Improve handling of "extra" files

In swiftlang#1507, we started adding "extra" files to the generated Xcode
project. This makes some enhancements to that feature:

- Introduce a new flag `--skip-extra-files` to go back to the pre-4.2
behaviour (best behaviour) of not including these files at all
- Do not add a file reference for "Package.resolved" since this
shouldn't be edited by hand and most people also never have to read it
- Move the "extra" file references after the products group. This may be
debatable, but I think it more clean to have all file references related
to the package manifest grouped together at the top instead of having
these interspersed throughout the main group.

Author: neonichu

Sources/Commands/SwiftPackageTool.swift

@@ -373,9 +373,13 @@ public class SwiftPackageTool: SwiftTool<PackageToolOptions> {
             generateXcodeParser.add(
                 option: "--watch", kind: Bool.self,
                 usage: "Watch for changes to the Package manifest to regenerate the Xcode project"),
+            generateXcodeParser.add(
+                option: "--skip-extra-files", kind: Bool.self,
+                usage: "Do not add file references for extra files to the generated Xcode project"),
             to: {
                 $0.xcodeprojOptions.useLegacySchemeGenerator = $1 ?? false
                 $0.xcodeprojOptions.enableAutogeneration = $2 ?? false
+                $0.xcodeprojOptions.addExtraFiles = !($3 ?? false)
             })
 
         let completionToolParser = parser.add(

Sources/Xcodeproj/generate().swift

@@ -34,6 +34,9 @@ public struct XcodeprojOptions {
     /// Run watchman to auto-generate the project file on changes.
     public var enableAutogeneration: Bool
 
+    /// Whether to add extra files to the generated project.
+    public var addExtraFiles: Bool
+
     /// Reference to manifest loader, if present.
     public var manifestLoader: ManifestLoader?
 
@@ -42,13 +45,15 @@ public struct XcodeprojOptions {
         xcconfigOverrides: AbsolutePath? = nil,
         isCodeCoverageEnabled: Bool? = nil,
         useLegacySchemeGenerator: Bool? = nil,
-        enableAutogeneration: Bool? = nil
+        enableAutogeneration: Bool? = nil,
+        addExtraFiles: Bool? = nil
     ) {
         self.flags = flags
         self.xcconfigOverrides = xcconfigOverrides
         self.isCodeCoverageEnabled = isCodeCoverageEnabled ?? false
         self.useLegacySchemeGenerator = useLegacySchemeGenerator ?? false
         self.enableAutogeneration = enableAutogeneration ?? false
+        self.addExtraFiles = addExtraFiles ?? true
     }
 }
 
@@ -83,14 +88,20 @@ public func generate(
     try makeDirectories(xcodeprojPath)
     try makeDirectories(schemesDir)
 
-    // Find the paths of any extra directories that should be added as folder
-    // references in the project.
-    let extraDirs = try findDirectoryReferences(path: srcroot)
-
+    let extraDirs: [AbsolutePath]
     var extraFiles = [AbsolutePath]()
-    if try repositoryProvider.checkoutExists(at: srcroot) {
-        let workingCheckout = try repositoryProvider.openCheckout(at: srcroot)
-        extraFiles = try getExtraFilesFor(package: graph.rootPackages[0], in: workingCheckout)
+
+    if options.addExtraFiles {
+        // Find the paths of any extra directories that should be added as folder
+        // references in the project.
+        extraDirs = try findDirectoryReferences(path: srcroot)
+
+        if try repositoryProvider.checkoutExists(at: srcroot) {
+            let workingCheckout = try repositoryProvider.openCheckout(at: srcroot)
+            extraFiles = try getExtraFilesFor(package: graph.rootPackages[0], in: workingCheckout)
+        }
+    } else {
+        extraDirs = []
     }
 
     /// Generate the contents of project.xcodeproj (inside the .xcodeproj).
@@ -265,6 +276,7 @@ func findNonSourceFiles(path: AbsolutePath, recursively: Bool = false) throws ->
     return filesFromPath.filter({
         if !isFile($0) { return false }
         if $0.basename.hasPrefix(".") { return false }
+        if $0.basename == "Package.resolved" { return false }
         if let `extension` = $0.extension, SupportedLanguageExtension.validExtensions.contains(`extension`) {
             return false
         }

Sources/Xcodeproj/pbxproj().swift

@@ -319,17 +319,6 @@ func xcodeProject(
     // Create a `Tests` group for the source targets in the root package.
     createSourceGroup(named: "Tests", for: testModules, in: project.mainGroup)
 
-    // Add "blue folders" for any other directories at the top level (note that
-    // they are not guaranteed to be direct children of the root directory).
-    for extraDir in extraDirs {
-        project.mainGroup.addFileReference(path: extraDir.relative(to: sourceRootDir).asString, pathBase: .projectDir)
-    }
-
-    for extraFile in extraFiles {
-        let groupOfFile = srcPathsToGroups[extraFile.parentDirectory]
-        groupOfFile?.addFileReference(path: extraFile.basename)
-    }
-
     // Determine the set of targets to generate in the project by excluding
     // any system targets.
     let targets = graph.reachableTargets.filter({ $0.type != .systemModule })
@@ -372,6 +361,17 @@ func xcodeProject(
     // the various targets; these references will be added to the link phases.
     let productsGroup = project.mainGroup.addGroup(path: "", pathBase: .buildDir, name: "Products")
 
+    // Add "blue folders" for any other directories at the top level (note that
+    // they are not guaranteed to be direct children of the root directory).
+    for extraDir in extraDirs {
+        project.mainGroup.addFileReference(path: extraDir.relative(to: sourceRootDir).asString, pathBase: .projectDir)
+    }
+
+    for extraFile in extraFiles {
+        let groupOfFile = srcPathsToGroups[extraFile.parentDirectory]
+        groupOfFile?.addFileReference(path: extraFile.basename)
+    }
+
     // Set the newly created `Products` group as the official products group of
     // the project.
     project.productGroup = productsGroup

Tests/XcodeprojTests/GenerateXcodeprojTests.swift

@@ -231,6 +231,9 @@ class GenerateXcodeprojTests: XCTestCase {
             let project = try Xcodeproj.generate(projectName: projectName, xcodeprojPath: outpath, graph: graph, options: XcodeprojOptions(), diagnostics: diagnostics)
 
             XCTAssertTrue(project.mainGroup.subitems.contains { $0.path == "a.txt" })
+
+            let projectWithoutExtraFiles = try Xcodeproj.generate(projectName: projectName, xcodeprojPath: outpath, graph: graph, options: XcodeprojOptions(addExtraFiles: false), diagnostics: diagnostics)
+            XCTAssertFalse(projectWithoutExtraFiles.mainGroup.subitems.contains { $0.path == "a.txt" })
         }
     }