Handle ENOEXEC error for shell scripts on MacOS

Signed-off-by: Timothy Johnson <[email protected]>

__tests__/__packages__/cli-test-utils/CHANGELOG.md

@@ -4,7 +4,7 @@ All notable changes to the Zowe CLI test utils package will be documented in thi
 
 ## Recent Changes
 
-- BugFix: Fixed an issue on MacOS where `runCliScript` method failed to run script that is missing shebang line. [#2314](https://github.com/zowe/zowe-cli/pull/2314)
+- BugFix: Improved the error message shown on MacOS when `runCliScript` method fails to run script that is missing shebang line. [#2314](https://github.com/zowe/zowe-cli/pull/2314)
 
 ## `8.1.1`
 

__tests__/__packages__/cli-test-utils/src/TestUtils.ts

@@ -10,6 +10,7 @@
 */
 
 import * as fs from "fs";
+import * as path from "path";
 import { spawnSync, SpawnSyncReturns, ExecFileException } from "child_process";
 import { ITestEnvironment } from "./environment/doc/response/ITestEnvironment";
 import { ICommandDefinition, IHandlerParameters } from "@zowe/imperative";
@@ -55,13 +56,16 @@ export function runCliScript(scriptPath: string, testEnvironment: ITestEnvironme
         } catch {
             fs.chmodSync(scriptPath, "755");
         }
-        return spawnSync(scriptPath, args, {
+        const response = spawnSync(scriptPath, args, {
             cwd: testEnvironment.workingDir,
             env: childEnv,
-            encoding: "buffer",
-            shell: true // Don't require shebangs on MacOS
+            encoding: "buffer"
         });
+        if (process.platform === "darwin" && (response.error as ExecFileException)?.errno === -8) {
+            throw new Error(`The script file ${path.basename(scriptPath)} failed to execute. Check that it starts with a shebang line.`);
+        }
 
+        return response;
     } else {
         throw new Error(`The script file ${scriptPath} doesn't exist`);