Load CSS from package resource when available

Author: mattt

.node/package.json

@@ -5,7 +5,7 @@
     "not dead"
   ],
   "scripts": {
-    "watch": "postcss -w ../Assets/**/*.css -o ../Resources/all.min.css --config ./postcss.config.js"
+    "watch": "postcss -w ../Assets/**/*.css -o ../Sources/swift-doc/Resources/all.min.css --config ./postcss.config.js"
   },
   "dependencies": {
     "cssnano": "^4.1.10",

Package.swift

@@ -43,6 +43,9 @@ let package = Package(
                 .product(name: "SwiftSyntaxHighlighter", package: "SwiftSyntaxHighlighter"),
                 .product(name: "Logging", package: "swift-log"),
                 .product(name: "LoggingGitHubActions", package: "LoggingGitHubActions")
+            ],
+            resources: [
+                .copy("Resources")
             ]
         ),
         .target(

Resources/all.min.css renamed to Sources/swift-doc/Resources/all.min.css

@@ -120,9 +120,26 @@ extension SwiftDoc {
         }
 
         if case .html = format {
-          let cssData = try fetchRemoteCSS()
-          let cssURL = outputDirectoryURL.appendingPathComponent("all.css")
-          try writeFile(cssData, to: cssURL)
+            let destinationURL = outputDirectoryURL.appendingPathComponent("all.css")
+
+            func fetchRemoteCSS() throws -> Data {
+              let url = URL(string: "https://raw.githubusercontent.com/SwiftDocOrg/swift-doc/master/Resources/all.min.css")!
+              return try Data(contentsOf: url)
+            }
+
+            #if swift(>=5.3)
+            if let resourceURL = Bundle.module.url(forResource: "all.min", withExtension: "css") {
+                if !fileManager.fileExists(atPath: destinationURL.path) {
+                    try fileManager.copyItem(at: resourceURL, to: destinationURL)
+                }
+            } else {
+                let cssData = try fetchRemoteCSS()
+                try writeFile(cssData, to: destinationURL)
+            }
+            #else
+            let cssData = try fetchRemoteCSS()
+            try writeFile(cssData, to: destinationURL)
+            #endif
         }
 
       } catch {
@@ -131,8 +148,3 @@ extension SwiftDoc {
     }
   }
 }
-
-func fetchRemoteCSS() throws -> Data {
-  let url = URL(string: "https://raw.githubusercontent.com/SwiftDocOrg/swift-doc/master/Resources/all.min.css")!
-  return try Data(contentsOf: url)
-}