use promises

.luacheckrc

@@ -14,5 +14,5 @@ read_globals = {
 	"minetest",
 
 	-- mods
-	"mapblock_lib", "mtt"
+	"mapblock_lib", "mtt", "Promise"
 }

autoplace.lua

@@ -44,12 +44,8 @@ function building_lib.autoplace(mapblock_pos, playername, autoplacer_name, enabl
         return false, building_name
     end
 
-    local err
-    success, err = building_lib.build(mapblock_pos, playername, building_name, rotation)
-    if not success then
-        return success, err
-    end
-
+    local p = building_lib.build(mapblock_pos, playername, building_name, rotation)
+    p:next(function()
         local autoplacer = building_lib.get_autoplacer(autoplacer_name)
         if enable_propagation and autoplacer.propagate then
             -- propagate changes
@@ -62,6 +58,7 @@ function building_lib.autoplace(mapblock_pos, playername, autoplacer_name, enabl
                 end
             end
         end
+    end)
 
-    return true
+    return p
 end

build.lua

@@ -39,13 +39,12 @@ function building_lib.can_build(mapblock_pos, _, building_name, rotation)
 	return true
 end
 
-function building_lib.build(mapblock_pos, playername, building_name, rotation, callback)
-	callback = callback or function() end
+function building_lib.build(mapblock_pos, playername, building_name, rotation)
 	rotation = rotation or 0
 
 	local success, message = building_lib.can_build(mapblock_pos, playername, building_name, rotation)
 	if not success then
-		return false, message
+		return Promise.rejected(message)
 	end
 
 	local building_def = building_lib.get_building(building_name)
@@ -84,8 +83,11 @@ function building_lib.build(mapblock_pos, playername, building_name, rotation, c
 		replacements = building_def.replace(mapblock_pos, building_def)
 	end
 
+	local promise = Promise.new()
+
 	placement.place(placement, mapblock_pos, building_def, replacements, rotation, function()
-		callback()
+		promise:resolve()
+
 		if old_building_info then
 			-- replacement
 			local old_building_def = building_lib.get_building(old_building_info.name)
@@ -111,7 +113,7 @@ function building_lib.build(mapblock_pos, playername, building_name, rotation, c
 			})
 		end
 	end)
-	return true
+	return promise
 end
 
 -- mapgen build shortcut, only for 1x1x1 sized buildings

build.spec.lua

@@ -13,31 +13,29 @@ building_lib.register_building("building_lib:dummy_v2", {
     }
 })
 
+local mapblock_pos = {x=0, y=0, z=0}
+local building_name = "building_lib:dummy"
+local rotation = 0
+local playername = "singleplayer"
+
+
 mtt.register("build", function(callback)
     -- clear store
     building_lib.store:clear()
 
-    local mapblock_pos = {x=0, y=0, z=0}
-    local building_name = "building_lib:dummy"
-    local rotation = 0
-    local playername = "singleplayer"
-
     -- try to build
     local success, err = building_lib.can_build(mapblock_pos, playername, building_name, rotation)
     assert(not err)
     assert(success)
 
     -- build
-    local callback_called = false
-    success, err = building_lib.build(mapblock_pos, playername, building_name, rotation,
-        function() callback_called = true end
-    )
-    assert(not err)
-    assert(success)
-    assert(callback_called)
+    building_lib.build(mapblock_pos, playername, building_name, rotation)
+    :next(callback)
+end)
 
+mtt.register("try build again", function(callback)
     -- try to build again
-    success, err = building_lib.can_build(mapblock_pos, playername, building_name, rotation)
+    local success, err = building_lib.can_build(mapblock_pos, playername, building_name, rotation)
     assert(err)
     assert(not success)
 
@@ -56,16 +54,13 @@ mtt.register("build", function(callback)
     assert(success)
 
     -- build over
-    callback_called = false
-    success, err = building_lib.build(mapblock_pos, playername, "building_lib:dummy_v2", rotation,
-        function() callback_called = true end
-    )
-    assert(not err)
-    assert(success)
-    assert(callback_called)
+    building_lib.build(mapblock_pos, playername, "building_lib:dummy_v2", rotation)
+    :next(callback)
+end)
 
+mtt.register("remove and verify", function(callback)
     -- try to remove
-    success, err = building_lib.can_remove(mapblock_pos)
+    local success, err = building_lib.can_remove(mapblock_pos)
     assert(not err)
     assert(success)
 
@@ -75,7 +70,7 @@ mtt.register("build", function(callback)
     assert(success)
 
     -- check
-    info = building_lib.get_placed_building_info(mapblock_pos)
+    local info = building_lib.get_placed_building_info(mapblock_pos)
     assert(info == nil)
 
     callback()
@@ -85,23 +80,12 @@ mtt.benchmark("build", function(callback, iterations)
     -- clear store
     building_lib.store:clear()
 
