Merge pull request #2838 from tomlau10/fix/func_type_union_overload

Fix incorrect function params' type infer when there is only `@overload`

2 files changed, 40 insertions, 1 deletions

diff --git a/script/vm/compiler.lua b/script/vm/compiler.lua
index 041d287e..50f260c2 100644
--- a/script/vm/compiler.lua
+++ b/script/vm/compiler.lua
@@ -1099,6 +1099,7 @@ local function compileFunctionParam(func, source)
 
     -- local call ---@type fun(f: fun(x: number));call(function (x) end) --> x -> number
     local funcNode = vm.compileNode(func)
+    local found = false
     for n in funcNode:eachObject() do
         if n.type == 'doc.type.function' and n.args[aindex] then
             local argNode = vm.compileNode(n.args[aindex])
@@ -1107,9 +1108,16 @@ local function compileFunctionParam(func, source)
                     vm.setNode(source, an)
                 end
             end
-            return true
+            -- NOTE: keep existing behavior for local call which only set type based on the 1st match
+            if func.parent.type == 'callargs' then
+                return true
+            end
+            found = true
         end
     end
+    if found then
+        return true
+    end
 
     local derviationParam = config.get(guide.getUri(func), 'Lua.type.inferParamType')
     if derviationParam and func.parent.type == 'local' and func.parent.ref then
diff --git a/script/vm/function.lua b/script/vm/function.lua
index 7a15ac5a..21a432c1 100644
--- a/script/vm/function.lua
+++ b/script/vm/function.lua
@@ -359,6 +359,7 @@ end
 ---@return number
 local function calcFunctionMatchScore(uri, args, func)
     if vm.isVarargFunctionWithOverloads(func)
+    or vm.isFunctionWithOnlyOverloads(func)
     or not isAllParamMatched(uri, args, func.args)
     then
         return -1
@@ -490,6 +491,36 @@ function vm.isVarargFunctionWithOverloads(func)
     return false
 end
 
+---@param func table
+---@return boolean
+function vm.isFunctionWithOnlyOverloads(func)
+    if func.type ~= 'function' then
+        return false
+    end
+    if func._onlyOverloadFunction ~= nil then
+        return func._onlyOverloadFunction
+    end
+
+    if not func.bindDocs then
+        func._onlyOverloadFunction = false
+        return false
+    end
+    local hasOverload = false
+    for _, doc in ipairs(func.bindDocs) do
+        if doc.type == 'doc.overload' then
+            hasOverload = true
+        elseif doc.type == 'doc.param'
+        or doc.type == 'doc.return'
+        then
+            -- has specified @param or @return, thus not only @overload
+            func._onlyOverloadFunction = false
+            return false
+        end
+    end
+    func._onlyOverloadFunction = hasOverload
+    return true
+end
+
 ---@param func parser.object
 ---@return boolean
 function vm.isEmptyFunction(func)