Add visual diffs to syncing (#603)

* Add user confirmation to initial sync

* Use "Accept" instead of "Confirm"

* Draw tree alphabetically for determinism

* Add diff table dropdown

* Add diff table to newly added objects

* Unblock keybind workflow

* Only show reject button when two way is enabled

* Try to patch back to the files when changes are rejected

* Improve text spacing of the prop diff table

* Skip user confirmation of perfect syncs

* Give instances names for debugging UI

* Optimize tree building

* Efficiency: dynamic virtual scrolling & lazy rendering

* Simplify virtual scroller logic and avoid wasteful rerenders

* Remove debug print

* Consistent naming

* Move new patch applied callback into accept

* Pcall archivable

* Keybinds open popup diff window

* Theme rows in diff

* Remove relic of prototype

* Color value visuals and better component name

* changeBatcher is not needed when no sync is active

* Simplify popup roact entrypoint

* Alphabetical prop lists and refactor

* Add a stroke to color blot for contrast

* Make color blots animate transparency with the rest of the page

* StyLua formatting on newly added files

* Remove wasteful table

* Fix diffing custom properties

* Display tables more meaningfully

* Allow children in the button components

* Create a rough tooltip component

* Add tooltips to buttons

* Use provider+trigger schema to avoid tooltip ZIndex issues

* Add triangle point to tooltip

* Tooltip underneath instead of covering

* Cancel hovers when unmounting

* Allow multiple canvases from one provider

* Display above or below depending on available space

* Move patch equality to PatchSet.isEqual

* Use Container

* Remove old submodules

* Reduce false positives in diff

* Add debug log

* Fuzzy equals CFrame in diffs to avoid floating point in

* Fix decodeValue usage

* Support the .changedName patches

* Fix content overlapping border

* Fix tooltip tail alignment

* Fix tooltip text fit

* Whoops, fix it properly

* Move PatchVisualizer to Components

* Provide Connected info with full patch data

* Avoid implicit nil return

* Add patch visualizer to connected page

* Make Current column invisible when visualizing applied patches

* Avoid floating point diffs in a numbers and vectors

plugin/src/App/Components/BorderedContainer.lua

@@ -24,7 +24,8 @@ local function BorderedContainer(props)
 			layoutOrder = props.layoutOrder,
 		}, {
 			Content = e("Frame", {
-				Size = UDim2.new(1, 0, 1, 0),
+				Size = UDim2.new(1, -2, 1, -2),
+				Position = UDim2.new(0, 1, 0, 1),
 				BackgroundTransparency = 1,
 				ZIndex = 2,
 			}, props[Roact.Children]),

plugin/src/App/Components/PatchVisualizer/ChangeList.lua

@@ -0,0 +1,181 @@
+local Rojo = script:FindFirstAncestor("Rojo")
+local Plugin = Rojo.Plugin
+local Packages = Rojo.Packages
+
+local Roact = require(Packages.Roact)
+
+local Theme = require(Plugin.App.Theme)
+local ScrollingFrame = require(Plugin.App.Components.ScrollingFrame)
+local DisplayValue = require(script.Parent.DisplayValue)
+
+local e = Roact.createElement
+
+local ChangeList = Roact.Component:extend("ChangeList")
+
+function ChangeList:init()
+	self.contentSize, self.setContentSize = Roact.createBinding(Vector2.new(0, 0))
+end
+
+function ChangeList:render()
+	return Theme.with(function(theme)
+		local props = self.props
+		local changes = props.changes
+
+		-- Color alternating rows for readability
+		local rowTransparency = props.transparency:map(function(t)
+			return 0.93 + (0.07 * t)
+		end)
+
+		local columnVisibility = props.columnVisibility
+
+		local rows = {}
+		local pad = {
+			PaddingLeft = UDim.new(0, 5),
+			PaddingRight = UDim.new(0, 5),
+		}
+
+		local headers = e("Frame", {
+			Size = UDim2.new(1, 0, 0, 30),
+			BackgroundTransparency = rowTransparency,
+			BackgroundColor3 = theme.Diff.Row,
+			LayoutOrder = 0,
+		}, {
+			Padding = e("UIPadding", pad),
+			Layout = e("UIListLayout", {
+				FillDirection = Enum.FillDirection.Horizontal,
+				SortOrder = Enum.SortOrder.LayoutOrder,
+				HorizontalAlignment = Enum.HorizontalAlignment.Left,
+				VerticalAlignment = Enum.VerticalAlignment.Center,
+			}),
+			A = e("TextLabel", {
+				Visible = columnVisibility[1],
+				Text = tostring(changes[1][1]),
+				BackgroundTransparency = 1,
+				Font = Enum.Font.GothamBold,
+				TextSize = 14,
+				TextColor3 = theme.Settings.Setting.DescriptionColor,
+				TextXAlignment = Enum.TextXAlignment.Left,
+				TextTransparency = props.transparency,
+				TextTruncate = Enum.TextTruncate.AtEnd,
+				Size = UDim2.new(0.3, 0, 1, 0),
+				LayoutOrder = 1,
+			}),
+			B = e("TextLabel", {
+				Visible = columnVisibility[2],
+				Text = tostring(changes[1][2]),
+				BackgroundTransparency = 1,
+				Font = Enum.Font.GothamBold,
+				TextSize = 14,
+				TextColor3 = theme.Settings.Setting.DescriptionColor,
+				TextXAlignment = Enum.TextXAlignment.Left,
+				TextTransparency = props.transparency,
+				TextTruncate = Enum.TextTruncate.AtEnd,
+				Size = UDim2.new(0.35, 0, 1, 0),
+				LayoutOrder = 2,
+			}),
+			C = e("TextLabel", {
+				Visible = columnVisibility[3],
+				Text = tostring(changes[1][3]),
+				BackgroundTransparency = 1,
+				Font = Enum.Font.GothamBold,
+				TextSize = 14,
+				TextColor3 = theme.Settings.Setting.DescriptionColor,
+				TextXAlignment = Enum.TextXAlignment.Left,
+				TextTransparency = props.transparency,
+				TextTruncate = Enum.TextTruncate.AtEnd,
+				Size = UDim2.new(0.35, 0, 1, 0),
+				LayoutOrder = 3,
+			}),
+		})
+
+		for row, values in changes do
+			if row == 1 then
+				continue -- Skip headers, already handled above
+			end
+
+			rows[row] = e("Frame", {
+				Size = UDim2.new(1, 0, 0, 30),
+				BackgroundTransparency = row % 2 ~= 0 and rowTransparency or 1,
+				BackgroundColor3 = theme.Diff.Row,
+				BorderSizePixel = 0,
+				LayoutOrder = row,
+			}, {
+				Padding = e("UIPadding", pad),
+				Layout = e("UIListLayout", {
+					FillDirection = Enum.FillDirection.Horizontal,
+					SortOrder = Enum.SortOrder.LayoutOrder,
+					HorizontalAlignment = Enum.HorizontalAlignment.Left,
+					VerticalAlignment = Enum.VerticalAlignment.Center,
+				}),
+				A = e("TextLabel", {
+					Visible = columnVisibility[1],
+					Text = tostring(values[1]),
+					BackgroundTransparency = 1,
+					Font = Enum.Font.GothamMedium,
+					TextSize = 14,
+					TextColor3 = theme.Settings.Setting.DescriptionColor,
+					TextXAlignment = Enum.TextXAlignment.Left,
+					TextTransparency = props.transparency,
+					TextTruncate = Enum.TextTruncate.AtEnd,
+					Size = UDim2.new(0.3, 0, 1, 0),
+					LayoutOrder = 1,
+				}),
+				B = e(
+					"Frame",
+					{
+						Visible = columnVisibility[2],
+						BackgroundTransparency = 1,
+						Size = UDim2.new(0.35, 0, 1, 0),
+						LayoutOrder = 2,
+					},
+					e(DisplayValue, {
+						value = values[2],
+						transparency = props.transparency,
+					})
+				),
+				C = e(
+					"Frame",
+					{
+						Visible = columnVisibility[3],
+						BackgroundTransparency = 1,
+						Size = UDim2.new(0.35, 0, 1, 0),
+						LayoutOrder = 3,
+					},
+					e(DisplayValue, {
+						value = values[3],
+						transparency = props.transparency,
+					})
+				),
+			})
+		end
+
+		table.insert(
+			rows,
+			e("UIListLayout", {
+				FillDirection = Enum.FillDirection.Vertical,
+				SortOrder = Enum.SortOrder.LayoutOrder,
+				HorizontalAlignment = Enum.HorizontalAlignment.Right,
+				VerticalAlignment = Enum.VerticalAlignment.Top,
+
+				[Roact.Change.AbsoluteContentSize] = function(object)
+					self.setContentSize(object.AbsoluteContentSize)
+				end,
+			})
+		)
+
+		return e("Frame", {
+			Size = UDim2.new(1, 0, 1, 0),
+			BackgroundTransparency = 1,
+		}, {
+			Headers = headers,
+			Values = e(ScrollingFrame, {
+				size = UDim2.new(1, 0, 1, -30),
+				position = UDim2.new(0, 0, 0, 30),
+				contentSize = self.contentSize,
+				transparency = props.transparency,
+			}, rows),
+		})
+	end)
+end
+
+return ChangeList

