OpenAPI: Timestamps should be int64

[KitsuneRal]

The following (not conclusively exhaustive) list has timestamps of integer type with no specified format. When format is not specified, Swagger falls back to JSON Schema for type definitions. JSON Schema conveniently says that integers should be distinguished from floating-point numbers, and stops at that.

The conclusion from the above is that we should be clear which integer is used in each particular place. This issue is about timestamps, which should always be int64. The question is - do we need an MSC here or would a clarification be enough.

• client-server/notifications.yaml
• event-schemas/schema/m.receipt (this one defines ts as number, not following JSON Schema's spirit; but there's no way to specify precision in JSON Schema so perhaps it's safer to leave it as is).
• identity/lookup.yaml
• identity/associations.yaml
• identity/v2_associations.yaml
• push-gateway/push_notifier.yaml

[turt2live]

This is another case where the canonical JSON spec disagrees with what we're trying to do with it. https://spec.matrix.org/v1.2/appendices/#signing-json

related: #1085

[KitsuneRal]

int64 stores values corresponding to the range specified in the Canonical JSON text, doesn't it?

[turt2live]

The spec holds 2^53, not 2^64

[KitsuneRal]

I should learn arithmetics, it seems.

That being said, int64 would still be the best fitting format from Swagger perspective, and server-side validations would guard against numbers out of Canonical JSON range.