chore: refactor download tests

Sources/BinaryDependencyManager/DepeneciesResolverRunner.swift

@@ -91,7 +91,7 @@ public struct DependenciesResolverRunner {
         let checksum = try runThrowable("Calculating checksum") { try calculateChecksum(fileURL: downloadFileURL) }
 
         guard checksum == asset.checksum else {
-            throw NSError(domain: "Checksum is incorrect. \(checksum) != \(asset.checksum)", code: 0)
+            throw GenericError("Checksum is incorrect. \(checksum) != \(asset.checksum)")
         }
     }
 
@@ -184,7 +184,7 @@ public struct DependenciesResolverRunner {
         downloadsDirectoryURL
             .appending(components: dependency.repo, dependency.tag, asset.outputDirectory ?? "", directoryHint: .isDirectory)
     }
-
+    
     /// Location of the file where the downloaded dependency will be placed
     func downloadURL(for dependency: Dependency, asset: Dependency.Asset) -> URL {
         downloadDirectoryURL(for: dependency, asset: asset)

Sources/Utils/GenericError.swift

@@ -1,7 +1,7 @@
 
 /// An error type that is presented to the user as an error with parsing their
 /// command-line input.
-public struct GenericError: Error, CustomStringConvertible {
+public struct GenericError: Error, CustomStringConvertible, Equatable {
   /// The error message represented by this instance, this string is presented to
   /// the user when a `ValidationError` is thrown from either; `run()`,
   /// `validate()` or a transform closure.

Tests/BinaryDependencyManagerTests/DependenciesResolverRunner/DependenciesResolverRunnerDownloadTests.swift

@@ -4,33 +4,34 @@ import Foundation
 import Utils
 
 @Suite("DependenciesResolverRunner Download Method Tests")
-struct DependenciesResolverRunnerDownloadTests {
-    let sampleDependency: Dependency = Dependency(
+class DependenciesResolverRunnerDownloadTests {
+    let sampleAsset = Dependency.Asset(
+        checksum: "abc123",
+        pattern: "asset.zip",
+        contents: nil,
+        outputDirectory: nil
+    )
+
+    lazy var sampleDependency: Dependency = Dependency(
         repo: "org/repo",
         tag: "1.0.0",
         assets: [
-            Dependency.Asset(
-                checksum: "abc123",
-                pattern: "asset.zip",
-                contents: nil,
-                outputDirectory: nil
-            )
+            sampleAsset,
         ]
     )
-
+
+    lazy var fileManager = FileManagerProtocolMock(tempDir: tempDir)
+    let downloaderMock = BinaryDependenciesDownloaderMock()
+    let checksumCalculatorMock = ChecksumCalculatorProtocolMock()
+
     let tempDir: URL = {
         FileManager.default.temporaryDirectory
             .appending(components: "binary-dependency-manager-tests", UUID().uuidString, directoryHint: .isDirectory)
     }()
 
-    func makeRunner(
-        fileManager: FileManagerProtocolMock = FileManagerProtocolMock(),
-        dependencies: [Dependency]? = nil,
-        downloaderMock: BinaryDependenciesDownloaderMock = BinaryDependenciesDownloaderMock(),
-        checksumCalculatorMock: ChecksumCalculatorProtocolMock = ChecksumCalculatorProtocolMock()
-    ) -> DependenciesResolverRunner {
+    func makeRunner() -> DependenciesResolverRunner {
         DependenciesResolverRunner.mock(
-            dependencies: dependencies ?? [sampleDependency],
+            dependencies: [sampleDependency],
             outputDirectoryURL: tempDir.appending(path: "output", directoryHint: .isDirectory),
             cacheDirectoryURL: tempDir.appending(path: "cache", directoryHint: .isDirectory),
             fileManager: fileManager,
@@ -43,15 +44,8 @@ struct DependenciesResolverRunnerDownloadTests {
     @Test("download creates directory and downloads file when not already downloaded")
     func download_success() async throws {
         // GIVEN
-        let fileManager = FileManagerProtocolMock(tempDir: tempDir)
-        let downloaderMock = BinaryDependenciesDownloaderMock()
-        let checksumCalculatorMock = ChecksumCalculatorProtocolMock()
-        let runner = makeRunner(
-            fileManager: fileManager,
-            downloaderMock: downloaderMock,
-            checksumCalculatorMock: checksumCalculatorMock
-        )
-        let sampleAsset = sampleDependency.assets[0]
+
+        let runner = makeRunner()
         let downloadURL = runner.downloadURL(for: sampleDependency, asset: sampleAsset)
 
         // Set up checksum calculation to return the expected checksum
@@ -80,15 +74,7 @@ struct DependenciesResolverRunnerDownloadTests {
     @Test("download skips download when file already exists with correct checksum")
     func download_skipsWhenAlreadyDownloaded() async throws {
         // GIVEN
-        let fileManager = FileManagerProtocolMock(tempDir: tempDir)
-        let downloaderMock = BinaryDependenciesDownloaderMock()
-        let checksumCalculatorMock = ChecksumCalculatorProtocolMock()
-        let runner = makeRunner(
-            fileManager: fileManager,
-            downloaderMock: downloaderMock,
-            checksumCalculatorMock: checksumCalculatorMock
-        )
-        let sampleAsset = sampleDependency.assets[0]
+        let runner = makeRunner()
         let downloadURL = runner.downloadURL(for: sampleDependency, asset: sampleAsset)
 
