type enforcement

[rlankfo]

Description

The MeasurementEvent type specifies the value should be a number. The EventAttributes specify the attribute value should be a string. The API will allow users to put anything for these values I believe. Is it possible to enforce these types on the client side before the data is sent to the receiver?

https://github.com/grafana/faro-web-sdk/blob/a462a95d24410ed90dd9b66c1226d50684fc74dc/packages/core/src/api/measurements/types.ts#L3 https://github.com/grafana/faro-web-sdk/blob/a462a95d24410ed90dd9b66c1226d50684fc74dc/packages/core/src/api/events/types.ts#L3

The current receiver implementation will fail to deserialize requests if these types aren't enforced: https://github.com/grafana/agent/blob/main/pkg/integrations/v2/app_agent_receiver/payload.go#L202 https://github.com/grafana/agent/blob/main/pkg/integrations/v2/app_agent_receiver/payload.go#L346

Proposed solution

On the client side, perhaps typeof could be used to determine if the value is correct? I'm not 100% sure what the best solution would be.

In addition to enforcing this as much as possible on the client side, I propose that this is fixed in the receiver as well to allow any type that is sent because everything ends up stored in loki as a string.

Context

Here's an example:

    let quantity = 100;
    faro.api.pushEvent('add-to-cart', {
      'productId': productId,
      'quantity': quantity,
    });

Here quantity is a number. This results in a 400 from the receiver because it will fail to deserialize the request.