plugin/src/App/Components/PatchVisualizer/DisplayValue.lua

@@ -0,0 +1,107 @@
+local Rojo = script:FindFirstAncestor("Rojo")
+local Plugin = Rojo.Plugin
+local Packages = Rojo.Packages
+
+local Roact = require(Packages.Roact)
+
+local Theme = require(Plugin.App.Theme)
+
+local e = Roact.createElement
+
+local function DisplayValue(props)
+	return Theme.with(function(theme)
+		local t = typeof(props.value)
+		if t == "Color3" then
+			-- Colors get a blot that shows the color
+			return Roact.createFragment({
+				Blot = e("Frame", {
+					BackgroundTransparency = props.transparency,
+					BackgroundColor3 = props.value,
+					Size = UDim2.new(0, 20, 0, 20),
+					Position = UDim2.new(0, 0, 0.5, 0),
+					AnchorPoint = Vector2.new(0, 0.5),
+				}, {
+					Corner = e("UICorner", {
+						CornerRadius = UDim.new(0, 4),
+					}),
+					Stroke = e("UIStroke", {
+						Color = theme.BorderedContainer.BorderColor,
+						Transparency = props.transparency,
+					}),
+				}),
+				Label = e("TextLabel", {
+					Text = string.format("%d,%d,%d", props.value.R * 255, props.value.G * 255, props.value.B * 255),
+					BackgroundTransparency = 1,
+					Font = Enum.Font.GothamMedium,
+					TextSize = 14,
+					TextColor3 = theme.Settings.Setting.DescriptionColor,
+					TextXAlignment = Enum.TextXAlignment.Left,
+					TextTransparency = props.transparency,
+					TextTruncate = Enum.TextTruncate.AtEnd,
+					Size = UDim2.new(1, -25, 1, 0),
+					Position = UDim2.new(0, 25, 0, 0),
+				}),
+			})
+
+		elseif t == "table" then
+			-- Showing a memory address for tables is useless, so we want to show the best we can
+			local textRepresentation = nil
+
+			local meta = getmetatable(props.value)
+			if meta and meta.__tostring then
+				-- If the table has a tostring metamethod, use that
+				textRepresentation = tostring(props.value)
+			elseif next(props.value) == nil then
+				-- If it's empty, show empty braces
+				textRepresentation = "{}"
+			else
+				-- If it has children, list them out
+				local out, i = {}, 0
+				for k, v in pairs(props.value) do
+					i += 1
+
+					-- Wrap strings in quotes
+					if type(k) == "string" then
+						k = "\"" .. k .. "\""
+					end
+					if type(v) == "string" then
+						v = "\"" .. v .. "\""
+					end
+
+					out[i] = string.format("[%s] = %s", tostring(k), tostring(v))
+				end
+				textRepresentation = "{ " .. table.concat(out, ", ") .. " }"
+			end
+
+			return e("TextLabel", {
+				Text = textRepresentation,
+				BackgroundTransparency = 1,
+				Font = Enum.Font.GothamMedium,
+				TextSize = 14,
+				TextColor3 = theme.Settings.Setting.DescriptionColor,
+				TextXAlignment = Enum.TextXAlignment.Left,
+				TextTransparency = props.transparency,
+				TextTruncate = Enum.TextTruncate.AtEnd,
+				Size = UDim2.new(1, 0, 1, 0),
+			})
+		end
+
+		-- TODO: Maybe add visualizations to other datatypes?
+		-- Or special text handling tostring for some?
+		-- Will add as needed, let's see what cases arise.
+
+		return e("TextLabel", {
+			Text = string.gsub(tostring(props.value), "%s", " "),
+			BackgroundTransparency = 1,
+			Font = Enum.Font.GothamMedium,
+			TextSize = 14,
+			TextColor3 = theme.Settings.Setting.DescriptionColor,
+			TextXAlignment = Enum.TextXAlignment.Left,
+			TextTransparency = props.transparency,
+			TextTruncate = Enum.TextTruncate.AtEnd,
+			Size = UDim2.new(1, 0, 1, 0),
+		})
+	end)
+end
+
+return DisplayValue

plugin/src/App/Components/PatchVisualizer/DomLabel.lua

@@ -0,0 +1,180 @@
+local StudioService = game:GetService("StudioService")
+
+local Rojo = script:FindFirstAncestor("Rojo")
+local Plugin = Rojo.Plugin
+local Packages = Rojo.Packages
+
+local Roact = require(Packages.Roact)
+local Flipper = require(Packages.Flipper)
+
+local Assets = require(Plugin.Assets)
+local Theme = require(Plugin.App.Theme)
+local bindingUtil = require(Plugin.App.bindingUtil)
+
+local e = Roact.createElement
+
+local ChangeList = require(script.Parent.ChangeList)
+
+local Expansion = Roact.Component:extend("Expansion")
+
+function Expansion:render()
+	local props = self.props
+
+	if not props.rendered then
+		return nil
+	end
+
+	return e("Frame", {
+		BackgroundTransparency = 1,
+		Size = UDim2.new(1, -props.indent, 1, -30),
+		Position = UDim2.new(0, props.indent, 0, 30),
+	}, {
+		ChangeList = e(ChangeList, {
+			changes = props.changeList,
+			transparency = props.transparency,
+			columnVisibility = props.columnVisibility,
+		}),
+	})
+end
+
+local DomLabel = Roact.Component:extend("DomLabel")
+
+function DomLabel:init()
+	self.maxElementHeight = 0
+	if self.props.changeList then
+		self.maxElementHeight = math.clamp(#self.props.changeList * 30, 30, 30 * 6)
+	end
+
+	local initHeight = self.props.elementHeight:getValue()
+	self.expanded = initHeight > 30
+
+	self.motor = Flipper.SingleMotor.new(initHeight)
+	self.binding = bindingUtil.fromMotor(self.motor)
+
+	self:setState({
+		renderExpansion = self.expanded,
+	})
+	self.motor:onStep(function(value)
+		local renderExpansion = value > 30
+
+		self.props.setElementHeight(value)
+		if self.props.updateEvent then
+			self.props.updateEvent:Fire()
+		end
+
+		self:setState(function(state)
+			if state.renderExpansion == renderExpansion then
+				return nil
+			end
+
+			return {
+				renderExpansion = renderExpansion,
+			}
+		end)
+	end)
+end
+
+function DomLabel:render()
+	local props = self.props
+
+	return Theme.with(function(theme)
+		local iconProps = StudioService:GetClassIcon(props.className)
+		local indent = (props.depth or 0) * 20 + 25
+
+		-- Line guides help indent depth remain readable
+		local lineGuides = {}
+		for i = 1, props.depth or 0 do
+			table.insert(
+				lineGuides,
+				e("Frame", {
+					Name = "Line_" .. i,
+					Size = UDim2.new(0, 2, 1, 2),
+					Position = UDim2.new(0, (20 * i) + 15, 0, -1),
+					BorderSizePixel = 0,
+					BackgroundTransparency = props.transparency,
+					BackgroundColor3 = theme.BorderedContainer.BorderColor,
+				})
+			)
+		end
+
+		return e("Frame", {
+			Name = "Change",
+			ClipsDescendants = true,
+			BackgroundColor3 = if props.patchType then theme.Diff[props.patchType] else nil,
+			BorderSizePixel = 0,
+			BackgroundTransparency = props.patchType and props.transparency or 1,
+			Size = self.binding:map(function(expand)
+				return UDim2.new(1, 0, 0, expand)
+			end),
+		}, {
+			Padding = e("UIPadding", {
+				PaddingLeft = UDim.new(0, 10),
+				PaddingRight = UDim.new(0, 10),
+			}),
+			ExpandButton = if props.changeList
+				then e("TextButton", {
+					BackgroundTransparency = 1,
+					Text = "",
+					Size = UDim2.new(1, 0, 1, 0),
+					[Roact.Event.Activated] = function()
+						self.expanded = not self.expanded
+						self.motor:setGoal(Flipper.Spring.new((self.expanded and self.maxElementHeight or 0) + 30, {
+							frequency = 5,
+							dampingRatio = 1,
+						}))
+					end,
+				})
+				else nil,
+			Expansion = if props.changeList
+				then e(Expansion, {
+					rendered = self.state.renderExpansion,
+					indent = indent,
+					transparency = props.transparency,
+					changeList = props.changeList,
+					columnVisibility = props.columnVisibility,
+				})
+				else nil,
+			DiffIcon = if props.patchType
+				then e("ImageLabel", {
+					Image = Assets.Images.Diff[props.patchType],
+					ImageColor3 = theme.AddressEntry.PlaceholderColor,
+					ImageTransparency = props.transparency,
+					BackgroundTransparency = 1,
+					Size = UDim2.new(0, 20, 0, 20),
+					Position = UDim2.new(0, 0, 0, 15),
+					AnchorPoint = Vector2.new(0, 0.5),
+				})
+				else nil,
+			ClassIcon = e("ImageLabel", {
+				Image = iconProps.Image,
+				ImageTransparency = props.transparency,
+				ImageRectOffset = iconProps.ImageRectOffset,
+				ImageRectSize = iconProps.ImageRectSize,
+				BackgroundTransparency = 1,
+				Size = UDim2.new(0, 20, 0, 20),
+				Position = UDim2.new(0, indent, 0, 15),
+				AnchorPoint = Vector2.new(0, 0.5),
+			}),
+			InstanceName = e("TextLabel", {
+				Text = props.name .. (props.hint and string.format(
+					'  <font color="#%s">%s</font>',
+					theme.AddressEntry.PlaceholderColor:ToHex(),
+					props.hint
+				) or ""),
+				RichText = true,
+				BackgroundTransparency = 1,
+				Font = Enum.Font.GothamMedium,
+				TextSize = 14,
+				TextColor3 = theme.Settings.Setting.DescriptionColor,
+				TextXAlignment = Enum.TextXAlignment.Left,
+				TextTransparency = props.transparency,
+				TextTruncate = Enum.TextTruncate.AtEnd,
+				Size = UDim2.new(1, -indent - 50, 0, 30),
+				Position = UDim2.new(0, indent + 30, 0, 0),
+			}),
+			LineGuides = e("Folder", nil, lineGuides),
+		})
+	end)
+end
+
+return DomLabel