-    local mapblock_pos = {x=0, y=0, z=0}
-    local building_name = "building_lib:dummy"
-    local rotation = 0
-    local playername = "singleplayer"
-
     for _=1,iterations do
         -- build
-        local callback_called = false
-        local success, err = building_lib.build(mapblock_pos, playername, building_name, rotation,
-            function() callback_called = true end
-        )
-        assert(not err)
-        assert(success)
-        assert(callback_called)
+        building_lib.build(mapblock_pos, playername, building_name, rotation)
 
         -- remove
-        success, err = building_lib.remove(mapblock_pos)
+        local success, err = building_lib.remove(mapblock_pos)
         assert(not err)
         assert(success)
     end

build_over.spec.lua

@@ -15,41 +15,38 @@ building_lib.register_building("building_lib:dummy_extension", {
     }
 })
 
-mtt.register("build-over", function(callback)
+local mapblock_pos = {x=0, y=0, z=0}
+local playername = "singleplayer"
+
+mtt.register("build-over (success)", function(callback)
     -- clear store
     building_lib.store:clear()
 
-    local mapblock_pos = {x=0, y=0, z=0}
-    local rotation = 0
-    local playername = "singleplayer"
-
     -- build
-    local callback_called = false
-    local success, err = building_lib.build(mapblock_pos, playername, "building_lib:dummy_base", rotation,
-        function() callback_called = true end
-    )
-    assert(not err)
-    assert(success)
-    assert(callback_called)
-
-    -- build over (wrong angle)
-    success, err = building_lib.build(mapblock_pos, playername, "building_lib:dummy_extension", 90)
-    assert(err)
-    assert(not success)
-
-    -- build over (wrong angle 2)
-    success, err = building_lib.build(mapblock_pos, playername, "building_lib:dummy_extension", 270)
-    assert(err)
-    assert(not success)
-
-    -- build over (180° rotated)
-    callback_called = false
-    success, err = building_lib.build(mapblock_pos, playername, "building_lib:dummy_extension", 180,
-        function() callback_called = true end
-    )
-    assert(not err)
-    assert(success)
-    assert(callback_called)
-
-    callback()
+    building_lib.build(mapblock_pos, playername, "building_lib:dummy_base", 0)
+    :next(callback)
+    :catch(callback)
+end)
+
+mtt.register("build-over (wrong angle)", function(callback)
+    -- build
+    building_lib.build(mapblock_pos, playername, "building_lib:dummy_extension", 90)
+    :catch(function()
+        callback()
+    end)
+end)
+
+mtt.register("build-over (wrong angle 2)", function(callback)
+    -- build
+    building_lib.build(mapblock_pos, playername, "building_lib:dummy_extension", 270)
+    :catch(function()
+        callback()
+    end)
+end)
+
+mtt.register("build-over (180°)", function(callback)
+    -- build
+    building_lib.build(mapblock_pos, playername, "building_lib:dummy_extension", 180)
+    :next(callback)
+    :catch(callback)
 end)

build_tool.lua

@@ -107,10 +107,10 @@ minetest.register_tool("building_lib:place", {
 
         local meta = itemstack:get_meta()
         local buildingname = meta:get_string("buildingname")
-        local success, err = building_lib.build(pointed_mapblock_pos, playername, buildingname, rotation)
-        if not success then
+        building_lib.build(pointed_mapblock_pos, playername, buildingname, rotation)
+        :catch(function(err)
             minetest.chat_send_player(playername, err)
-        end
+        end)
     end,
     on_step = function(itemstack, player)
         local playername = player:get_player_name()

mod.conf

@@ -1,4 +1,4 @@
 name = building_lib
 description = Mapblock granular building placement and tools
-depends = mapblock_lib
+depends = mapblock_lib, promise
 optional_depends = mtt

readme.md

@@ -8,7 +8,12 @@
 local success, message = building_lib.can_build(mapblock_pos, playername, building_name, rotation)
 
 -- build it there
-local success, message = building_lib.build(mapblock_pos, playername, building_name, rotation, callback)
+local promise = building_lib.build(mapblock_pos, playername, building_name, rotation, callback)
+promise:next(function()
+	-- success
+end):catch(function(e)
+	-- error
+end)
 
 -- check if it can be removed
 local success, message = building_lib.can_remove(mapblock_pos)

test/Dockerfile

@@ -7,6 +7,7 @@ RUN apk add git &&\
     cd /root/.minetest/worlds/world/worldmods &&\
     git clone https://github.com/BuckarooBanzay/mtt &&\
     git clone https://github.com/BuckarooBanzay/mtzip &&\
+    git clone https://github.com/BuckarooBanzay/promise &&\
     git clone https://github.com/BuckarooBanzay/mapblock_lib
 
 ENTRYPOINT minetestserver --config /minetest.conf