type testing with createInstance

packages/paypal-js/types/v6/index.d.ts

@@ -47,9 +47,8 @@ export type PageTypes =
     | "product-listing"
     | "search-results";
 
-export type CreateInstanceOptions<T extends readonly Components[]> = {
+type BaseCreateInstanceOptions<T extends readonly Components[]> = {
     clientMetadataId?: string;
-    clientToken: string;
     components: T;
     locale?: string;
     pageType?: PageTypes;
@@ -58,6 +57,18 @@ export type CreateInstanceOptions<T extends readonly Components[]> = {
     testBuyerCountry?: string;
 };
 
+export type CreateInstanceOptions<T extends readonly Components[]> =
+    | (BaseCreateInstanceOptions<T> & {
+          clientId?: never;
+          merchantId?: never;
+          clientToken: string;
+      })
+    | (BaseCreateInstanceOptions<T> & {
+          clientId: string;
+          merchantId?: string | string[];
+          clientToken?: never;
+      });
+
 /**
  * Dynamically typed SDK instance based on the components array provided to createInstance.
  *

packages/paypal-js/types/v6/tests/paypal-payments.test.ts

@@ -22,11 +22,32 @@ async function main() {
         throw new Error("PayPal v6 namespace missing version property");
     }
 
+    // option 1 - auth with clientToken
     const sdkInstance = await paypal.createInstance({
         clientToken: "fakeValue",
         components: ["paypal-payments"],
     });
 
+    // option 2 - auth with clientId only
+    const sdkInstance2 = await paypal.createInstance({
+        clientId: "fakeValue",
+        components: ["paypal-payments"],
+    });
+
+    // option 3 - auth with clientId and single merchantId
+    const sdkInstance3 = await paypal.createInstance({
+        clientId: "fakeValue",
+        merchantId: "fakeValue",
+        components: ["paypal-payments"],
+    });
+
+    // option 4 - auth with clientId and many merchantIds
+    const sdkInstance4 = await paypal.createInstance({
+        clientId: "fakeValue",
+        merchantId: ["fakeValue", "fakeValue2", "fakeValue3"],
+        components: ["paypal-payments"],
+    });
+
     const paymentMethods = await sdkInstance.findEligibleMethods({
         currencyCode: "USD",
     });