plugin/src/App/Components/PatchVisualizer/init.lua

@@ -0,0 +1,402 @@
+local HttpService = game:GetService("HttpService")
+
+local Rojo = script:FindFirstAncestor("Rojo")
+local Plugin = Rojo.Plugin
+local Packages = Rojo.Packages
+
+local Roact = require(Packages.Roact)
+local Log = require(Packages.Log)
+
+local PatchSet = require(Plugin.PatchSet)
+local decodeValue = require(Plugin.Reconciler.decodeValue)
+local getProperty = require(Plugin.Reconciler.getProperty)
+
+local BorderedContainer = require(Plugin.App.Components.BorderedContainer)
+local VirtualScroller = require(Plugin.App.Components.VirtualScroller)
+
+local e = Roact.createElement
+
+local function alphabeticalNext(t, state)
+	-- Equivalent of the next function, but returns the keys in the alphabetic
+	-- order of node names. We use a temporary ordered key table that is stored in the
+	-- table being iterated.
+
+	local key = nil
+	if state == nil then
+		-- First iteration, generate the index
+		local orderedIndex, i = table.create(5), 0
+		for k in t do
+			i += 1
+			orderedIndex[i] = k
+		end
+		table.sort(orderedIndex, function(a, b)
+			local nodeA, nodeB = t[a], t[b]
+			return (nodeA.name or "") < (nodeB.name or "")
+		end)
+
+		t.__orderedIndex = orderedIndex
+		key = orderedIndex[1]
+	else
+		-- Fetch the next value
+		for i, orderedState in t.__orderedIndex do
+			if orderedState == state then
+				key = t.__orderedIndex[i + 1]
+				break
+			end
+		end
+	end
+
+	if key then
+		return key, t[key]
+	end
+
+	-- No more value to return, cleanup
+	t.__orderedIndex = nil
+	return
+end
+
+local function alphabeticalPairs(t)
+	-- Equivalent of the pairs() iterator, but sorted
+	return alphabeticalNext, t, nil
+end
+
+local function Tree()
+	local tree = {
+		idToNode = {},
+		ROOT = {
+			className = "DataModel",
+			name = "ROOT",
+			children = {},
+		},
+	}
+	-- Add ROOT to idToNode or it won't be found by getNode since that searches *within* ROOT
+	tree.idToNode["ROOT"] = tree.ROOT
+
+	function tree:getNode(id, target)
+		if self.idToNode[id] then
+			return self.idToNode[id]
+		end
+
+		for nodeId, node in target or tree.ROOT.children do
+			if nodeId == id then
+				self.idToNode[id] = node
+				return node
+			end
+			local descendant = self:getNode(id, node.children)
+			if descendant then
+				return descendant
+			end
+		end
+
+		return nil
+	end
+
+	function tree:addNode(parent, props)
+		parent = parent or "ROOT"
+
+		local node = self:getNode(props.id)
+		if node then
+			for k, v in props do
+				node[k] = v
+			end
+			return node
+		end
+
+		node = table.clone(props)
+		node.children = {}
+
+		local parentNode = self:getNode(parent)
+		if not parentNode then
+			Log.warn("Failed to create node since parent doesnt exist: {}, {}", parent, props)
+			return
+		end
+
+		parentNode.children[node.id] = node
+		self.idToNode[node.id] = node
+
+		return node
+	end
+
+	function tree:buildAncestryNodes(ancestry, patch, instanceMap)
+		-- Build nodes for ancestry by going up the tree
+		local previousId = "ROOT"
+		for _, ancestorId in ancestry do
+			local value = instanceMap.fromIds[ancestorId] or patch.added[ancestorId]
+			if not value then
+				Log.warn("Failed to find ancestor object for " .. ancestorId)
+				continue
+			end
+			self:addNode(previousId, {
+				id = ancestorId,
+				className = value.ClassName,
+				name = value.Name,
+			})
+			previousId = ancestorId
+		end
+	end
+
+	return tree
+end
+
+local DomLabel = require(script.DomLabel)
+
+local PatchVisualizer = Roact.Component:extend("PatchVisualizer")
+
+function PatchVisualizer:init()
+	self.contentSize, self.setContentSize = Roact.createBinding(Vector2.new(0, 0))
+
+	self.updateEvent = Instance.new("BindableEvent")
+end
+
+function PatchVisualizer:willUnmount()
+	self.updateEvent:Destroy()
+end
+
+function PatchVisualizer:shouldUpdate(nextProps)
+	local currentPatch, nextPatch = self.props.patch, nextProps.patch
+
+	return not PatchSet.isEqual(currentPatch, nextPatch)
+end
+
+function PatchVisualizer:buildTree(patch, instanceMap)
+	local tree = Tree()
+
+	for _, change in patch.updated do
+		local instance = instanceMap.fromIds[change.id]
+		if not instance then
+			continue
+		end
+
+		-- Gather ancestors from existing DOM
+		local ancestry = {}
+		local parentObject = instance.Parent
+		local parentId = instanceMap.fromInstances[parentObject]
+		while parentObject do
+			table.insert(ancestry, 1, parentId)
+			parentObject = parentObject.Parent
+			parentId = instanceMap.fromInstances[parentObject]
+		end
+
+		tree:buildAncestryNodes(ancestry, patch, instanceMap)
+
+		-- Gather detail text
+		local changeList, hint = nil, nil
+		if next(change.changedProperties) or change.changedName then
+			changeList = {}
+
+			local hintBuffer, i = {}, 0
+			local function addProp(prop: string, current: any?, incoming: any?)
+				i += 1
+				hintBuffer[i] = prop
+				changeList[i] = { prop, current, incoming }
+			end
+
+			-- Gather the changes
+
+			if change.changedName then
+				addProp("Name", instance.Name, change.changedName)
+			end
+
+			for prop, incoming in change.changedProperties do
+				local incomingSuccess, incomingValue = decodeValue(incoming, instanceMap)
+				local currentSuccess, currentValue = getProperty(instance, prop)
+
+				addProp(
+					prop,
+					if currentSuccess then currentValue else "[Error]",
+					if incomingSuccess then incomingValue else next(incoming)
+				)
+			end
+
+			-- Finalize detail values
+
+			-- Trim hint to top 3
+			table.sort(hintBuffer)
+			if #hintBuffer > 3 then
+				hintBuffer = {
+					hintBuffer[1],
+					hintBuffer[2],
+					hintBuffer[3],
+					i - 3 .. " more",
+				}
+			end
+			hint = table.concat(hintBuffer, ", ")
+
+			-- Sort changes and add header
+			table.sort(changeList, function(a, b)
+				return a[1] < b[1]
+			end)
+			table.insert(changeList, 1, { "Property", "Current", "Incoming" })
+		end
+
+		-- Add this node to tree
+		tree:addNode(instanceMap.fromInstances[instance.Parent], {
+			id = change.id,
+			patchType = "Edit",
+			className = instance.ClassName,
+			name = instance.Name,
+			hint = hint,
+			changeList = changeList,
+		})
+	end
+
+	for _, instance in patch.removed do
+		-- Gather ancestors from existing DOM
+		-- (note that they may have no ID if they're being removed as unknown)
+		local ancestry = {}
+		local parentObject = instance.Parent
+		local parentId = instanceMap.fromInstances[parentObject] or HttpService:GenerateGUID(false)
+		while parentObject do
+			instanceMap:insert(parentId, parentObject)
+			table.insert(ancestry, 1, parentId)
+			parentObject = parentObject.Parent
+			parentId = instanceMap.fromInstances[parentObject] or HttpService:GenerateGUID(false)
+		end
+
+		tree:buildAncestryNodes(ancestry, patch, instanceMap)
+
+		-- Add this node to tree
+		local nodeId = instanceMap.fromInstances[instance] or HttpService:GenerateGUID(false)
+		instanceMap:insert(nodeId, instance)
+		tree:addNode(instanceMap.fromInstances[instance.Parent], {
+			id = nodeId,
+			patchType = "Remove",
+			className = instance.ClassName,
+			name = instance.Name,
+		})
+	end
+
+	for _, change in patch.added do
+		-- Gather ancestors from existing DOM or future additions
+		local ancestry = {}
+		local parentId = change.Parent
+		local parentData = patch.added[parentId]
+		local parentObject = instanceMap.fromIds[parentId]
+		while parentId do
+			table.insert(ancestry, 1, parentId)
+			parentId = nil
+
+			if parentData then
+				parentId = parentData.Parent
+				parentData = patch.added[parentId]
+				parentObject = instanceMap.fromIds[parentId]
+			elseif parentObject then
+				parentObject = parentObject.Parent
+				parentId = instanceMap.fromInstances[parentObject]
+				parentData = patch.added[parentId]
+			end
+		end
+
+		tree:buildAncestryNodes(ancestry, patch, instanceMap)
+
+		-- Gather detail text
+		local changeList, hint = nil, nil
+		if next(change.Properties) then
+			changeList = {}
+
+			local hintBuffer, i = {}, 0
+			for prop, incoming in change.Properties do
+				i += 1
+				hintBuffer[i] = prop
+
+				local success, incomingValue = decodeValue(incoming, instanceMap)
+				if success then
+					table.insert(changeList, { prop, "N/A", incomingValue })
+				else
+					table.insert(changeList, { prop, "N/A", next(incoming) })
+				end
+			end
+
+			-- Finalize detail values
+
+			-- Trim hint to top 3
+			table.sort(hintBuffer)
+			if #hintBuffer > 3 then
+				hintBuffer = {
+					hintBuffer[1],
+					hintBuffer[2],
+					hintBuffer[3],
+					i - 3 .. " more",
+				}
+			end
+			hint = table.concat(hintBuffer, ", ")
+
+			-- Sort changes and add header
+			table.sort(changeList, function(a, b)
+				return a[1] < b[1]
+			end)
+			table.insert(changeList, 1, { "Property", "Current", "Incoming" })
+		end
+
+		-- Add this node to tree
+		tree:addNode(change.Parent, {
+			id = change.Id,
+			patchType = "Add",
+			className = change.ClassName,
+			name = change.Name,
+			hint = hint,
+			changeList = changeList,
+		})
+	end
+
+	return tree
+end
+
+function PatchVisualizer:render()
+	local patch = self.props.patch
+	local instanceMap = self.props.instanceMap
+
+	local tree = self:buildTree(patch, instanceMap)
+
+	-- Recusively draw tree
+	local scrollElements, elementHeights = {}, {}
+	local function drawNode(node, depth)
+		local elementHeight, setElementHeight = Roact.createBinding(30)
+		table.insert(elementHeights, elementHeight)
+		table.insert(
+			scrollElements,
+			e(DomLabel, {
+				columnVisibility = self.props.columnVisibility,
+				updateEvent = self.updateEvent,
+				elementHeight = elementHeight,
+				setElementHeight = setElementHeight,
+				patchType = node.patchType,
+				className = node.className,
+				name = node.name,
+				hint = node.hint,
+				changeList = node.changeList,
+				depth = depth,
+				transparency = self.props.transparency,
+			})
+		)
+
+		for _, childNode in alphabeticalPairs(node.children) do
+			drawNode(childNode, depth + 1)
+		end
+	end
+	for _, node in alphabeticalPairs(tree.ROOT.children) do
+		drawNode(node, 0)
+	end
+
+	return e(BorderedContainer, {
+		transparency = self.props.transparency,
+		size = self.props.size,
+		position = self.props.position,
+		layoutOrder = self.props.layoutOrder,
+	}, {
+		VirtualScroller = e(VirtualScroller, {
+			size = UDim2.new(1, 0, 1, 0),
+			transparency = self.props.transparency,
+			count = #scrollElements,
+			updateEvent = self.updateEvent.Event,
+			render = function(i)
+				return scrollElements[i]
+			end,
+			getHeightBinding = function(i)
+				return elementHeights[i]
+			end,
+		}),
+	})
+end
+
+return PatchVisualizer

