Expose id string in SaveRuleRes

[aseure]

No description provided.

[aseure]

@maxiloc
Weird behaviour detected here:

• Even though the objectID field is Required according to the documentation, I can save a rule without defining it
• If I provide the field, I don't have the id field in the raw JSON response
• If I don't provide it, I still do not have the id field in the raw JSON response but I get "objectID":"rules" and it's always the same, even after multiple calls.

Any idea why? Should we document the field and/or rename it? If you don't have any clue, I'll ask Search API Squad.

[maxiloc]

The endpoint is /1/indexes/{indexName}/rules/{objectID} so objectID is should be required.

[aseure]

Waiting for an answer from Search API Squad, apparently it's a bug: we shouldn't be able to call this endpoint with an empty objectID.

[aseure]

After investigations, we have discovered that calling the Save a single rule endpoint with an empty objectID field for the rule is interpreted by the engine as a new record to index, whose objectID is rules, which maps to Add/Update an object by ID endpoint.

In other words, instead of saving a new rule with /1/indexes/{indexName}/rules/{objectID} with an empty objectID (even in the presence of the trailing slash after rules), we were actually calling /1/indexes/{indexName}/{objectID} with objectID set to rules, creating a new record instead.

As this routing issue cannot be fixed server-side, we will have to enforce it client-side, by checking that the given objectID is not empty. Same applies for all other API clients.

Thank you for helping me investigate @clement-leprovost and @Nagriar.

@maxiloc Regarding the original issue, I confirm that after a SaveRule call the expected response is only composed of the taskID/updatedAt fields, as correctly documented here (REST API) and incorrectly documented here (API method) (see https://github.com/algolia/doc/issues/1398 for the related issue in the documentation repository).