Allow the API to create customers

lib/bigcommerce/api/customers/handlers/create-customer.ts

@@ -0,0 +1,36 @@
+import { CustomersHandlers } from '..'
+
+const createCustomer: CustomersHandlers['createCustomer'] = async ({
+  res,
+  body: { firstName, lastName, email, password },
+  config,
+}) => {
+  // TODO: Add proper validations with something like Ajv
+  if (!(firstName && lastName && email && password)) {
+    return res.status(400).json({
+      data: null,
+      errors: [{ message: 'Invalid request' }],
+    })
+  }
+  // TODO: validate the password.
+  // Passwords must be at least 7 characters and contain both alphabetic
+  // and numeric characters.
+
+  const { data } = await config.storeApiFetch('/v3/customers', {
+    method: 'POST',
+    body: JSON.stringify([
+      {
+        first_name: firstName,
+        last_name: lastName,
+        email,
+        authentication: {
+          new_password: password,
+        },
+      },
+    ]),
+  })
+
+  res.status(200).json({ data })
+}
+
+export default createCustomer