Create a set of tests that check that functionality is maintained

when a `CheckpointSource` is used instead of Checkpoint helpers

Tests/OfflineTests/CheckpointSourceTests.swift

@@ -4,32 +4,129 @@
 //
 //  Created by Francisco Gindre on 10/30/23.
 //
-
 import XCTest
+@testable import TestUtils
+@testable import ZcashLightClientKit
 
-final class CheckpointSourceTests: XCTestCase {
+class CheckpointSourceTests: XCTestCase {
+    func test_BirthdayGetsMostRecentCheckpointBelowIt_Testnet() throws {
 
-    override func setUpWithError() throws {
-        // Put setup code here. This method is called before the invocation of each test method in the class.
+        let source = CheckpointSourceFactory.fromBundle(for: .testnet)
+
+        let birthday = source.birthday(for: 1530003)
+
+        let expected = Checkpoint(
+            height: 1530000,
+            hash: "0011f78082f26747e02f0ab3525dc34d8df8f69dde273f462fcbf08fe2aa14d6",
+            time: 1629030383,
+            saplingTree: """
+            0103ac57cbe96a0f86b78527aa69b21db02318e7e7a6995cbe497a107707825655001001623311941fc8cfac849331dca1ba89a60552eb9dbadd0019f8dfcb5f6ac6c906\
+            01b9a73d583be12b8e9c8a7616fe78a65469a2b91bdf02d411951fa261c9e1e64001e64e2365c8064f711643681da68b4fd626b28e5624abb9fb19d13208818b4d600133\
+            0c2415a69eddb56d7a0846f03f4c98936607d5c0e7f580748224bd2117e51200000149f61a12a3f8407f4f7bd3e4f619937fa1a09e984a5f7334fcd7734c4ba3e3690000\
+            0001bab80e68a5c63460d1e5c94ef540940792fa4703fa488b09fdfded97f8ec8a3d00013d2fd009bf8a22d68f720eac19c411c99014ed9c5f85d5942e15d1fc039e2868\
+            0001f08f39275112dd8905b854170b7f247cf2df18454d4fa94e6e4f9320cca05f24011f8322ef806eb2430dc4a7a41c1b344bea5be946efc7b4349c1c9edb14ff9d39
+            """,
+            orchardTree: nil
+        )
+
+        XCTAssertEqual(birthday, expected)
     }
 
-    override func tearDownWithError() throws {
-        // Put teardown code here. This method is called after the invocation of each test method in the class.
+    func test_BirthdayGetsMostRecentCheckpointBelowIt_Mainnet() throws {
+        let source = CheckpointSourceFactory.fromBundle(for: .mainnet)
+
+        let birthday = source.birthday(for: 1340004)
+
+        let expected = Checkpoint(
+            height: 1340000,
+            hash: "00000000031bc547da975ebd77d9113b178053f88fb6a1d8511b4f8962c21c4b",
+            time: 1627846248,
+            saplingTree: """
+            01ef55e131bf5e7d6737a6e353fe0ff246ba8938a264335457452db2c4023241590113f4e2a1f043d0a303c769d9aac5eeb8b6854d1a64d71b6b86cda2e0eeee07621301\
+            206a8d77952d4143cc5ba4d7943261e7145f0f138a81fe37c10e50a487487966012fb54cf3a70cccf01479fefc42e539c92a8215aead4179278cf1e8a302cb4868014574\
+            313eb9fd9ee592346fdf27752f698c1f629b044437853972e266e95b56020001be3f0fa5b20bbfa445293d588073dc27a856c92e9903831c6de4455f03d57a0401bb534b\
+            0af17c990f836204115aa17d4c2504fa0a675353ec7ae8a7d67510cc46012e2edeb7e5acb0d440dd5b500bec4a6efd6f53ba02c10e3883e23e53d7f91369000183c334e4\
+            55aeeeb82cceddbe832919324d7011418749fc9dea759cfa6c2cc21501f4a3504117d35efa15f57d5fdd19515b7fb1dd14c3b98b8a91685f0f788db330000000018846ec\
+            9170ad4e40a093cfb53162e5211d55377d8d22f826cde7783d30c1dd5f01b35fe4a943a47404f68db220c77b0573e13c3378a65c6f2396f93be7609d8f2a000125911f45\
+            24469c00ccb1ba69e64f0ee7380c8d17bbfc76ecd238421b86eb6e09000118f64df255c9c43db708255e7bf6bffd481e5c2f38fe9ed8f3d189f7f9cf2644
+            """,
+            orchardTree: nil
+        )
+
+        XCTAssertEqual(birthday, expected)
     }
 