plugin/src/App/Components/Studio/StudioPluginGui.lua

@@ -5,6 +5,7 @@ local Packages = Rojo.Packages
 local Roact = require(Packages.Roact)
 
 local Dictionary = require(Plugin.Dictionary)
+local Theme = require(Plugin.App.Theme)
 
 local StudioPluginContext = require(script.Parent.StudioPluginContext)
 
@@ -29,8 +30,10 @@ function StudioPluginGui:init()
 		self.props.initDockState,
 		self.props.active,
 		self.props.overridePreviousState,
-		floatingSize.X, floatingSize.Y,
-		minimumSize.X, minimumSize.Y
+		floatingSize.X,
+		floatingSize.Y,
+		minimumSize.X,
+		minimumSize.Y
 	)
 
 	local pluginGui = self.props.plugin:CreateDockWidgetPluginGui(self.props.id, dockWidgetPluginGuiInfo)
@@ -57,7 +60,16 @@ end
 function StudioPluginGui:render()
 	return e(Roact.Portal, {
 		target = self.pluginGui,
-	}, self.props[Roact.Children])
+	}, {
+		Background = Theme.with(function(theme)
+			return e("Frame", {
+				Size = UDim2.new(1, 0, 1, 0),
+				BackgroundColor3 = theme.BackgroundColor,
+				ZIndex = 0,
+				BorderSizePixel = 0,
+			}, self.props[Roact.Children])
+		end),
+	})
 end
 
 function StudioPluginGui:didUpdate(lastProps)
@@ -75,9 +87,12 @@ end
 local function StudioPluginGuiWrapper(props)
 	return e(StudioPluginContext.Consumer, {
 		render = function(plugin)
-			return e(StudioPluginGui, Dictionary.merge(props, {
-				plugin = plugin,
-			}))
+			return e(
+				StudioPluginGui,
+				Dictionary.merge(props, {
+					plugin = plugin,
+				})
+			)
 		end,
 	})
 end

plugin/src/App/Components/Tooltip.lua

@@ -23,7 +23,7 @@ local TooltipContext = Roact.createContext({})
 local function Popup(props)
 	local textSize = TextService:GetTextSize(
 		props.Text, 16, Enum.Font.GothamMedium, Vector2.new(math.min(props.parentSize.X, 160), math.huge)
-	) + TEXT_PADDING
+	) + TEXT_PADDING + (Vector2.one * 2)
 
 	local trigger = props.Trigger:getValue()
 
@@ -68,12 +68,12 @@ local function Popup(props)
 					if displayAbove then
 						UDim2.new(
 							0, math.clamp(props.Position.X - X, 6, textSize.X-6),
-							1, -3
+							1, -1
 						)
 					else
 						UDim2.new(
 							0, math.clamp(props.Position.X - X, 6, textSize.X-6),
-							0, -TAIL_SIZE+3
+							0, -TAIL_SIZE+1
 						),
 				Size = UDim2.fromOffset(TAIL_SIZE, TAIL_SIZE),
 				AnchorPoint = Vector2.new(0.5, 0),

