Add support for getting a customer by external id

.changeset/funny-starfishes-swim.md

@@ -0,0 +1,5 @@
+---
+'@team-plain/typescript-sdk': minor
+---
+
+Add support for getCustomerByExternalId

src/client.ts

@@ -23,6 +23,7 @@ import {
   CreateThreadEventDocument,
   CreateWebhookTargetDocument,
   CustomerByEmailDocument,
+  CustomerByExternalIdDocument,
   CustomerByIdDocument,
   type CustomerCardConfigPartsFragment,
   CustomerCustomerGroupsDocument,
@@ -221,6 +222,25 @@ export class PlainClient {
     });
   }
 
+  /**
+   * If the customer is not found this will return null.
+   */
+  async getCustomerByExternalId(
+    variables: VariablesOf<typeof CustomerByExternalIdDocument>
+  ): SDKResult<CustomerPartsFragment | null> {
+    const res = await request(this.#ctx, {
+      query: CustomerByExternalIdDocument,
+      variables,
+    });
+
+    return unwrapData(res, (q) => {
+      if (!q.customerByExternalId) {
+        return null;
+      }
+      return q.customerByExternalId;
+    });
+  }
+
   /**
    * If the customer is not found this will return null.
    */

src/graphql/queries/customerByExternalId.gql

@@ -0,0 +1,5 @@
+query customerByExternalId($externalId: ID!) {
+  customerByExternalId(externalId: $externalId) {
+    ...CustomerParts
+  }
+}