As it turns out, not fully testing new features is not necessarily a
good idea ...
This patch follows up 1F616EMO's patch by
* Making get_wagon_prototype return the resolved alias,
* Handling recursive wagon alises (in particular, loops), and
* Adding (partial) unittest for the wagon aliasing system. [v2]: The
testcases are complemented a bit more to cover situations where the
alias resolution system should return nil.
[v2]: This patch should hopefully also warn about not spawning wagons.
Note that this only warns about the missing wagon entity and does _not_
actually fix the issue.
How to test:
* In a world with both advtrains_train_subway and advtrains_train_japan
enabled, place a subway wagon, a Japanese engine, and a regular
Japanese wagon.
* Add the test mod to the world; do NOT remove advtrains_train_japan.
* Restart the world. Notice that the Japanese wagons still appear as
Japanese wagons despite being aliased to subway wagons.
* Restart the world without the advtrains_train_japan mod. Notice that
the engine appears as the subway wagon while the regular Japanese
wagon appears as the wagon placeholder. [v2]: Also note that the
warning message about the missing wagon prototype still mentions the
regular Japanese wagon.
* Restart the world again with the advtrains_train_japan mod. Notice
that both type of Japanese wagons reappear as Japanese wagons.
* Observe that unittests work.
Test mod:
advtrains.register_wagon_alias("advtrains:engine_japan", "advtrains:subway_wagon")
advtrains.register_wagon_alias("advtrains:wagon_japan", "advtrains:wagon_japan")
---
advtrains/spec/wagons_spec.lua | 40 ++++++++++++++++++++++++++++++++++
advtrains/trainlogic.lua | 13 +++++++++--
advtrains/wagons.lua | 35 +++++++++++++++++++----------
3 files changed, 74 insertions(+), 14 deletions(-)
create mode 100644 advtrains/spec/wagons_spec.lua
diff --git a/advtrains/spec/wagons_spec.lua b/advtrains/spec/wagons_spec.lua
new file mode 100644
index 0000000..df0687b
--- /dev/null
+++ b/advtrains/spec/wagons_spec.lua
@@ -0,0 +1,40 @@
+require "mineunit"
+mineunit "core"
+
+_G.advtrains = {
+ wagon_load_range = 32
+}
+sourcefile "wagons"
+
+local myproto = {_test = true}
+advtrains.register_wagon(":mywagon", myproto, "My wagon", "", false)
+advtrains.register_wagon_alias(":myalias", ":mywagon")
+advtrains.register_wagon_alias(":myotheralias", ":myalias")
+
+local myotherproto = {_other = true}
+advtrains.register_wagon(":noalias", myotherproto, "Not aliased wagon", "", false)
+advtrains.register_wagon_alias(":noalias", ":mywagon")
+
+advtrains.register_wagon_alias(":nilalias", ":nil")
+
+advtrains.register_wagon_alias(":R1", ":R2")
+advtrains.register_wagon_alias(":R2", ":R3")
+advtrains.register_wagon_alias(":R3", ":R1")
+
+describe("wagon alias system", function()
+ it("should work", function()
+ assert.same({":mywagon", myproto}, {advtrains.resolve_wagon_alias(":myalias")})
+ assert.equal(myproto, advtrains.wagon_prototypes[":myalias"])
+ assert.same({":mywagon", myproto}, {advtrains.resolve_wagon_alias(":myotheralias")})
+ end)
+ it("should respect wagon registration", function()
+ assert.same({":noalias", myotherproto}, {advtrains.resolve_wagon_alias(":noalias")})
+ end)
+ it("should handle recursive loops", function()
+ assert.same({}, {advtrains.resolve_wagon_alias(":R1")})
+ end)
+ it("should return nil for missing entries", function()
+ assert.same({}, {advtrains.resolve_wagon_alias(":what")})
+ assert.same({}, {advtrains.resolve_wagon_alias(":nilalias")})
+ end)
+end)
diff --git a/advtrains/trainlogic.lua b/advtrains/trainlogic.lua
index f136577..4db349a 100644
--- a/advtrains/trainlogic.lua
+++ b/advtrains/trainlogic.lua
@@ -1117,8 +1117,17 @@ function advtrains.spawn_wagons(train_id)
if advtrains.position_in_range(pos, ablkrng) then
--atdebug("wagon",w_id,"spawning")
local wt = advtrains.get_wagon_prototype(data)
- local wagon = minetest.add_entity(pos, wt):get_luaentity()
- wagon:set_id(w_id)
+ local wobj = minetest.add_entity(pos, wt)
+ if not wobj then
+ atwarn("Failed to spawn wagon", w_id, "of type", wt)
+ else
+ local wagon = wobj:get_luaentity()
+ if not wagon then
+ atwarn("Wagon", w_id, "of type", wt, "spawned with nil luaentity")
+ else
+ wagon:set_id(w_id)
+ end
+ end
end
end
else
diff --git a/advtrains/wagons.lua b/advtrains/wagons.lua
index 536c8d4..144294e 100644
--- a/advtrains/wagons.lua
+++ b/advtrains/wagons.lua
@@ -16,15 +16,8 @@ advtrains.wagons = {}
advtrains.wagon_alias = {}
advtrains.wagon_prototypes = setmetatable({}, {
__index = function(t, k)
- local rtn_val = rawget(t, k)
- if rtn_val ~= nil then
- return rtn_val
- end
- local alias = advtrains.wagon_alias[k]
- if alias then
- return rawget(t, alias)
- end
- return nil
+ local _, proto = advtrains.resolve_wagon_alias(k)
+ return proto
end
})
advtrains.wagon_objects = {}
@@ -1332,17 +1325,35 @@ function advtrains.get_wagon_prototype(data)
data.type = data.entity_name
data.entity_name = nil
end
- if not wt or not advtrains.wagon_prototypes[wt] then
+ local rt, proto = advtrains.resolve_wagon_alias(wt)
+ if not rt then
atwarn("Unable to load wagon type",wt,", using placeholder")
- wt="advtrains:wagon_placeholder"
+ rt = "advtrains:wagon_placeholder"
+ proto = advtrains.wagon_prototypes[rt]
end
- return wt, advtrains.wagon_prototypes[wt]
+ return rt, proto
end
function advtrains.register_wagon_alias(src, dst)
advtrains.wagon_alias[src] = dst
end
+local function recursive_resolve_alias(name, seen)
+ local prototype = rawget(advtrains.wagon_prototypes, name)
+ if prototype then
+ return name, prototype
+ end
+ local resolved = advtrains.wagon_alias[name]
+ if resolved and not seen[resolved] then
+ seen[name] = true
+ return recursive_resolve_alias(resolved, seen)
+ end
+end
+
+function advtrains.resolve_wagon_alias(name)
+ return recursive_resolve_alias(name, {})
+end
+
function advtrains.standard_inventory_formspec(self, pname, invname)
--[[minetest.chat_send_player(pname, string.format("self=%s, pname=%s, invname=%s", self, pname, invname))
for k,v in pairs(self) do
--
2.46.0