plugin/src/App/Components/VirtualScroller.lua

@@ -0,0 +1,156 @@
+local Rojo = script:FindFirstAncestor("Rojo")
+local Plugin = Rojo.Plugin
+local Packages = Rojo.Packages
+
+local Roact = require(Packages.Roact)
+
+local Assets = require(Plugin.Assets)
+local Theme = require(Plugin.App.Theme)
+local bindingUtil = require(Plugin.App.bindingUtil)
+
+local e = Roact.createElement
+
+local VirtualScroller = Roact.Component:extend("VirtualScroller")
+
+function VirtualScroller:init()
+	self.scrollFrameRef = Roact.createRef()
+	self:setState({
+		WindowSize = Vector2.new(),
+		CanvasPosition = Vector2.new(),
+	})
+
+	self.totalCanvas, self.setTotalCanvas = Roact.createBinding(0)
+	self.padding, self.setPadding = Roact.createBinding(0)
+
+	self:refresh()
+	if self.props.updateEvent then
+		self.connection = self.props.updateEvent:Connect(function()
+			self:refresh()
+		end)
+	end
+end
+
+function VirtualScroller:didMount()
+	local rbx = self.scrollFrameRef:getValue()
+
+	local windowSizeSignal = rbx:GetPropertyChangedSignal("AbsoluteWindowSize")
+	self.windowSizeChanged = windowSizeSignal:Connect(function()
+		self:setState({ WindowSize = rbx.AbsoluteWindowSize })
+		self:refresh()
+	end)
+
+	local canvasPositionSignal = rbx:GetPropertyChangedSignal("CanvasPosition")
+	self.canvasPositionChanged = canvasPositionSignal:Connect(function()
+		if math.abs(rbx.CanvasPosition.Y - self.state.CanvasPosition.Y) > 5 then
+			self:setState({ CanvasPosition = rbx.CanvasPosition })
+			self:refresh()
+		end
+	end)
+
+	self:refresh()
+end
+
+function VirtualScroller:willUnmount()
+	self.windowSizeChanged:Disconnect()
+	self.canvasPositionChanged:Disconnect()
+	if self.connection then
+		self.connection:Disconnect()
+		self.connection = nil
+	end
+end
+
+function VirtualScroller:refresh()
+	local props = self.props
+	local state = self.state
+
+	local count = props.count
+	local windowSize, canvasPosition = state.WindowSize.Y, state.CanvasPosition.Y
+	local bottom = canvasPosition + windowSize
+
+	local minIndex, maxIndex = 1, count
+	local padding, canvasSize = 0, 0
+
+	local pos = 0
+	for i = 1, count do
+		local height = props.getHeightBinding(i):getValue()
+		canvasSize += height
+
+		if pos > bottom then
+			-- Below window
+			if maxIndex > i then
+				maxIndex = i
+			end
+		end
+
+		pos += height
+
+		if pos < canvasPosition then
+			-- Above window
+			minIndex = i
+			padding = pos - height
+		end
+	end
+
+	self.setPadding(padding)
+	self.setTotalCanvas(canvasSize)
+	self:setState({
+		Start = minIndex,
+		End = maxIndex,
+	})
+end
+
+function VirtualScroller:render()
+	local props, state = self.props, self.state
+
+	local items = {}
+	for i = state.Start, state.End do
+		items["Item" .. i] = e("Frame", {
+			LayoutOrder = i,
+			Size = props.getHeightBinding(i):map(function(height)
+				return UDim2.new(1, 0, 0, height)
+			end),
+			BackgroundTransparency = 1,
+		}, props.render(i))
+	end
+
+	return Theme.with(function(theme)
+		return e("ScrollingFrame", {
+			Size = props.size,
+			Position = props.position,
+			AnchorPoint = props.anchorPoint,
+			BackgroundTransparency = props.backgroundTransparency or 1,
+			BackgroundColor3 = props.backgroundColor3,
+			BorderColor3 = props.borderColor3,
+			CanvasSize = self.totalCanvas:map(function(s)
+				return UDim2.fromOffset(0, s)
+			end),
+			ScrollBarThickness = 9,
+			ScrollBarImageColor3 = theme.ScrollBarColor,
+			ScrollBarImageTransparency = props.transparency:map(function(value)
+				return bindingUtil.blendAlpha({ 0.65, value })
+			end),
+			TopImage = Assets.Images.ScrollBar.Top,
+			MidImage = Assets.Images.ScrollBar.Middle,
+			BottomImage = Assets.Images.ScrollBar.Bottom,
+
+			ElasticBehavior = Enum.ElasticBehavior.Always,
+			ScrollingDirection = Enum.ScrollingDirection.Y,
+			VerticalScrollBarInset = Enum.ScrollBarInset.ScrollBar,
+			[Roact.Ref] = self.scrollFrameRef,
+		}, {
+			Layout = e("UIListLayout", {
+				Padding = UDim.new(0, 0),
+				SortOrder = Enum.SortOrder.LayoutOrder,
+				FillDirection = Enum.FillDirection.Vertical,
+			}),
+			Padding = e("UIPadding", {
+				PaddingTop = self.padding:map(function(p)
+					return UDim.new(0, p)
+				end),
+			}),
+			Content = Roact.createFragment(items),
+		})
+	end)
+end
+
+return VirtualScroller

plugin/src/App/StatusPages/Confirming.lua

@@ -0,0 +1,156 @@
+local TextService = game:GetService("TextService")
+
+local Rojo = script:FindFirstAncestor("Rojo")
+local Plugin = Rojo.Plugin
+local Packages = Rojo.Packages
+
+local Roact = require(Packages.Roact)
+
+local Settings = require(Plugin.Settings)
+local Theme = require(Plugin.App.Theme)
+local TextButton = require(Plugin.App.Components.TextButton)
+local Header = require(Plugin.App.Components.Header)
+local StudioPluginGui = require(Plugin.App.Components.Studio.StudioPluginGui)
+local Tooltip = require(Plugin.App.Components.Tooltip)
+local PatchVisualizer = require(Plugin.App.Components.PatchVisualizer)
+
+local e = Roact.createElement
+
+local ConfirmingPage = Roact.Component:extend("ConfirmingPage")
+
+function ConfirmingPage:init()
+	self.contentSize, self.setContentSize = Roact.createBinding(0)
+	self.containerSize, self.setContainerSize = Roact.createBinding(Vector2.new(0, 0))
+end
+
+function ConfirmingPage:render()
+	return Theme.with(function(theme)
+		local pageContent = Roact.createFragment({
+			Header = e(Header, {
+				transparency = self.props.transparency,
+				layoutOrder = 1,
+			}),
+
+			Title = e("TextLabel", {
+				Text = string.format(
+					"Sync changes for project '%s':",
+					self.props.confirmData.serverInfo.projectName or "UNKNOWN"
+				),
+				LayoutOrder = 2,
+				Font = Enum.Font.Gotham,
+				LineHeight = 1.2,
+				TextSize = 14,
+				TextColor3 = theme.Settings.Setting.DescriptionColor,
+				TextXAlignment = Enum.TextXAlignment.Left,
+				TextTransparency = self.props.transparency,
+				Size = UDim2.new(1, 0, 0, 20),
+				BackgroundTransparency = 1,
+			}),
+
+			PatchVisualizer = e(PatchVisualizer, {
+				size = UDim2.new(1, 0, 1, -150),
+				transparency = self.props.transparency,
+				layoutOrder = 3,
+
+				columnVisibility = {true, true, true},
+				patch = self.props.confirmData.patch,
+				instanceMap = self.props.confirmData.instanceMap,
+			}),
+
+			Buttons = e("Frame", {
+				Size = UDim2.new(1, 0, 0, 34),
+				LayoutOrder = 4,
+				BackgroundTransparency = 1,
+			}, {
+				Abort = e(TextButton, {
+					text = "Abort",
+					style = "Bordered",
+					transparency = self.props.transparency,
+					layoutOrder = 1,
+					onClick = self.props.onAbort,
+				}, {
+					Tip = e(Tooltip.Trigger, {
+						text = "Stop the connection process"
+					}),
+				}),
+
+				Reject = if Settings:get("twoWaySync")
+					then e(TextButton, {
+						text = "Reject",
+						style = "Bordered",
+						transparency = self.props.transparency,
+						layoutOrder = 2,
+						onClick = self.props.onReject,
+					}, {
+						Tip = e(Tooltip.Trigger, {
+							text = "Push Studio changes to the Rojo server"
+						}),
+					})
+					else nil,
+
+				Accept = e(TextButton, {
+					text = "Accept",
+					style = "Solid",
+					transparency = self.props.transparency,
+					layoutOrder = 3,
+					onClick = self.props.onAccept,
+				}, {
+					Tip = e(Tooltip.Trigger, {
+						text = "Pull Rojo server changes to Studio"
+					}),
+				}),
+
+				Layout = e("UIListLayout", {
+					HorizontalAlignment = Enum.HorizontalAlignment.Right,
+					FillDirection = Enum.FillDirection.Horizontal,
+					SortOrder = Enum.SortOrder.LayoutOrder,
+					Padding = UDim.new(0, 10),
+				}),
+			}),
+
+			Layout = e("UIListLayout", {
+				HorizontalAlignment = Enum.HorizontalAlignment.Center,
+				VerticalAlignment = Enum.VerticalAlignment.Center,
+				FillDirection = Enum.FillDirection.Vertical,
+				SortOrder = Enum.SortOrder.LayoutOrder,
+				Padding = UDim.new(0, 10),
+			}),
+
+			Padding = e("UIPadding", {
+				PaddingLeft = UDim.new(0, 20),
+				PaddingRight = UDim.new(0, 20),
+			}),
+		})
+
+		if self.props.createPopup then
+			return e(StudioPluginGui, {
+				id = "Rojo_DiffSync",
+				title = string.format(
+					"Confirm sync for project '%s':",
+					self.props.confirmData.serverInfo.projectName or "UNKNOWN"
+				),
+				active = true,
+
+				initDockState = Enum.InitialDockState.Float,
+				initEnabled = true,
+				overridePreviousState = true,
+				floatingSize = Vector2.new(500, 350),
+				minimumSize = Vector2.new(400, 250),
+
+				zIndexBehavior = Enum.ZIndexBehavior.Sibling,
+
+				onClose = self.props.onAbort,
+			}, {
+				Tooltips = e(Tooltip.Container, nil),
+				Content = e("Frame", {
+					Size = UDim2.fromScale(1, 1),
+					BackgroundTransparency = 1,
+				}, pageContent),
+			})
+		end
+
+		return pageContent
+	end)
+end
+
+return ConfirmingPage

plugin/src/App/StatusPages/Connected.lua

@@ -3,14 +3,18 @@ local Plugin = Rojo.Plugin
 local Packages = Rojo.Packages
 
 local Roact = require(Packages.Roact)
+local Flipper = require(Packages.Flipper)
 
