fix #1409

4 files changed, 62 insertions, 75 deletions

diff --git a/changelog.md b/changelog.md
index 18d8569a..a3464247 100644
--- a/changelog.md
+++ b/changelog.md
@@ -1,5 +1,8 @@
 # changelog
 
+## 3.5.3
+* `FIX` [#1409](https://github.com/sumneko/lua-language-server/issues/1409)
+
 ## 3.5.2
 `2022-8-1`
 * `FIX` [#1395](https://github.com/sumneko/lua-language-server/issues/1395)
diff --git a/script/core/hover/return.lua b/script/core/hover/return.lua
index b496990b..b71b9e5d 100644
--- a/script/core/hover/return.lua
+++ b/script/core/hover/return.lua
@@ -2,36 +2,6 @@ local vm       = require 'vm.vm'
 local guide    = require 'parser.guide'
 
 ---@param source parser.object
----@return integer
-local function countReturns(source)
-    local n = 0
-
-    local docs = source.bindDocs
-    if docs then
-        for _, doc in ipairs(docs) do
-            if doc.type == 'doc.return' then
-                for _, rtn in ipairs(doc.returns) do
-                    if rtn.returnIndex and rtn.returnIndex > n then
-                        n = rtn.returnIndex
-                    end
-                end
-            end
-        end
-    end
-
-    local returns = source.returns
-    if returns then
-        for _, rtn in ipairs(returns) do
-            if #rtn > n then
-                n = #rtn
-            end
-        end
-    end
-
-    return n
-end
-
----@param source parser.object
 ---@return parser.object[]
 local function getReturnDocs(source)
     local returns = {}
@@ -51,7 +21,7 @@ local function getReturnDocs(source)
 end
 
 local function asFunction(source)
-    local num = countReturns(source)
+    local _, _, num = vm.countReturnsOfFunction(source)
     if num == 0 then
         return nil
     end
diff --git a/script/vm/function.lua b/script/vm/function.lua
index f64b2262..7cde6298 100644
--- a/script/vm/function.lua
+++ b/script/vm/function.lua
@@ -19,12 +19,15 @@ end
 ---@param func parser.object
 ---@return integer min
 ---@return number  max
+---@return integer def
 function vm.countParamsOfFunction(func)
     local min = 0
     local max = 0
+    local def = 0
     if func.type == 'function' then
         if func.args then
             max = #func.args
+            def = max
             for i = #func.args, 1, -1 do
                 local arg = func.args[i]
                 if arg.type == '...' then
@@ -44,6 +47,7 @@ function vm.countParamsOfFunction(func)
     if func.type == 'doc.type.function' then
         if func.args then
             max = #func.args
+            def = max
             for i = #func.args, 1, -1 do
                 local arg = func.args[i]
                 if arg.name and arg.name[1] =='...' then
@@ -55,28 +59,32 @@ function vm.countParamsOfFunction(func)
             end
         end
     end
-    return min, max
+    return min, max, def
 end
 
 ---@param node vm.node
 ---@return integer min
 ---@return number  max
+---@return integer def
 function vm.countParamsOfNode(node)
-    local min, max
+    local min, max, def
     for n in node:eachObject() do
         if n.type == 'function'
         or n.type == 'doc.type.function' then
             ---@cast n parser.object
-            local fmin, fmax = vm.countParamsOfFunction(n)
+            local fmin, fmax, fdef = vm.countParamsOfFunction(n)
             if not min or fmin < min then
                 min = fmin
             end
             if not max or fmax > max then
                 max = fmax
             end
+            if not def or fdef > def then
+                def = fdef
+            end
         end
     end
-    return min or 0, max or math.huge
+    return min or 0, max or math.huge, def or 0
 end
 
