feat(mailchimp): add mailchimp integration

packages/backend/src/apps/mailchimp/common/add-auth-header.js

@@ -0,0 +1,12 @@
+const addAuthHeader = ($, requestConfig) => {
+  if (
+    !requestConfig.additionalProperties?.skipAddingAuthHeader &&
+    $.auth.data?.accessToken
+  ) {
+    requestConfig.headers.Authorization = `Bearer ${$.auth.data.accessToken}`;
+  }
+
+  return requestConfig;
+};
+
+export default addAuthHeader;

packages/backend/src/apps/mailchimp/common/get-current-user.js

@@ -0,0 +1,18 @@
+const getCurrentUser = async ($) => {
+  const { data: currentUser } = await $.http.get(
+    'https://login.mailchimp.com/oauth2/metadata',
+    {
+      headers: {
+        Authorization: `OAuth ${$.auth.data.accessToken}`,
+      },
+      additionalProperties: {
+        skipAddingAuthHeader: true,
+        skipAddingBaseUrl: true,
+      },
+    }
+  );
+
+  return currentUser;
+};
+
+export default getCurrentUser;

packages/backend/src/apps/mailchimp/common/set-base-url.js

@@ -0,0 +1,10 @@
+const setBaseUrl = ($, requestConfig) => {
+  const serverPrefix = $.auth.data.serverPrefix;
+  if (!requestConfig.additionalProperties?.skipAddingBaseUrl && serverPrefix) {
+    requestConfig.baseURL = `https://${serverPrefix}.api.mailchimp.com`;
+  }
+
+  return requestConfig;
+};
+
+export default setBaseUrl;