fix: support tokens by not overwriting with shim

Author: Hweinstock

packages/core/src/shared/awsClientBuilderV3.ts

@@ -160,13 +160,15 @@ export class AWSClientBuilderV3 {
         if (!opt.requestHandler) {
             opt.requestHandler = this.getHttpHandler()
         }
-        // TODO: add tests for refresh logic.
-        opt.credentials = async () => {
-            const creds = await shim.get()
-            if (creds.expiration && creds.expiration.getTime() < Date.now()) {
-                return shim.refresh()
+
+        if (!opt.credentials && !opt.token) {
+            opt.credentials = async () => {
+                const creds = await shim.get()
+                if (creds.expiration && creds.expiration.getTime() < Date.now()) {
+                    return shim.refresh()
+                }
+                return creds
             }
-            return creds
         }
 
         const service = new serviceOptions.serviceClient(opt)

packages/core/src/test/shared/awsClientBuilderV3.test.ts

@@ -329,6 +329,16 @@ describe('AwsClientBuilderV3', function () {
             mockCredsShim.update(newerCreds)
             assert.strictEqual(await service.config.credentials(), newerCreds)
         })
+
+        it('does not initialize credentials if token is provided', function () {
+            const service = builder.createAwsService({
+                serviceClient: Client,
+                clientOptions: {
+                    token: { token: 'my-token', expiration: new Date(Date.now() + oneDay) },
+                },
+            })
+            assert.ok(service.config.credentials === undefined)
+        })
     })
 })