Covering edge cases

IBM-Swift · Mar 18, 2017 · 79c674f · 79c674f
1 parent f4baae1
commit 79c674f
Showing 1 changed file with 13 additions and 2 deletions.
diff --git a/Sources/ServiceCredentials.swift b/Sources/ServiceCredentials.swift
@@ -39,13 +39,20 @@ public struct ServiceCredentials {
     private static func trimURL(_ url: String) -> String {
         let trimmedURL = ServiceCredentials.removeTrailingSlash(from: url)
 
-        let alertIndex = trimmedURL.index(trimmedURL.startIndex, offsetBy: trimmedURL.characters.count-10)
-        let messageIndex = trimmedURL.index(trimmedURL.startIndex, offsetBy: trimmedURL.characters.count-12)
+        if trimmedURL.characters.count < 10 {
+            return trimmedURL
+        }
 
+        let alertIndex = trimmedURL.index(trimmedURL.startIndex, offsetBy: trimmedURL.characters.count-10)
         if trimmedURL.substring(from: alertIndex) == "/alerts/v1" {
             return trimmedURL.substring(to: alertIndex)
         }
 
+        if trimmedURL.characters.count < 12 {
+            return trimmedURL
+        }
+
+        let messageIndex = trimmedURL.index(trimmedURL.startIndex, offsetBy: trimmedURL.characters.count-12)
         if trimmedURL.substring(from: messageIndex) == "/messages/v1" {
             return trimmedURL.substring(to: messageIndex)
         }
@@ -55,6 +62,10 @@ public struct ServiceCredentials {
 
     // Trim off a trailing slash from the URL.
     private static func removeTrailingSlash(from url: String) -> String {
+        if url.characters.count < 1 {
+            return url
+        }
+
         var urlCopy = url
         var lastIndex = urlCopy.index(urlCopy.startIndex, offsetBy: urlCopy.characters.count-1)
         while urlCopy.characters.count > 1 && urlCopy[lastIndex] == "/" {