PackageManager: Fix bug preventing certain package descriptions from …

…being parsed

This patch fixes a bug that prevented `PackageManager` from parsing certain package
description files, since it made too many assumptions about its format. The new
parsing code is simpler, and a lot more robust, by scanning the package description
line-by-line until it finds a name definition.

Sources/MarathonCore/PackageManager.swift

@@ -233,21 +233,25 @@ internal final class PackageManager {
 
     private func nameOfPackage(in folder: Folder) throws -> String {
         let packageFile = try folder.file(named: "Package.swift")
-        var packageDescription = try packageFile.readAsString()
 
-        guard let nameStartRange = packageDescription.range(of: "name:") else {
-            throw Error.failedToReadPackageFile(packageFile.nameExcludingExtension)
-        }
+        for line in try packageFile.readAsString().components(separatedBy: .newlines) {
+            guard let nameTokenRange = line.range(of: "name:") else {
+                continue
+            }
 
-        packageDescription = packageDescription.substring(from: nameStartRange.upperBound)
+            var line = line.substring(from: nameTokenRange.upperBound)
+
+            if let range = line.range(of: ",") {
+                line = line.substring(to: range.lowerBound)
+            } else if let range = line.range(of: ")") {
+                line = line.substring(to: range.lowerBound)
+            }
 
-        guard let delimiterRange = packageDescription.range(of: ",") ?? packageDescription.range(of: ")") else {
-            throw Error.failedToReadPackageFile(packageFile.nameExcludingExtension)
+            line = line.trimmingCharacters(in: .whitespacesAndNewlines)
+            return line.replacingOccurrences(of: "\"", with: "")
         }
 
-        packageDescription = packageDescription.substring(to: delimiterRange.lowerBound)
-        packageDescription = packageDescription.trimmingCharacters(in: .whitespacesAndNewlines)
-        return packageDescription.replacingOccurrences(of: "\"", with: "")
+        throw Error.failedToReadPackageFile(packageFile.name)
     }
 
     private func nameOfRemotePackage(at url: URL) throws -> String {

Tests/MarathonTests/MarathonTests.swift

@@ -106,6 +106,32 @@ class MarathonTests: XCTestCase {
         try XCTAssertEqual(folder.subfolder(named: "Packages").files.count, 0)
     }
 
+    func testAddingLocalPackage() throws {
+        let packageFolder = try folder.createSubfolder(named: "TestPackage")
+        try packageFolder.moveToAndPerform(command: "swift package init")
+
+        let packageDescription = "import PackageDescription\n" +
+                                 "let package = Package(name: \"TestPackage\")"
+
+        let packageFile = try packageFolder.file(named: "Package.swift")
+        try packageFile.write(string: packageDescription)
+
+        let gitCommand = "git init && git add . && git commit -a -m \"Commit\" && git tag 0.1.0"
+        try packageFolder.moveToAndPerform(command: gitCommand)
+
+        try run(with: ["add", "TestPackage"])
+        XCTAssertNotNil(try? folder.subfolder(named: "Packages").file(named: "TestPackage").read())
+
+        let generatedFolder = try folder.subfolder(atPath: "Packages/Generated")
+
+        let generatedPackageFile = try generatedFolder.file(named: "Package.swift")
+        try XCTAssertTrue(generatedPackageFile.readAsString().contains(packageFolder.path))
+
+        let packageNames = try generatedFolder.subfolder(atPath: ".build/checkouts").subfolders.names
+        XCTAssertEqual(packageNames.count, 1)
+        XCTAssertTrue(packageNames.contains { $0.hasPrefix("TestPackage-") })
+    }
+
     func testAddingLocalPackageWithDependency() throws {
         let packageFolder = try folder.createSubfolder(named: "TestPackage")
         try packageFolder.moveToAndPerform(command: "swift package init")