Cloud Datastore 'Index Not Found' error somewhat obscure

[OverclockedTim]

Using the gcloud-node library to do a query that cannot be fulfilled due to lack of indexing produces the obscure error 412, Precondition Failed error:

{ "code":412,"message":"Precondition Failed",...}

A FAQ or troubleshooting doc would be helpful, as would simply including a bit more information in the error itself. Something along the lines of "Precondition Failed: The request index required for this query is not found. To enable this query, please add it by <instructions/url-to-instructions/etc>

The Java Appengine version of this error message is extremely helpful and includes both the root cause of the error and instructions on how to create an appropriate index.

[stephenplusplus]

Thanks for the feedback! I just recently had the same thought: #1016 (comment)

When we return an error, if the response body is a string, we can append that to the error message that we return.

Before:

console.log(error);
// Precondition Failed

After:

console.log(error);
// Precondition Failed - no matching index found.

[stephenplusplus]

@callmehiphop is this a weird or good plan?

[callmehiphop]

It sounds like a good plan to me, what reasoning would make it weird?