Draft: Synapse and MSC2716 edits (explore the DAG)

[MadLittleMods]

Edits to make TARDIS work with Synapse while writing Complement tests for MSC2716.

• Add endpoints for backfilling history (MSC2716) synapse#9247
• Add tests for MSC2716 and backfilling history complement#68

Changes needed in Synapse

In Synapse, comment out all of the dropped fields in the event serialization in Synapse synapse/events/utils.py#L253-L259.

Changes needed in your Complement test

contextRes := alice.MustDoFunc(t, "GET", []string{"_matrix", "client", "r0", "rooms", roomID, "context", eventStar}, client.WithContentType("application/json"), client.WithQueries(url.Values{
	"limit": []string{"100"},
}))
contextResBody := client.ParseJSON(t, contextRes)
logrus.WithFields(logrus.Fields{
	"contextResBody": string(contextResBody),
}).Error("context res")

Previous before functional client API

contextRes := alice.MustDoRaw(t, "GET", []string{"_matrix", "client", "r0", "rooms", roomID, "context", eventStar}, nil, "application/json", url.Values{
	"limit": []string{"100"},
})
contextResBody := client.ParseJSON(t, contextRes)
logrus.WithFields(logrus.Fields{
	"contextResBody": string(contextResBody),
}).Error("context res")

Copy the output of that log line and paste it in the src/context-response.json file. (Replace the \" with ")

[MadLittleMods]

This data produces the following chart:

[MadLittleMods]

Updated DAG visualization with depth. See matrix-org/complement#68 (comment) for full context