+local bindingUtil = require(Plugin.App.bindingUtil)
 local Theme = require(Plugin.App.Theme)
 local Assets = require(Plugin.Assets)
+local PatchSet = require(Plugin.PatchSet)
 
 local Header = require(Plugin.App.Components.Header)
 local IconButton = require(Plugin.App.Components.IconButton)
 local BorderedContainer = require(Plugin.App.Components.BorderedContainer)
 local Tooltip = require(Plugin.App.Components.Tooltip)
+local PatchVisualizer = require(Plugin.App.Components.PatchVisualizer)
 
 local e = Roact.createElement
 
@@ -34,6 +38,50 @@ function timeSinceText(elapsed: number): string
 	return ageText
 end
 
+local function ChangesDrawer(props)
+	if props.rendered == false then
+		return nil
+	end
+
+	return Theme.with(function(theme)
+		return e(BorderedContainer, {
+			transparency = props.transparency,
+			size = props.height:map(function(y)
+				return UDim2.new(1, 0, y, -180 * y)
+			end),
+			position = UDim2.new(0, 0, 1, 0),
+			anchorPoint = Vector2.new(0, 1),
+			layoutOrder = props.layoutOrder,
+		}, {
+			Close = e(IconButton, {
+				icon = Assets.Images.Icons.Close,
+				iconSize = 24,
+				color = theme.ConnectionDetails.DisconnectColor,
+				transparency = props.transparency,
+
+				position = UDim2.new(1, 0, 0, 0),
+				anchorPoint = Vector2.new(1, 0),
+
+				onClick = props.onClose,
+			}, {
+				Tip = e(Tooltip.Trigger, {
+					text = "Close the patch visualizer"
+				}),
+			}),
+
+			PatchVisualizer = e(PatchVisualizer, {
+				size = UDim2.new(1, 0, 1, 0),
+				transparency = props.transparency,
+				layoutOrder = 3,
+
+				columnVisibility = {true, false, true},
+				patch = props.patchInfo:getValue().patch,
+				instanceMap = props.serveSession.__instanceMap,
+			}),
+		})
+	end)
+end
+
 local function ConnectionDetails(props)
 	return Theme.with(function(theme)
 		return e(BorderedContainer, {
@@ -107,9 +155,44 @@ end
 
 local ConnectedPage = Roact.Component:extend("ConnectedPage")
 
+function ConnectedPage:init()
+	self.changeDrawerMotor = Flipper.SingleMotor.new(0)
+	self.changeDrawerHeight = bindingUtil.fromMotor(self.changeDrawerMotor)
+
+	self.changeDrawerMotor:onStep(function(value)
+		local renderChanges = value > 0.05
+
+		self:setState(function(state)
+			if state.renderChanges == renderChanges then
+				return nil
+			end
+
+			return {
+				renderChanges = renderChanges,
+			}
+		end)
+	end)
+
+	self:setState({
+		renderChanges = false,
+	})
+end
+
 function ConnectedPage:render()
 	return Theme.with(function(theme)
 		return Roact.createFragment({
+			Padding = e("UIPadding", {
+				PaddingLeft = UDim.new(0, 20),
+				PaddingRight = UDim.new(0, 20),
+			}),
+
+			Layout = e("UIListLayout", {
+				VerticalAlignment = Enum.VerticalAlignment.Center,
+				FillDirection = Enum.FillDirection.Vertical,
+				SortOrder = Enum.SortOrder.LayoutOrder,
+				Padding = UDim.new(0, 10),
+			}),
+
 			Header = e(Header, {
 				transparency = self.props.transparency,
 				layoutOrder = 1,
@@ -124,12 +207,13 @@ function ConnectedPage:render()
 				onDisconnect = self.props.onDisconnect,
 			}),
 
-			Info = e("TextLabel", {
+			ChangeInfo = e("TextButton", {
 				Text = self.props.patchInfo:map(function(info)
+					local changes = PatchSet.countChanges(info.patch)
 					return string.format(
 						"<i>Synced %d change%s %s</i>",
-						info.changes,
-						info.changes == 1 and "" or "s",
+						changes,
+						changes == 1 and "" or "s",
 						timeSinceText(os.time() - info.timestamp)
 					)
 				end),
@@ -146,18 +230,36 @@ function ConnectedPage:render()
 
 				LayoutOrder = 3,
 				BackgroundTransparency = 1,
+
+				[Roact.Event.Activated] = function()
+					if self.state.renderChanges then
+						self.changeDrawerMotor:setGoal(Flipper.Spring.new(0, {
+							frequency = 4,
+							dampingRatio = 1,
+						}))
+					else
+						self.changeDrawerMotor:setGoal(Flipper.Spring.new(1, {
+							frequency = 3,
+							dampingRatio = 1,
+						}))
+					end
+				end,
 			}),
 
-			Layout = e("UIListLayout", {
-				VerticalAlignment = Enum.VerticalAlignment.Center,
-				FillDirection = Enum.FillDirection.Vertical,
-				SortOrder = Enum.SortOrder.LayoutOrder,
-				Padding = UDim.new(0, 10),
-			}),
+			ChangesDrawer = e(ChangesDrawer, {
+				rendered = self.state.renderChanges,
+				transparency = self.props.transparency,
+				patchInfo = self.props.patchInfo,
+				serveSession = self.props.serveSession,
+				height = self.changeDrawerHeight,
+				layoutOrder = 4,
 
-			Padding = e("UIPadding", {
-				PaddingLeft = UDim.new(0, 20),
-				PaddingRight = UDim.new(0, 20),
+				onClose = function()
+					self.changeDrawerMotor:setGoal(Flipper.Spring.new(0, {
+						frequency = 4,
+						dampingRatio = 1,
+					}))
+				end,
 			}),
 		})
 	end)

plugin/src/App/StatusPages/NotConnected.lua

@@ -110,6 +110,7 @@ function NotConnectedPage:render()
 			Size = UDim2.new(1, 0, 0, 34),
 			LayoutOrder = 3,
 			BackgroundTransparency = 1,
+			ZIndex = 2,
 		}, {
 			Settings = e(TextButton, {
 				text = "Settings",

plugin/src/App/StatusPages/init.lua

@@ -2,6 +2,7 @@ return {
 	NotConnected = require(script.NotConnected),
 	Settings = require(script.Settings),
 	Connecting = require(script.Connecting),
+	Confirming = require(script.Confirming),
 	Connected = require(script.Connected),
 	Error = require(script.Error),
-}
+}

plugin/src/App/Theme.lua

@@ -95,6 +95,12 @@ local lightTheme = strict("LightTheme", {
 		ForegroundColor = BRAND_COLOR,
 		BackgroundColor = hexColor(0xEEEEEE),
 	},
+	Diff = {
+		Add = hexColor(0xbaffbd),
+		Remove = hexColor(0xffbdba),
+		Edit = hexColor(0xbacdff),
+		Row = hexColor(0x000000),
+	},
 	ConnectionDetails = {
 		ProjectNameColor = hexColor(0x00000),
 		AddressColor = hexColor(0x00000),
@@ -184,6 +190,12 @@ local darkTheme = strict("DarkTheme", {
 		ForegroundColor = BRAND_COLOR,
 		BackgroundColor = hexColor(0x2B2B2B),
 	},
+	Diff = {
+		Add = hexColor(0x273732),
+		Remove = hexColor(0x3F2D32),
+		Edit = hexColor(0x193345),
+		Row = hexColor(0xFFFFFF),
+	},
 	ConnectionDetails = {
 		ProjectNameColor = hexColor(0xFFFFFF),
 		AddressColor = hexColor(0xFFFFFF),

plugin/src/App/init.lua

@@ -16,6 +16,7 @@ local strict = require(Plugin.strict)
 local Dictionary = require(Plugin.Dictionary)
 local ServeSession = require(Plugin.ServeSession)
 local ApiContext = require(Plugin.ApiContext)
+local PatchSet = require(Plugin.PatchSet)
 local preloadAssets = require(Plugin.preloadAssets)
 local soundPlayer = require(Plugin.soundPlayer)
 local Theme = require(script.Theme)
@@ -34,6 +35,7 @@ local AppStatus = strict("AppStatus", {
 	NotConnected = "NotConnected",
 	Settings = "Settings",
 	Connecting = "Connecting",
+	Confirming = "Confirming",
 	Connected = "Connected",
 	Error = "Error",
 })
@@ -50,13 +52,16 @@ function App:init()
 	self.port, self.setPort = Roact.createBinding(priorPort or "")
 
 	self.patchInfo, self.setPatchInfo = Roact.createBinding({
-		changes = 0,
+		patch = PatchSet.newEmpty(),
 		timestamp = os.time(),
 	})
+	self.confirmationBindable = Instance.new("BindableEvent")
+	self.confirmationEvent = self.confirmationBindable.Event
 
 	self:setState({
 		appStatus = AppStatus.NotConnected,
 		guiEnabled = false,
+		confirmData = {},
 		notifications = {},
 		toolbarIcon = Assets.Images.PluginButton,
 	})
@@ -214,32 +219,31 @@ function App:startSession()
 		twoWaySync = sessionOptions.twoWaySync,
 	})
 
