Fixed handling objects as API input parameters

fix https://linear.app/tryghost/issue/SLO-155/paramsmap-is-not-a-function-an-unexpected-error-occurred-please-try

- in the case you provide an object to the API, this code will throw an
  error because it can't map over an object
- we can just assert that params should be an array and throw an error
  otherwise

ghost/api-framework/lib/utils/options.js

@@ -1,4 +1,5 @@
 const _ = require('lodash');
+const {IncorrectUsageError} = require('@tryghost/errors');
 
 /**
  * @description Helper function to prepare params for internal usages.
@@ -15,6 +16,14 @@ const trimAndLowerCase = (params) => {
         params = params.split(',');
     }
 
+    // If we don't have an array at this point, something is wrong, so we should throw an
+    // error to avoid trying to .map over something else
+    if (!_.isArray(params)) {
+        throw new IncorrectUsageError({
+            message: 'Params must be a string or array'
+        });
+    }
+
     return params.map((item) => {
         return item.trim().toLowerCase();
     });

ghost/api-framework/test/util/options.test.js

@@ -20,4 +20,12 @@ describe('util/options', function () {
     it('accepts parameters in form of an array', function () {
         optionsUtil.trimAndLowerCase(['  PeanUt', ' buTTer ']).should.eql(['peanut', 'butter']);
     });
+
+    it('throws error for invalid object input', function () {
+        try {
+            optionsUtil.trimAndLowerCase({name: 'peanut'});
+        } catch (err) {
+            err.message.should.eql('Params must be a string or array');
+        }
+    });
 });