-    func testExample() throws {
-        // This is an example of a functional test case.
-        // Use XCTAssert and related functions to verify your tests produce the correct results.
-        // Any test you write for XCTest can be annotated as throws and async.
-        // Mark your test throws to produce an unexpected failure when your test encounters an uncaught error.
-        // Mark your test async to allow awaiting for asynchronous code to complete. Check the results with assertions afterwards.
+    func test_startBirthdayIsGivenIfTooLow_Testnet() throws {
+        let source = CheckpointSourceFactory.fromBundle(for: .testnet)
+
+        let birthday = source.birthday(for: 4)
+
+        let expected = Checkpoint(
+            height: 280000,
+            hash: "000420e7fcc3a49d729479fb0b560dd7b8617b178a08e9e389620a9d1dd6361a",
+            time: 1535262293,
+            saplingTree: "000000",
+            orchardTree: nil
+        )
+
+        XCTAssertEqual(birthday, expected)
     }
 
-    func testPerformanceExample() throws {
-        // This is an example of a performance test case.
-        self.measure {
-            // Put the code you want to measure the time of here.
-        }
+    func test_startBirthdayIsGivenIfTooLow_Mainnet() throws {
+        let source = CheckpointSourceFactory.fromBundle(for: .mainnet)
+
+        let birthday = source.birthday(for: 4)
+
+        let expected = Checkpoint(
+            height: 419200,
+            hash: "00000000025a57200d898ac7f21e26bf29028bbe96ec46e05b2c17cc9db9e4f3",
+            time: 1540779337,
+            saplingTree: "000000",
+            orchardTree: nil
+        )
+
+        XCTAssertEqual(birthday, expected)
     }
 
+    func test_orchardTreeIsNotNilOnActivation_Mainnet() throws {
+        let activationHeight = 1_687_104
+
+        let source = CheckpointSourceFactory.fromBundle(for: .mainnet)
+
+        let birthday = source.birthday(for: 4)
+
+        XCTAssertEqual(birthday.height, activationHeight)
+        XCTAssertEqual(birthday.orchardTree, "000000")
+    }
+
+    func test_orchardTreeIsNilBeforeActivation_Mainnet() throws {
+        let activationHeight = 1_687_104
+
+        let source = CheckpointSourceFactory.fromBundle(for: .mainnet)
+
+        let birthday = source.birthday(for: activationHeight - 1)
+
+        XCTAssertNil(birthday.orchardTree)
+    }
+
+    func test_orchardTreeIsNotNilOnActivation_Testnet() throws {
+        let activationHeight = 1_842_420
+
+        let source = CheckpointSourceFactory.fromBundle(for: .testnet)
+
+        let birthday = source.birthday(for: activationHeight)
+
+        XCTAssertEqual(birthday.height, activationHeight)
+        XCTAssertEqual(birthday.orchardTree, "000000")
+    }
+
+    func test_orchardTreeIsNilBeforeActivation_Testnet() throws {
+        let activationHeight = 1_687_104
+
+        let source = CheckpointSourceFactory.fromBundle(for: .testnet)
+
+        let birthday = source.birthday(for: activationHeight - 1)
+
+        XCTAssertNil(birthday.orchardTree)
+    }
 }