-	serveSession:onPatchApplied(function(patch, unapplied)
+	serveSession:onPatchApplied(function(patch, _unapplied)
+		if PatchSet.isEmpty(patch) then
+			-- Ignore empty patches
+			return
+		end
+
 		local now = os.time()
-		local changes = 0
-
-		for _, set in patch do
-			for _ in set do
-				changes += 1
-			end
-		end
-		for _, set in unapplied do
-			for _ in set do
-				changes -= 1
-			end
-		end
-
-		if changes == 0 then return end
 
 		local old = self.patchInfo:getValue()
 		if now - old.timestamp < 2 then
-			changes += old.changes
-		end
+			-- Patches that apply in the same second are
+			-- considered to be part of the same change for human clarity
+			local merged = PatchSet.newEmpty()
+			PatchSet.assign(merged, old.patch, patch)
 
-		self.setPatchInfo({
-			changes = changes,
-			timestamp = now,
-		})
+			self.setPatchInfo({
+				patch = merged,
+				timestamp = now,
+			})
+		else
+			self.setPatchInfo({
+				patch = patch,
+				timestamp = now,
+			})
+		end
 	end)
 
 	serveSession:onStatusChanged(function(status, details)
@@ -285,6 +289,32 @@ function App:startSession()
 		end
 	end)
 
+	serveSession:setConfirmCallback(function(instanceMap, patch, serverInfo)
+		if PatchSet.isEmpty(patch) then
+			return "Accept"
+		end
+
+		self:setState({
+			appStatus = AppStatus.Confirming,
+			confirmData = {
+				instanceMap = instanceMap,
+				patch = patch,
+				serverInfo = serverInfo,
+			},
+			toolbarIcon = Assets.Images.PluginButton,
+		})
+
+		self:addNotification(
+			string.format(
+				"Please accept%sor abort the initializing sync session.",
+				Settings:get("twoWaySync") and ", reject, " or " "
+			),
+			7
+		)
+
+		return self.confirmationEvent:Wait()
+	end)
+
 	serveSession:start()
 
 	self.serveSession = serveSession
@@ -295,7 +325,7 @@ function App:startSession()
 			local patchInfo = table.clone(self.patchInfo:getValue())
 			self.setPatchInfo(patchInfo)
 			local elapsed = os.time() - patchInfo.timestamp
-			task.wait(elapsed < 60 and 1 or elapsed/5)
+			task.wait(elapsed < 60 and 1 or elapsed / 5)
 		end
 	end)
 end
@@ -379,12 +409,28 @@ function App:render()
 						end,
 					}),
 
+					ConfirmingPage = createPageElement(AppStatus.Confirming, {
+						confirmData = self.state.confirmData,
+						createPopup = not self.state.guiEnabled,
+
+						onAbort = function()
+							self.confirmationBindable:Fire("Abort")
+						end,
+						onAccept = function()
+							self.confirmationBindable:Fire("Accept")
+						end,
+						onReject = function()
+							self.confirmationBindable:Fire("Reject")
+						end,
+					}),
+
 					Connecting = createPageElement(AppStatus.Connecting),
 
 					Connected = createPageElement(AppStatus.Connected, {
 						projectName = self.state.projectName,
 						address = self.state.address,
 						patchInfo = self.patchInfo,
+						serveSession = self.serveSession,
 
 						onDisconnect = function()
 							self:endSession()
@@ -409,15 +455,6 @@ function App:render()
 							})
 						end,
 					}),
-
-					Background = Theme.with(function(theme)
-						return e("Frame", {
-							Size = UDim2.new(1, 0, 1, 0),
-							BackgroundColor3 = theme.BackgroundColor,
-							ZIndex = 0,
-							BorderSizePixel = 0,
-						})
-					end),
 				}),
 
 				RojoNotifications = e("ScreenGui", {}, {
@@ -428,10 +465,10 @@ function App:render()
 						Padding = UDim.new(0, 5),
 					}),
 					padding = e("UIPadding", {
-						PaddingTop = UDim.new(0, 5);
-						PaddingBottom = UDim.new(0, 5);
-						PaddingLeft = UDim.new(0, 5);
-						PaddingRight = UDim.new(0, 5);
+						PaddingTop = UDim.new(0, 5),
+						PaddingBottom = UDim.new(0, 5),
+						PaddingLeft = UDim.new(0, 5),
+						PaddingRight = UDim.new(0, 5),
 					}),
 					notifs = e(Notifications, {
 						soundPlayer = self.props.soundPlayer,
@@ -452,7 +489,9 @@ function App:render()
 				onTriggered = function()
 					if self.serveSession == nil or self.serveSession:getStatus() == ServeSession.Status.NotStarted then
 						self:startSession()
-					elseif self.serveSession ~= nil and self.serveSession:getStatus() == ServeSession.Status.Connected then
+					elseif
+						self.serveSession ~= nil and self.serveSession:getStatus() == ServeSession.Status.Connected
+					then
 						self:endSession()
 					end
 				end,
@@ -500,7 +539,7 @@ function App:render()
 							}
 						end)
 					end,
-				})
+				}),
 			}),
 		}),
 	})

plugin/src/Assets.lua

@@ -25,6 +25,11 @@ local Assets = {
 			Back = "rbxassetid://6017213752",
 			Reset = "rbxassetid://10142422327",
 		},
+		Diff = {
+			Add = "rbxassetid://10434145835",
+			Remove = "rbxassetid://10434408368",
+			Edit = "rbxassetid://10434144680",
+		},
 		Checkbox = {
 			Active = "rbxassetid://6016251644",
 			Inactive = "rbxassetid://6016251963",

plugin/src/PatchSet.lua

@@ -8,6 +8,40 @@ local t = require(Packages.t)
 
 local Types = require(script.Parent.Types)
 
+local function deepEqual(a: any, b: any): boolean
+	local typeA = typeof(a)
+	if typeA ~= typeof(b) then
+		return false
+	end
+
+	if typeof(a) == "table" then
+		local checkedKeys = {}
+
+		for key, value in a do
+			checkedKeys[key] = true
+
+			if deepEqual(value, b[key]) == false then
+				return false
+			end
+		end
+
+		for key, value in b do
+			if checkedKeys[key] then continue end
+			if deepEqual(value, a[key]) == false then
+				return false
+			end
+		end
+
+		return true
+	end
+
+	if a == b then
+		return true
+	end
+
+	return false
+end
+
 local PatchSet = {}
 
 PatchSet.validate = t.interface({
@@ -57,6 +91,32 @@ function PatchSet.hasUpdates(patchSet)
 	return next(patchSet.updated) ~= nil
 end
 
+--[[
+	Tells whether the given PatchSets are equal.
+]]
+function PatchSet.isEqual(patchA, patchB)
+	return deepEqual(patchA, patchB)
+end
+
+--[[
+	Count the number of changes in the given PatchSet.
+]]
+function PatchSet.countChanges(patch)
+	local count = 0
+
+	for _ in patch.added do
+		count += 1
+	end
+	for _ in patch.removed do
+		count += 1
+	end
+	for _ in patch.updated do
+		count += 1
+	end
+
+	return count
+end
+
 --[[
 	Merge multiple PatchSet objects into the given PatchSet.
 ]]

plugin/src/Reconciler/diff.lua

@@ -15,6 +15,86 @@ local function isEmpty(table)
 	return next(table) == nil
 end
 
