simplify

Source/AwsCommonRuntimeKit/crt/Utilities.swift

@@ -273,36 +273,11 @@ func withByteCursorFromStrings<Result>(
     }
 }
 
-public func scan<S: Sequence, U>(_ seq: S, _ initial: U, _ combine: (U, S.Element) -> U) -> [U] {
-    var result: [U] = []
-    result.reserveCapacity(seq.underestimatedCount)
-    var runningResult = initial
-    for element in seq {
-    runningResult = combine(runningResult, element)
-    result.append(runningResult)
-    }
-    return result
-}
-
-/// Note: this function and associated scan function above are copied verbatim from
-/// swift standard lib where its private. 
-public func withArrayOfCStrings<R>(
-    _ args: [String], _ body: ([UnsafeMutablePointer<CChar>?]) -> R
-) -> R {
-    let argsCounts = Array(args.map { $0.utf8.count + 1 })
-    let argsOffsets = [ 0 ] + scan(argsCounts, 0, +)
-    let argsBufferSize = argsOffsets.last!
-    var argsBuffer: [UInt8] = []
-    argsBuffer.reserveCapacity(argsBufferSize)
-    for arg in args {
-        argsBuffer.append(contentsOf: arg.utf8)
-        argsBuffer.append(0)
-    }
-    return argsBuffer.withUnsafeMutableBufferPointer { (argsBuffer) in
-        let ptr = UnsafeMutableRawPointer(argsBuffer.baseAddress!).bindMemory(
-        to: CChar.self, capacity: argsBuffer.count)
-        var cStrings: [UnsafeMutablePointer<CChar>?] = argsOffsets.map { ptr + $0 }
-        cStrings[cStrings.count - 1] = nil
-        return body(cStrings)
+func withByteCursorArrayFromStringArray<R>(
+    _ arg: [String], _ body: (UnsafePointer<aws_byte_cursor>, Int) -> R) -> R {
+    let cursors = arg.map { aws_byte_cursor_from_c_str($0) }
+    let len = cursors.count
+    return cursors.withUnsafeBufferPointer { cursorsPtr in 
+        return body(cursorsPtr.baseAddress!, len)
     }
 }

Source/AwsCommonRuntimeKit/sdkutils/endpoint/EndpointsRequestContext.swift

@@ -48,17 +48,6 @@ public class EndpointsRequestContext {
         }
     }
 
-    private func withByteCursorArrayFromStringArray<R>(
-        _ arg: [String], _ body: (UnsafeMutablePointer<aws_byte_cursor>, Int) -> R) -> R {
-        withArrayOfCStrings(arg) { cStrArr in
-            var cursors = cStrArr.map { aws_byte_cursor_from_c_str($0) }
-            let len = cursors.count
-            return cursors.withUnsafeMutableBufferPointer { cursorsPtr in 
-                return body(cursorsPtr.baseAddress!, len)
-            }
-        }
-    }
-
     /// Add a string array endpoint parameter to the request context
     /// - Parameters:
     ///   - name: The name of the parameter

Test/AwsCommonRuntimeKitTests/crt/Utilities.swift

@@ -0,0 +1,27 @@
+//  Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+//  SPDX-License-Identifier: Apache-2.0.
+
+import XCTest
+@testable import AwsCommonRuntimeKit
+import AwsCCommon
+
+class UtilitiesTests: XCBaseTestCase {
+
+    func testStringArrayToByteCursorArray() {
+        let strings1 = ["a", "b"]
+        withByteCursorArrayFromStringArray(strings1) { cursors, len in
+            XCTAssertEqual(len, 2)
+            for i in 0..<len {
+                withUnsafePointer(to: cursors[i]) { pointer in
+                    XCTAssertTrue(aws_byte_cursor_is_valid(pointer))
+                }
+            }
+        }
+
+        let strings2: [String] = []
+        withByteCursorArrayFromStringArray(strings2) { cursors, len in
+            XCTAssertEqual(len, 0)
+        }
+    }
+}
+

Test/AwsCommonRuntimeKitTests/sdkutils/EndpointsRuleEngineTests.swift

@@ -13,7 +13,7 @@ class EndpointsRuleEngineTests: XCBaseTestCase {
       "partitions": [
         {
           "id": "aws",
-          "regionRegex": "^(us|eu|ap|sa|ca|me|af)-\\w+-\\d+$",
+          "regionRegex": "^(us|eu|ap|sa|ca|me|af)\\-\\w+\\-\\d+$",
           "regions": {
             "af-south-1": {},
             "af-east-1": {},
@@ -288,5 +288,6 @@ class EndpointsRuleEngineTests: XCBaseTestCase {
       try! context.add(name: "Region", value: "us-west-2")
       try! context.add(name: "Boolean", value: true)
       try! context.add(name: "StringArray", value: ["a", "b"])
+      try! context.add(name: "StringArray", value: [])
     }
 }