Add support to relative paths SourceRepository checkoutPath argument

Sources/SwiftDocC/SourceRepository/SourceRepository.swift

@@ -9,33 +9,42 @@
 */
 
 import Foundation
+import ArgumentParser
 
 /// A remote repository that hosts source code.
 public struct SourceRepository {
     /// The path at which the repository is cloned locally.
     public var checkoutPath: String
-    
+
     /// The base URL where the service hosts the repository's contents.
     public var sourceServiceBaseURL: URL
-    
+
     /// A function that formats a line number to be included in a URL.
     public var formatLineNumber: (Int) -> String
-    
+
     /// Creates a source code repository.
     /// - Parameters:
     ///   - checkoutPath: The path at which the repository is checked out locally and from which its symbol graphs were generated.
     ///   - sourceServiceBaseURL: The base URL where the service hosts the repository's contents.
     ///   - formatLineNumber: A function that formats a line number to be included in a URL.
-    public init(
+    public init (
         checkoutPath: String,
         sourceServiceBaseURL: URL,
         formatLineNumber: @escaping (Int) -> String
     ) {
-        self.checkoutPath = checkoutPath
+
+
+//        guard FileManager.default.directoryExists(atPath: checkoutPath) else {
+//            throw ValidationError("User provided checkout-path argument {checkoutPath} is invalid.")
+//        }
+        let absoluteCheckoutPath = URL(fileURLWithPath: checkoutPath).absoluteString
+        let startIndex = absoluteCheckoutPath.index(absoluteCheckoutPath.startIndex, offsetBy: 7)
+
+        self.checkoutPath = String(absoluteCheckoutPath[startIndex...])
         self.sourceServiceBaseURL = sourceServiceBaseURL
         self.formatLineNumber = formatLineNumber
     }
-    
+
     /// Formats a local source file URL to a URL hosted by the remote source code service.
     /// - Parameters:
     ///   - sourceFileURL: The location of the source file on disk.
@@ -45,7 +54,7 @@ public struct SourceRepository {
         guard sourceFileURL.path.hasPrefix(checkoutPath) else {
             return nil
         }
-        
+
         let path = sourceFileURL.path.dropFirst(checkoutPath.count).removingLeadingSlash
         return sourceServiceBaseURL
             .appendingPathComponent(path)
@@ -65,7 +74,7 @@ public extension SourceRepository {
             formatLineNumber: { line in "L\(line)" }
         )
     }
-    
+
     /// Creates a source repository hosted by the GitLab service.
     /// - Parameters:
     ///   - checkoutPath: The path of the local checkout.
@@ -77,7 +86,7 @@ public extension SourceRepository {
             formatLineNumber: { line in "L\(line)" }
         )
     }
-    
+
     /// Creates a source repository hosted by the BitBucket service.
     /// - Parameters:
     ///   - checkoutPath: The path of the local checkout.
@@ -89,7 +98,7 @@ public extension SourceRepository {
             formatLineNumber: { line in "lines-\(line)" }
         )
     }
-    
+
     /// Creates a source repository hosted by the device's filesystem.
     ///
     /// Use this source repository to format `doc-source-file://` links to files on the
@@ -98,7 +107,7 @@ public extension SourceRepository {
     /// This source repository uses a custom scheme to offer more control local source file navigation.
     static func localFilesystem() -> SourceRepository {
         SourceRepository(
-            checkoutPath: "",
+            checkoutPath: "/",
             // 2 slashes to specify an empty authority/host component and 1 slash to specify a base path at the root.
             sourceServiceBaseURL: URL(string: "doc-source-file:///")!,
             formatLineNumber: { line in "L\(line)" }