Don’t discard the return value of FileManager.createFile

Author: ahoppen

Sources/generate-swift-format/FileGenerator.swift

@@ -19,6 +19,10 @@ protocol FileGenerator {
   func write(into handle: FileHandle) throws
 }
 
+private struct FailedToCreateFileError: Error {
+  let url: URL
+}
+
 extension FileGenerator {
   /// Generates a file at the given URL, overwriting it if it already exists.
   func generateFile(at url: URL) throws {
@@ -27,7 +31,9 @@ extension FileGenerator {
       try fm.removeItem(at: url)
     }
 
-    fm.createFile(atPath: url.path, contents: nil, attributes: nil)
+    if !fm.createFile(atPath: url.path, contents: nil, attributes: nil) {
+      throw FailedToCreateFileError(url: url)
+    }
     let handle = try FileHandle(forWritingTo: url)
     defer { handle.closeFile() }
 

Tests/swift-formatTests/Utilities/FileIteratorTests.swift

@@ -70,7 +70,12 @@ extension FileIteratorTests {
     let fileURL = tmpURL(path)
     try FileManager.default.createDirectory(
       at: fileURL.deletingLastPathComponent(), withIntermediateDirectories: true)
-    FileManager.default.createFile(atPath: fileURL.path, contents: Data())
+    struct FailedToCreateFileError: Error {
+      let url: URL
+    }
+    if !FileManager.default.createFile(atPath: fileURL.path, contents: Data()) {
+      throw FailedToCreateFileError(url: fileURL)
+    }
   }
 
   /// Create a symlink between files or directories in the test's temporary space.