fix(core/httpAuthSchemes): default sigv4aSigningRegionSet to undefined (#6375)

Author: kuhe

packages/core/src/submodules/httpAuthSchemes/aws_sdk/resolveAwsSdkSigV4AConfig.spec.ts

@@ -0,0 +1,10 @@
+import { resolveAwsSdkSigV4AConfig } from "./resolveAwsSdkSigV4AConfig";
+
+describe(resolveAwsSdkSigV4AConfig.name, () => {
+  it("should normalize provider but default to undefined value", async () => {
+    const config = resolveAwsSdkSigV4AConfig({});
+
+    expect(typeof config.sigv4aSigningRegionSet).toEqual("function");
+    expect(await config.sigv4aSigningRegionSet()).toEqual(undefined);
+  });
+});

packages/core/src/submodules/httpAuthSchemes/aws_sdk/resolveAwsSdkSigV4AConfig.ts

@@ -39,7 +39,7 @@ export interface AwsSdkSigV4AAuthResolvedConfig {
 export const resolveAwsSdkSigV4AConfig = <T>(
   config: T & AwsSdkSigV4AAuthInputConfig & AwsSdkSigV4APreviouslyResolved
 ): T & AwsSdkSigV4AAuthResolvedConfig => {
-  config.sigv4aSigningRegionSet = normalizeProvider(config.sigv4aSigningRegionSet ?? []);
+  config.sigv4aSigningRegionSet = normalizeProvider(config.sigv4aSigningRegionSet);
   return config as T & AwsSdkSigV4AAuthResolvedConfig;
 };