Add `minetest.get_mapgen_edges` (#12999)

1 files changed, 37 insertions, 0 deletions

diff --git a/games/devtest/mods/unittests/misc.lua b/games/devtest/mods/unittests/misc.lua
index 7c16b7c82..3f327edec 100644
--- a/games/devtest/mods/unittests/misc.lua
+++ b/games/devtest/mods/unittests/misc.lua
@@ -110,3 +110,40 @@ local function test_game_info()
 	assert(info.title == game_conf:get("title"))
 end
 unittests.register("test_game_info", test_game_info)
+
+local function test_mapgen_edges(cb)
+	-- Test that the map can extend to the expected edges and no further.
+	local min_edge, max_edge = minetest.get_mapgen_edges()
+	local min_finished = {}
+	local max_finished = {}
+	local function finish()
+		if #min_finished ~= 1 then
+			return cb("Expected 1 block to emerge around mapgen minimum edge")
+		end
+		if min_finished[1] ~= (min_edge / minetest.MAP_BLOCKSIZE):floor() then
+			return cb("Expected block within minimum edge to emerge")
+		end
+		if #max_finished ~= 1 then
+			return cb("Expected 1 block to emerge around mapgen maximum edge")
+		end
+		if max_finished[1] ~= (max_edge / minetest.MAP_BLOCKSIZE):floor() then
+			return cb("Expected block within maximum edge to emerge")
+		end
+		return cb()
+	end
+	local emerges_left = 2
+	local function emerge_block(blockpos, action, blocks_left, finished)
+		if action ~= minetest.EMERGE_CANCELLED then
+			table.insert(finished, blockpos)
+		end
+		if blocks_left == 0 then
+			emerges_left = emerges_left - 1
+			if emerges_left == 0 then
+				return finish()
+			end
+		end
+	end
+	minetest.emerge_area(min_edge:subtract(1), min_edge, emerge_block, min_finished)
+	minetest.emerge_area(max_edge, max_edge:add(1), emerge_block, max_finished)
+end
+unittests.register("test_mapgen_edges", test_mapgen_edges, {map=true, async=true})