self.productID, retries: 2)
-        expect(data) == Data()
+        expect(data) == invalidData
 
         expect(self.mockReceiptParser.invokedParseParametersList) == [
             invalidData,
@@ -240,6 +240,19 @@ final class RetryingReceiptFetcherTests: BaseReceiptFetcherTests {
         ]
     }
 
+    func testStopsRetryingEvenIfParsingReceiptKeepsThrowingError() async {
+        let invalidData = self.mockReceiptWithInvalidData()
+
+        let data = await self.fetch(productIdentifier: Self.productID, retries: 1)
+        expect(data) == invalidData
+
+        expect(self.mockRequestFetcher.refreshReceiptCalledCount) == 2
+        expect(self.mockReceiptParser.invokedParseParametersList) == [
+            invalidData,
+            invalidData
+        ]
+    }
+
     func testStopsRetryingIfFindsValidReceipt() async {
         self.mock(receipts: [Self.receiptWithoutPurchases, Self.validReceipt])
 
@@ -283,6 +296,18 @@ final class RetryingReceiptFetcherTests: BaseReceiptFetcherTests {
         self.mockReceiptParser.stubbedParseResults = receipts
     }
 
+    private func mockReceiptWithInvalidData() -> Data {
+        let invalidData = Data(repeating: 0, count: 10)
+
+        self.mockBundle.receiptURLResult = .receiptWithData
+        self.mockFileReader.mockedURLContents[self.mockBundle.appStoreReceiptURL!] = [invalidData]
+        self.mockReceiptParser.stubbedParseResults = [
+            .failure(ErrorUtils.missingReceiptFileError())
+        ]
+
+        return invalidData
+    }
+
     private static let productID = "com.revenuecat.test_product"
 
     private static let validReceipt = AppleReceipt(