fix: Make AWS SDK CLI test runner fail when tests fail

AWSSDKSwiftCLI/Sources/AWSSDKSwiftCLI/Utils/Process+Utils.swift

@@ -6,6 +6,7 @@
 //
 
 import Foundation
+import ArgumentParser
 
 extension Process {
     /// Creates a process using `/usr/bin/env` as the executable
@@ -73,6 +74,10 @@ struct ProcessRunner {
         log("Running process: \(process.commandString)")
         try process.run()
         process.waitUntilExit()
+        let exitCode = ExitCode(process.terminationStatus)
+        if !exitCode.isSuccess {
+            throw exitCode
+        }
     }
 
     #if DEBUG

AWSSDKSwiftCLI/Tests/AWSSDKSwiftCLITests/Utils/ProcessUtilsTests.swift

@@ -0,0 +1,26 @@
+//
+// Copyright Amazon.com Inc. or its affiliates.
+// All Rights Reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+@testable import AWSSDKSwiftCLI
+import PackageDescription
+import ArgumentParser
+import XCTest
+
+class ProcessUtilsTests: XCTestCase {
+
+    func test_exit_itThrowsErrorWithErrorCode() {
+        let process = Process("false")  // this refers to /usr/bin/false which always returns unsuccessfully
+        do {
+            try ProcessRunner.standard.run(process)
+            XCTFail("Process runner should have thrown")
+        } catch let exitCodeError as ExitCode {
+            XCTAssertTrue(exitCodeError.rawValue != 0)
+        } catch {
+            XCTFail("Process runner threw an unexpected type of error")
+        }
+    }
+}