         // File already exists
@@ -107,100 +93,43 @@ struct DependenciesResolverRunnerDownloadTests {
     @Test("download throws error when checksums don't match")
     func download_throwsErrorOnChecksumMismatch() async throws {
         // GIVEN
-        let fileManager = FileManagerProtocolMock(tempDir: tempDir)
-        let downloaderMock = BinaryDependenciesDownloaderMock()
-        let checksumCalculatorMock = ChecksumCalculatorProtocolMock()
-        let runner = makeRunner(
-            fileManager: fileManager,
-            downloaderMock: downloaderMock,
-            checksumCalculatorMock: checksumCalculatorMock
-        )
-        let sampleAsset = sampleDependency.assets[0]
+        let runner = makeRunner()
         let downloadURL = runner.downloadURL(for: sampleDependency, asset: sampleAsset)
 
         // Set up checksum calculation to return wrong checksum
-        checksumCalculatorMock.checksums[downloadURL] = "wrong_checksum"
-
+        let wrongChecksum = "wrong_checksum"
+        checksumCalculatorMock.checksums[downloadURL] = wrongChecksum
+
         // WHEN & THEN
-        #expect(throws: Error.self) {
+        // runner must throw
+        let error = try #require(throws: GenericError.self) {
             try runner.download(sampleDependency, asset: sampleAsset, with: downloaderMock)
         }
-
-        // Verify downloader was called
-        #expect(downloaderMock.downloadReleaseAssetCalls.count == 1)
-    }
-
-    @Test("download redownloads when existing file has wrong checksum")
-    func download_redownloadsOnChecksumMismatch() async throws {
-        // GIVEN
-        let fileManager = FileManagerProtocolMock(tempDir: tempDir)
-        let downloaderMock = BinaryDependenciesDownloaderMock()
-        let checksumCalculatorMock = ChecksumCalculatorProtocolMock()
-        let runner = makeRunner(
-            fileManager: fileManager,
-            downloaderMock: downloaderMock,
-            checksumCalculatorMock: checksumCalculatorMock
+        #expect(
+            error.message.contains("Checksum is incorrect. \(wrongChecksum) != \(sampleAsset.checksum)"),
+            "Thrown error describes invalid checksum"
         )
-        let sampleAsset = sampleDependency.assets[0]
-        let downloadURL = runner.downloadURL(for: sampleDependency, asset: sampleAsset)
-
-        // File already exists
-        fileManager.existingFiles.insert(downloadURL.path(percentEncoded: false))
-        // First checksum call returns wrong checksum, second returns correct
-        checksumCalculatorMock.checksums[downloadURL] = "wrong_checksum"
-
-        // WHEN & THEN
-        #expect(throws: Error.self) {
-            try runner.download(sampleDependency, asset: sampleAsset, with: downloaderMock)
-        }
-
-        // Verify file was removed due to checksum mismatch
-        #expect(fileManager.removedItems.contains(downloadURL))
-
-        // Verify downloader was called
-        #expect(downloaderMock.downloadReleaseAssetCalls.count == 1)
+
+        // Verify check sum calc was called
+        #expect(checksumCalculatorMock.checksumCalls.count == 1)
     }
-    
+
     @Test("download propagates downloader errors")
     func download_propagatesDownloaderErrors() async throws {
         // GIVEN
-        let fileManager = FileManagerProtocolMock(tempDir: tempDir)
-        let downloaderMock = BinaryDependenciesDownloaderMock(throwError: GenericError("Download failed"))
-        let checksumCalculatorMock = ChecksumCalculatorProtocolMock()
-        let runner = makeRunner(
-            fileManager: fileManager,
-            downloaderMock: downloaderMock,
-            checksumCalculatorMock: checksumCalculatorMock
-        )
-        let sampleAsset = sampleDependency.assets[0]
-
-        // WHEN & THEN
-        #expect(throws: Error.self) {
-            try runner.download(sampleDependency, asset: sampleAsset, with: downloaderMock)
-        }
-
-        // Verify downloader was called
-        #expect(downloaderMock.downloadReleaseAssetCalls.count == 1)
-    }
-
-    @Test("download propagates checksum calculation errors")
-    func download_propagatesChecksumErrors() async throws {
-        // GIVEN
-        let fileManager = FileManagerProtocolMock(tempDir: tempDir)
-        let downloaderMock = BinaryDependenciesDownloaderMock()
-        let checksumCalculatorMock = ChecksumCalculatorProtocolMock(errorToThrow: GenericError("Checksum calculation failed"))
-        let runner = makeRunner(
-            fileManager: fileManager,
-            downloaderMock: downloaderMock,
-            checksumCalculatorMock: checksumCalculatorMock
-        )
-        let sampleAsset = sampleDependency.assets[0]
-
+        // Downloader throws error
+        let downloadError = GenericError("Download failed")
+        downloaderMock.throwError = downloadError
+
+        let runner = makeRunner()
+
         // WHEN & THEN
-        #expect(throws: Error.self) {
+        // runner must throw
+        let error = try #require(throws: GenericError.self) {
             try runner.download(sampleDependency, asset: sampleAsset, with: downloaderMock)
         }
-
+        #expect(error == downloadError, "thrown error by runner equals to the error thrown by downloader")
+
         // Verify downloader was called
         #expect(downloaderMock.downloadReleaseAssetCalls.count == 1)
     }