fix: removes explicit erroring when compiling on a future swift versi…

…on (#528)

* fix: removes explicit erroring when compiling on a future swift version

* Updates function names"

Sources/ClientRuntime/Util/SwiftVersion.swift

@@ -5,13 +5,29 @@
 // SPDX-License-Identifier: Apache-2.0
 //
 
+/// Returns the swift version of the compiler that is compiling this application.
 public var swiftVersion: String {
-    #if swift(>=5.8)
-      #error("""
-          Cannot use a version of Swift greater than available. \
-          Please create a Github issue for us to add support for the version of Swift you want to use.
-          """
-      )
+    /**
+     Unfortunately there isn't a way to grab the compiled swift programmatically and so we must resot to the compiler directives to produce a version string.
+     We are checking for quite a few versions in the future, that may never exist, in order to future proof our current SDKs. Ideally, all current SDKs should compile
+     on future Swift versions unless that Swift version introduces a breaking change.
+
+     TODO add handling for Swift 8.x versions when Swift 6.0 is released.
+     */
+    return swift5Version()
+    ?? swift6Version()
+    ?? swift7Version()
+    ?? "unknown"
+}
+
+
+fileprivate func swift5Version() -> String? {
+    #if swift(>=6.0)
+    return nil
+    #elseif swift(>=5.9)
+    return "5.9"
+    #elseif swift(>=5.8)
+    return "5.8"
     #elseif swift(>=5.7)
     return "5.7"
     #elseif swift(>=5.6)
@@ -29,6 +45,62 @@ public var swiftVersion: String {
     #elseif swift(>=5.0)
     return "5.0"
     #else
-      #error("Cannot use a version of Swift less than 5.0")
+    return nil
+    #endif
+}
+
+fileprivate func swift6Version() -> String? {
+    #if swift(>=7.0)
+    return nil
+    #elseif swift(>=6.9)
+    return "6.9"
+    #elseif swift(>=6.8)
+    return "6.8"
+    #elseif swift(>=6.7)
+    return "6.7"
+    #elseif swift(>=6.6)
+    return "6.6"
+    #elseif swift(>=6.5)
+    return "6.5"
+    #elseif swift(>=6.4)
+    return "6.4"
+    #elseif swift(>=6.3)
+    return "6.3"
+    #elseif swift(>=6.2)
+    return "6.2"
+    #elseif swift(>=6.1)
+    return "6.1"
+    #elseif swift(>=6.0)
+    return "6.0"
+    #else
+    return nil
+    #endif
+}
+
+fileprivate func swift7Version() -> String? {
+    #if swift(>=8.0)
+    return nil
+    #elseif swift(>=7.9)
+    return "7.9"
+    #elseif swift(>=7.8)
+    return "7.8"
+    #elseif swift(>=7.7)
+    return "7.7"
+    #elseif swift(>=7.6)
+    return "7.6"
+    #elseif swift(>=7.5)
+    return "7.5"
+    #elseif swift(>=7.4)
+    return "7.4"
+    #elseif swift(>=7.3)
+    return "7.3"
+    #elseif swift(>=7.2)
+    return "7.2"
+    #elseif swift(>=7.1)
+    return "7.1"
+    #elseif swift(>=7.0)
+    return "7.0"
+    #else
+    return nil
     #endif
 }