Simplify String.prefix(…) call in CommandParser.swift.

rgoldberg · rgoldberg · commit f5ebfb553361 · 2025-05-18T19:02:35.000-04:00
Signed-off-by: Ross Goldberg &lt;484615+rgoldberg@users.noreply.github.com&gt;
diff --git a/Sources/ArgumentParser/Parsing/CommandParser.swift b/Sources/ArgumentParser/Parsing/CommandParser.swift
@@ -465,12 +465,7 @@ extension CommandParser {
       let completingPrefix: String
       if let completingArgument = args.last {
         completingPrefix = String(
-          completingArgument.prefix(
-            upTo: completingArgument.index(
-              completingArgument.startIndex,
-              offsetBy: cursorIndexWithinCompletingArgument
-            )
-          )
+          completingArgument.prefix(cursorIndexWithinCompletingArgument)
         )
       } else if cursorIndexWithinCompletingArgument == 0 {
         completingPrefix = ""