+local function fuzzyEq(a: number, b: number, epsilon: number): boolean
+	return math.abs(a - b) < epsilon
+end
+
+local function trueEquals(a, b): boolean
+	-- Exit early for simple equality values
+	if a == b then
+		return true
+	end
+
+	local typeA, typeB = typeof(a), typeof(b)
+
+	-- For tables, try recursive deep equality
+	if typeA == "table" and typeB == "table" then
+		local checkedKeys = {}
+		for key, value in pairs(a) do
+			checkedKeys[key] = true
+			if not trueEquals(value, b[key]) then
+				return false
+			end
+		end
+		for key, value in pairs(b) do
+			if checkedKeys[key] then continue end
+			if not trueEquals(value, a[key]) then
+				return false
+			end
+		end
+		return true
+
+	-- For numbers, compare with epsilon of 0.0001 to avoid floating point inequality
+	elseif typeA == "number" and typeB == "number" then
+		return fuzzyEq(a, b, 0.0001)
+
+	-- For EnumItem->number, compare the EnumItem's value
+	elseif typeA == "number" and typeB == "EnumItem" then
+		return a == b.Value
+	elseif typeA == "EnumItem" and typeB == "number" then
+		return a.Value == b
+
+	-- For Color3s, compare to RGB ints to avoid floating point inequality
+	elseif typeA == "Color3" and typeB == "Color3" then
+		local aR, aG, aB = math.floor(a.R * 255), math.floor(a.G * 255), math.floor(a.B * 255)
+		local bR, bG, bB = math.floor(b.R * 255), math.floor(b.G * 255), math.floor(b.B * 255)
+		return aR == bR and aG == bG and aB == bB
+
+	-- For CFrames, compare to components with epsilon of 0.0001 to avoid floating point inequality
+	elseif typeA == "CFrame" and typeB == "CFrame" then
+		local aComponents, bComponents = {a:GetComponents()}, {b:GetComponents()}
+		for i, aComponent in aComponents do
+			if not fuzzyEq(aComponent, bComponents[i], 0.0001) then
+				return false
+			end
+		end
+		return true
+
+	-- For Vector3s, compare to components with epsilon of 0.0001 to avoid floating point inequality
+	elseif typeA == "Vector3" and typeB == "Vector3" then
+		local aComponents, bComponents = {a.X, a.Y, a.Z}, {b.X, b.Y, b.Z}
+		for i, aComponent in aComponents do
+			if not fuzzyEq(aComponent, bComponents[i], 0.0001) then
+				return false
+			end
+		end
+		return true
+
+	-- For Vector2s, compare to components with epsilon of 0.0001 to avoid floating point inequality
+	elseif typeA == "Vector2" and typeB == "Vector2" then
+		local aComponents, bComponents = {a.X, a.Y}, {b.X, b.Y}
+		for i, aComponent in aComponents do
+			if not fuzzyEq(aComponent, bComponents[i], 0.0001) then
+				return false
+			end
+		end
+		return true
+
+	end
+
+	return false
+end
+
 local function shouldDeleteUnknownInstances(virtualInstance)
 	if virtualInstance.Metadata ~= nil then
 		return not virtualInstance.Metadata.ignoreUnknownInstances
@@ -73,7 +153,8 @@ local function diff(instanceMap, virtualInstances, rootId)
 				local ok, decodedValue = decodeValue(virtualValue, instanceMap)
 
 				if ok then
-					if existingValue ~= decodedValue then
+					if not trueEquals(existingValue, decodedValue) then
+						Log.debug("{}.{} changed from '{}' to '{}'", instance:GetFullName(), propertyName, existingValue, decodedValue)
 						changedProperties[propertyName] = virtualValue
 					end
 				else

plugin/src/ServeSession.lua

@@ -5,8 +5,10 @@ local Packages = script.Parent.Parent.Packages
 local Log = require(Packages.Log)
 local Fmt = require(Packages.Fmt)
 local t = require(Packages.t)
+local Promise = require(Packages.Promise)
 
 local ChangeBatcher = require(script.Parent.ChangeBatcher)
+local encodePatchUpdate = require(script.Parent.ChangeBatcher.encodePatchUpdate)
 local InstanceMap = require(script.Parent.InstanceMap)
 local PatchSet = require(script.Parent.PatchSet)
 local Reconciler = require(script.Parent.Reconciler)
@@ -123,6 +125,10 @@ function ServeSession:onStatusChanged(callback)
 	self.__statusChangedCallback = callback
 end
 
+function ServeSession:setConfirmCallback(callback)
+	self.__userConfirmCallback = callback
+end
+
 function ServeSession:onPatchApplied(callback)
 	self.__patchAppliedCallback = callback
 end
@@ -132,13 +138,12 @@ function ServeSession:start()
 
 	self.__apiContext:connect()
 		:andThen(function(serverInfo)
-			self:__setStatus(Status.Connected, serverInfo.projectName)
 			self:__applyGameAndPlaceId(serverInfo)
 
-			local rootInstanceId = serverInfo.rootInstanceId
-
-			return self:__initialSync(rootInstanceId)
+			return self:__initialSync(serverInfo)
 				:andThen(function()
+					self:__setStatus(Status.Connected, serverInfo.projectName)
+
 					return self:__mainSyncLoop()
 				end)
 		end)
@@ -202,8 +207,8 @@ function ServeSession:__onActiveScriptChanged(activeScript)
 	self.__apiContext:open(scriptId)
 end
 
-function ServeSession:__initialSync(rootInstanceId)
-	return self.__apiContext:read({ rootInstanceId })
+function ServeSession:__initialSync(serverInfo)
+	return self.__apiContext:read({ serverInfo.rootInstanceId })
 		:andThen(function(readResponseBody)
 			-- Tell the API Context that we're up-to-date with the version of
 			-- the tree defined in this response.
@@ -212,14 +217,14 @@ function ServeSession:__initialSync(rootInstanceId)
 			-- For any instances that line up with the Rojo server's view, start
 			-- tracking them in the reconciler.
 			Log.trace("Matching existing Roblox instances to Rojo IDs")
-			self.__reconciler:hydrate(readResponseBody.instances, rootInstanceId, game)
+			self.__reconciler:hydrate(readResponseBody.instances, serverInfo.rootInstanceId, game)
 
 			-- Calculate the initial patch to apply to the DataModel to catch us
 			-- up to what Rojo thinks the place should look like.
 			Log.trace("Computing changes that plugin needs to make to catch up to server...")
 			local success, catchUpPatch = self.__reconciler:diff(
 				readResponseBody.instances,
-				rootInstanceId,
+				serverInfo.rootInstanceId,
 				game
 			)
 
@@ -229,19 +234,50 @@ function ServeSession:__initialSync(rootInstanceId)
 
 			Log.trace("Computed hydration patch: {:#?}", debugPatch(catchUpPatch))
 
-			-- TODO: Prompt user to notify them of this patch, since it's
-			-- effectively a conflict between the Rojo server and the client. In
-			-- the future, we'll ask which changes the user wants to keep.
-
-			local unappliedPatch = self.__reconciler:applyPatch(catchUpPatch)
-
-			if not PatchSet.isEmpty(unappliedPatch) then
-				Log.warn("Could not apply all changes requested by the Rojo server:\n{}",
-					PatchSet.humanSummary(self.__instanceMap, unappliedPatch))
+			local userDecision = "Accept"
+			if self.__userConfirmCallback ~= nil then
+				userDecision = self.__userConfirmCallback(self.__instanceMap, catchUpPatch, serverInfo)
 			end
 
-			if self.__patchAppliedCallback then
-				pcall(self.__patchAppliedCallback, catchUpPatch, unappliedPatch)
+			if userDecision == "Abort" then
+				return Promise.reject("Aborted Rojo sync operation")
+
+			elseif userDecision == "Reject" and self.__twoWaySync then
+				-- The user wants their studio DOM to write back to their Rojo DOM
+				-- so we will reverse the patch and send it back
+
+				local inversePatch = PatchSet.newEmpty()
+
+				-- Send back the current properties
+				for _, change in catchUpPatch.updated do
+					local instance = self.__instanceMap.fromIds[change.id]
+					if not instance then continue end
+
+					local update = encodePatchUpdate(instance, change.id, change.changedProperties)
+					table.insert(inversePatch.updated, update)
+				end
+				-- Add the removed instances back to Rojo
+				-- selene:allow(empty_if, unused_variable)
+				for _, instance in catchUpPatch.removed do
+					-- TODO: Generate ID for our instance and add it to inversePatch.added
+				end
+				-- Remove the additions we've rejected
+				for id, _change in catchUpPatch.added do
+					table.insert(inversePatch.removed, id)
+				end
+
+				self.__apiContext:write(inversePatch)
+
+			elseif userDecision == "Accept" then
+				local unappliedPatch = self.__reconciler:applyPatch(catchUpPatch)
+
+				if not PatchSet.isEmpty(unappliedPatch) then
+					Log.warn("Could not apply all changes requested by the Rojo server:\n{}",
+						PatchSet.humanSummary(self.__instanceMap, unappliedPatch))
+				end
+				if self.__patchAppliedCallback then
+					pcall(self.__patchAppliedCallback, catchUpPatch, unappliedPatch)
+				end
 			end
 		end)
 end