fix(rds-signer): don't overwrite default config with undefined values (#6166)

Co-authored-by: George Fu <[email protected]>

Author: batzz-00

packages/rds-signer/src/runtimeConfig.browser.ts

@@ -1,17 +1,17 @@
 import { Sha256 } from "@aws-crypto/sha256-browser";
 import { invalidProvider } from "@smithy/invalid-dependency";
 
-import { SignerConfig } from "./Signer";
+import type { SignerConfig } from "./Signer";
 
 /**
  * @internal
  */
 export const getRuntimeConfig = (config: SignerConfig) => {
   return {
     runtime: "browser",
-    sha256: config?.sha256 ?? Sha256,
-    credentials: invalidProvider("Credential is missing"),
-    region: invalidProvider("Region is missing"),
     ...config,
+    sha256: config?.sha256 ?? Sha256,
+    credentials: config?.credentials ?? invalidProvider("Credential is missing"),
+    region: config?.region ?? invalidProvider("Region is missing"),
   };
 };

packages/rds-signer/src/runtimeConfig.native.ts

@@ -1,17 +1,17 @@
 import { Sha256 } from "@aws-crypto/sha256-js";
 import { invalidProvider } from "@smithy/invalid-dependency";
 
-import { SignerConfig } from "./Signer";
+import type { SignerConfig } from "./Signer";
 
 /**
  * @internal
  */
 export const getRuntimeConfig = (config: SignerConfig) => {
   return {
     runtime: "react-native",
-    sha256: config?.sha256 ?? Sha256,
-    credentials: invalidProvider("Credential is missing"),
-    region: invalidProvider("Region is missing"),
     ...config,
+    sha256: config?.sha256 ?? Sha256,
+    credentials: config?.credentials ?? invalidProvider("Credential is missing"),
+    region: config?.region ?? invalidProvider("Region is missing"),
   };
 };

packages/rds-signer/src/runtimeConfig.ts

@@ -3,14 +3,15 @@ import { NODE_REGION_CONFIG_FILE_OPTIONS, NODE_REGION_CONFIG_OPTIONS } from "@sm
 import { Hash } from "@smithy/hash-node";
 import { loadConfig } from "@smithy/node-config-provider";
 
-import { SignerConfig } from "./Signer";
+import type { SignerConfig } from "./Signer";
 
 /**
  * @internal
  */
 export const getRuntimeConfig = (config: SignerConfig) => {
   return {
     runtime: "node",
+    ...config,
     sha256: config?.sha256 ?? Hash.bind(null, "sha256"),
     credentials:
       config?.credentials ??
@@ -23,6 +24,5 @@ export const getRuntimeConfig = (config: SignerConfig) => {
         ...NODE_REGION_CONFIG_FILE_OPTIONS,
         profile: config.profile,
       }),
-    ...config,
   };
 };