resolve #1221 generic with optional

3 files changed, 51 insertions, 5 deletions

diff --git a/meta/template/basic.lua b/meta/template/basic.lua
index b4913cc2..4509258e 100644
--- a/meta/template/basic.lua
+++ b/meta/template/basic.lua
@@ -6,7 +6,7 @@ arg = {}
 
 ---#DES 'assert'
 ---@generic T
----@param v T
+---@param v? T
 ---@param message? any
 ---@return T
 function assert(v, message) end
diff --git a/script/vm/sign.lua b/script/vm/sign.lua
index 5c17aa3d..0f5962fd 100644
--- a/script/vm/sign.lua
+++ b/script/vm/sign.lua
@@ -122,13 +122,20 @@ function mt:resolve(uri, args, removeGeneric)
 
     -- remove un-generic type
     ---@param argNode vm.node
+    ---@param sign vm.node
     ---@param knownTypes table<string, true>
     ---@return vm.node
-    local function buildArgNode(argNode, knownTypes)
+    local function buildArgNode(argNode, sign, knownTypes)
         local newArgNode = vm.createNode()
+        local needRemoveNil = sign:hasFalsy()
         for n in argNode:eachObject() do
-            if argNode:hasFalsy() then
-                goto CONTINUE
+            if needRemoveNil then
+                if n.type == 'nil' then
+                    goto CONTINUE
+                end
+                if n.type == 'global' and n.cate == 'type' and n.name == 'nil' then
+                    goto CONTINUE
+                end
             end
             local view = vm.viewObject(n, uri)
             if knownTypes[view] then
@@ -137,6 +144,9 @@ function mt:resolve(uri, args, removeGeneric)
             newArgNode:merge(n)
             ::CONTINUE::
         end
+        if not needRemoveNil and argNode:isOptional() then
+            newArgNode:addOptional()
+        end
         return newArgNode
     end
 
@@ -158,7 +168,7 @@ function mt:resolve(uri, args, removeGeneric)
         local argNode = vm.compileNode(arg)
         local knownTypes, genericNames = getSignInfo(sign)
         if not isAllResolved(genericNames) then
-            local newArgNode = buildArgNode(argNode, knownTypes)
+            local newArgNode = buildArgNode(argNode,sign, knownTypes)
             for n in sign:eachObject() do
                 resolve(n, newArgNode)
             end
diff --git a/test/type_inference/init.lua b/test/type_inference/init.lua
index 9bd66761..5fa70f5f 100644
--- a/test/type_inference/init.lua
+++ b/test/type_inference/init.lua
@@ -2799,3 +2799,39 @@ m.x = {} --> 4th
 
 print(m.<?x?>)
 ]]
+
+TEST 'boolean?' [[
+---@generic T
+---@param x T
+---@return T
+local function echo(x) end
+
+---@type boolean?
+local b
+
+local <?x?> = echo(b)
+]]
+
+TEST 'boolean' [[
+---@generic T
+---@param x T?
+---@return T
+local function echo(x) end
+
+---@type boolean?
+local b
+
+local <?x?> = echo(b)
+]]
+
+TEST 'boolean' [[
+---@generic T
+---@param x? T
+---@return T
+local function echo(x) end
+
+---@type boolean?
+local b
+
+local <?x?> = echo(b)
+]]