Introduce mutant for #185

Package.swift

@@ -33,9 +33,13 @@ let package = Package(
             dependencies: ["XCRemoteCache"]
         ),
         .target(
-            name: "xclibtool",
+            name: "xclibtoolSupport",
             dependencies: ["XCRemoteCache"]
         ),
+        .target(
+            name: "xclibtool",
+            dependencies: ["XCRemoteCache", "xclibtoolSupport"]
+        ),
         .target(
             name: "xcpostbuild",
             dependencies: ["XCRemoteCache"]
@@ -65,5 +69,9 @@ let package = Package(
             dependencies: ["XCRemoteCache"],
             resources: [.copy("TestData")]
         ),
+        .testTarget(
+            name: "xclibtoolSupportTests",
+            dependencies: ["xclibtoolSupport"]
+        ),
     ]
 )

Sources/XCRemoteCache/Commands/Libtool/XCLibtool.swift

@@ -20,7 +20,7 @@
 import Foundation
 
 /// Represents a mode that libtool was called
-public enum XCLibtoolMode {
+public enum XCLibtoolMode: Equatable {
     /// Creating a static library (ar format) from a set of .o input files
     case createLibrary(output: String, filelist: String, dependencyInfo: String)
     /// Creating a universal library (multiple-architectures) from a set of input .a static libraries

Sources/xclibtool/XCLibtoolMain.swift

@@ -18,53 +18,24 @@
 // under the License.
 
 import Foundation
+import xclibtoolSupport
 import XCRemoteCache
 
+public enum XCLibtoolMainError: Error {
+    case missingOutput
+    case unsupportedMode
+}
+
 /// Wrapper for a `libtool` program that copies the build executable (e.g. .a) from a cached-downloaded location
 /// Fallbacks to a standard `libtool` when the Ramote cache is not applicable (e.g. modified sources)
 public class XCLibtoolMain {
+    public init() { }
+
     public func main() {
         let args = ProcessInfo().arguments
-        var output: String?
-        // all input arguments library '.a'. Used to create an universal binary
-        var inputLibraries: [String] = []
-        var filelist: String?
-        var dependencyInfo: String?
-        var i = 0
-        while i < args.count {
-            switch args[i] {
-            case "-o":
-                output = args[i + 1]
-                i += 1
-            case "-filelist":
-                filelist = args[i + 1]
-                i += 1
-            case "-dependency_info":
-                dependencyInfo = args[i + 1]
-                i += 1
-            case let input where input.hasSuffix(".a"):
-                inputLibraries.append(input)
-            default:
-                break
-            }
-            i += 1
-        }
-        guard let outputInput = output else {
-            exit(1, "Missing 'output' argument. Args: \(args)")
-        }
 
-        let mode: XCLibtoolMode
-        if let filelistInput = filelist, let dependencyInfoInput = dependencyInfo {
-            // libtool is creating a library
-            mode = .createLibrary(output: outputInput, filelist: filelistInput, dependencyInfo: dependencyInfoInput)
-        } else if !inputLibraries.isEmpty {
-            // multiple input libraries suggest creating an universal binary
-            mode = .createUniversalBinary(output: outputInput, inputs: inputLibraries)
-        } else {
-            // unknown mode
-            exit(1, "Unsupported mode. Args: \(args)")
-        }
         do {
+            let mode = try XCLibtoolHelper.buildMode(args: args)
             try XCLibtool(mode).run()
         } catch {
             exit(1, "Failed with: \(error). Args: \(args)")

Sources/xclibtoolSupport/XCLibtoolHelper.swift

@@ -0,0 +1,72 @@
+// Copyright (c) 2023 Spotify AB.
+//
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+import Foundation
+import XCRemoteCache
+
+public enum XCLibtoolHelperError: Error {
+    case missingOutput
+    case unsupportedMode
+}
+
+public class XCLibtoolHelper {
+    public static func buildMode(args: [String]) throws -> XCLibtoolMode {
+        var output: String?
+        // all input arguments library '.a'. Used to create an universal binary
+        var inputLibraries: [String] = []
+        var filelist: String?
+        var dependencyInfo: String?
+        var i = 0
+        while i < args.count {
+            switch args[i] {
+            case "-o":
+                output = args[i + 1]
+                i += 1
+            case "-filelist":
+                filelist = args[i + 1]
+                i += 1
+            case "-dependency_info":
+                dependencyInfo = args[i + 1]
+                i += 1
+            case let input where input.hasSuffix(".a"):
+                // Support for
+                inputLibraries.append(input)
+            default:
+                break
+            }
+            i += 1
+        }
+        guard let outputInput = output else {
+            throw XCLibtoolHelperError.missingOutput
+        }
+
+        let mode: XCLibtoolMode
+        if let filelistInput = filelist, let dependencyInfoInput = dependencyInfo {
+            // libtool is creating a library
+            mode = .createLibrary(output: outputInput, filelist: filelistInput, dependencyInfo: dependencyInfoInput)
+        } else if !inputLibraries.isEmpty {
+            // multiple input libraries suggest creating an universal binary
+            mode = .createUniversalBinary(output: outputInput, inputs: inputLibraries)
+        } else {
+            // unknown mode
+            throw XCLibtoolHelperError.unsupportedMode
+        }
+        return mode
+    }
+}

Tests/xclibtoolSupportTests/XCLibtoolHelperTests.swift

@@ -0,0 +1,66 @@
+// Copyright (c) 2023 Spotify AB.
+//
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+@testable import xclibtoolSupport
+import XCTest
+
+class XCLibtoolHelperTests: XCTestCase {
+//    func testStaticFrameworkUniversalBinary() throws {
+//        let mode = try XCLibtoolHelper.buildMode(
+//            args: ["-o", "/universal/static", "/arch1/static", "arch2/static"]
+//        )
+//
+//        XCTAssertEqual(mode, .createUniversalBinary(
+//            output: "/universal/static",
+//            inputs: ["/arch1/static", "arch2/static"]
+//        ))
+//    }
+//
+//    func testStaticLibraryUniversalBinary() throws {
+//        let mode = try XCLibtoolHelper.buildMode(
+//            args: ["-o", "/universal/static.a", "/arch1/static.a", "arch2/static.a"]
+//        )
+//
+//        XCTAssertEqual(mode, .createUniversalBinary(
+//            output: "/universal/static.a",
+//            inputs: ["/arch1/static.a", "arch2/static.a"]
+//        ))
+//    }
+//
+//    func testUnknownExtensionInputThrowsUnsupportedMode() throws {
+//        XCTAssertThrowsError(try XCLibtoolHelper.buildMode(
+//            args: ["-o", "/universal/static.a", "/arch1/static.unknown"])) { error in
+//            switch error {
+//            case XCLibtoolHelperError.unsupportedMode: break
+//            default:
+//                XCTFail("Not expected error")
+//            }
+//        }
+//    }
+//
+//    func testMissingOutputThrowsMissingOutput() throws {
+//        XCTAssertThrowsError(try XCLibtoolHelper.buildMode(args: ["/arch1/static"])) { error in
+//            switch error {
+//            case XCLibtoolHelperError.missingOutput: break
+//            default:
+//                XCTFail("Not expected error")
+//            }
+//        }
+//    }
+}