80 lines
2.5 KiB
JavaScript
80 lines
2.5 KiB
JavaScript
// @ts-check
|
|
|
|
const assert = require("assert").strict
|
|
const mixin = require("mixin-deep")
|
|
const deepEqual = require("deep-equal")
|
|
|
|
/** Mutates the input. */
|
|
function kstateStripConditionals(kstate) {
|
|
for (const [k, content] of Object.entries(kstate)) {
|
|
// conditional for whether a key is even part of the kstate (doing this declaratively on json is hard, so represent it as a property instead.)
|
|
if ("$if" in content) {
|
|
if (content.$if) delete content.$if
|
|
else delete kstate[k]
|
|
}
|
|
}
|
|
return kstate
|
|
}
|
|
|
|
function kstateToState(kstate) {
|
|
const events = []
|
|
kstateStripConditionals(kstate)
|
|
for (const [k, content] of Object.entries(kstate)) {
|
|
const slashIndex = k.indexOf("/")
|
|
assert(slashIndex > 0)
|
|
const type = k.slice(0, slashIndex)
|
|
const state_key = k.slice(slashIndex + 1)
|
|
events.push({type, state_key, content})
|
|
}
|
|
return events
|
|
}
|
|
|
|
/**
|
|
* @param {import("../types").Event.BaseStateEvent[]} events
|
|
* @returns {any}
|
|
*/
|
|
function stateToKState(events) {
|
|
const kstate = {}
|
|
for (const event of events) {
|
|
kstate[event.type + "/" + event.state_key] = event.content
|
|
}
|
|
return kstate
|
|
}
|
|
|
|
function diffKState(actual, target) {
|
|
const diff = {}
|
|
// go through each key that it should have
|
|
for (const key of Object.keys(target)) {
|
|
if (!key.includes("/")) throw new Error(`target kstate's key "${key}" does not contain a slash separator; if a blank state_key was intended, add a trailing slash to the kstate key.\ncontext: ${JSON.stringify(target)}`)
|
|
|
|
if (key === "m.room.power_levels/") {
|
|
// Special handling for power levels, we want to deep merge the actual and target into the final state.
|
|
if (!(key in actual)) throw new Error(`want to apply a power levels diff, but original power level data is missing\nstarted with: ${JSON.stringify(actual)}\nwant to apply: ${JSON.stringify(target)}`)
|
|
const temp = mixin({}, actual[key], target[key])
|
|
if (!deepEqual(actual[key], temp, {strict: true})) {
|
|
// they differ. use the newly prepared object as the diff.
|
|
diff[key] = temp
|
|
}
|
|
|
|
} else if (key in actual) {
|
|
// diff
|
|
if (!deepEqual(actual[key], target[key], {strict: true})) {
|
|
// they differ. use the target as the diff.
|
|
diff[key] = target[key]
|
|
}
|
|
|
|
} else {
|
|
// not present, needs to be added
|
|
diff[key] = target[key]
|
|
}
|
|
|
|
// keys that are missing in "actual" will not be deleted on "target" (no action)
|
|
}
|
|
return diff
|
|
}
|
|
|
|
module.exports.kstateStripConditionals = kstateStripConditionals
|
|
module.exports.kstateToState = kstateToState
|
|
module.exports.stateToKState = stateToKState
|
|
module.exports.diffKState = diffKState
|