 ---@param func parser.object
@@ -84,20 +92,17 @@ end
 ---@param mark? table
 ---@return integer min
 ---@return number  max
+---@return integer def
 function vm.countReturnsOfFunction(func, onlyDoc, mark)
     if func.type == 'function' then
-        ---@type integer?
-        local min
-        ---@type number?
-        local max
+        ---@type integer?, number?, integer?
+        local min, max, def
         local hasDocReturn
         if func.bindDocs then
             local lastReturn
             local n = 0
-            ---@type integer?
-            local dmin
-            ---@type number?
-            local dmax
+            ---@type integer?, number?, integer?
+            local dmin, dmax, ddef
             for _, doc in ipairs(func.bindDocs) do
                 if doc.type == 'doc.return' then
                     hasDocReturn = true
@@ -105,6 +110,7 @@ function vm.countReturnsOfFunction(func, onlyDoc, mark)
                         n = n + 1
                         lastReturn = ret
                         dmax = n
+                        ddef = n
                         if  (not ret.name or ret.name[1] ~= '...')
                         and not vm.compileNode(ret):isNullable() then
                             dmin = n
@@ -123,19 +129,25 @@ function vm.countReturnsOfFunction(func, onlyDoc, mark)
             if dmax and (not max or (dmax > max)) then
                 max = dmax
             end
+            if ddef and (not def or (ddef > def)) then
+                def = ddef
+            end
         end
         if not onlyDoc and not hasDocReturn and func.returns then
             for _, ret in ipairs(func.returns) do
-                local rmin, rmax = vm.countList(ret, mark)
+                local rmin, rmax, ddef = vm.countList(ret, mark)
                 if not min or rmin < min then
                     min = rmin
                 end
                 if not max or rmax > max then
                     max = rmax
                 end
+                if not def or ddef > def then
+                    def = ddef
+                end
             end
         end
-        return min or 0, max or math.huge
+        return min or 0, max or math.huge, def or 0
     end
     if func.type == 'doc.type.function' then
         return vm.countList(func.returns)
@@ -147,52 +159,55 @@ end
 ---@param mark? table
 ---@return integer min
 ---@return number  max
+---@return integer def
 function vm.countReturnsOfCall(func, args, mark)
     local funcs = vm.getMatchedFunctions(func, args, mark)
-    ---@type integer?
-    local min
-    ---@type number?
-    local max
+    ---@type integer?, number?, integer?
+    local min, max, def
     for _, f in ipairs(funcs) do
-        local rmin, rmax = vm.countReturnsOfFunction(f, false, mark)
+        local rmin, rmax, rdef = vm.countReturnsOfFunction(f, false, mark)
         if not min or rmin < min then
             min = rmin
         end
         if not max or rmax > max then
             max = rmax
         end
+        if not def or rdef > def then
+            def = rdef
+        end
     end
-    return min or 0, max or math.huge
+    return min or 0, max or math.huge, def or 0
 end
 
 ---@param list parser.object[]?
 ---@param mark? table
 ---@return integer min
 ---@return number  max
+---@return integer def
 function vm.countList(list, mark)
     if not list then
-        return 0, 0
+        return 0, 0, 0
     end
     local lastArg = list[#list]
     if not lastArg then
-        return 0, 0
+        return 0, 0, 0
     end
     if lastArg.type == '...'
     or lastArg.type == 'varargs' then
-        return #list - 1, math.huge
+        return #list - 1, math.huge, #list
     end
     if lastArg.type == 'call' then
         if not mark then
             mark = {}
         end
         if mark[lastArg] then
-            return #list - 1, math.huge
+            return #list - 1, math.huge, #list
         end
         mark[lastArg] = true
-        local rmin, rmax = vm.countReturnsOfCall(lastArg.node, lastArg.args, mark)
-        return #list - 1 + rmin, #list - 1 + rmax
+        local rmin, rmax, rdef = vm.countReturnsOfCall(lastArg.node, lastArg.args, mark)
+        return #list - 1 + rmin, #list - 1 + rmax, #list - 1 + rdef
     end
-    return #list, #list
+    return #list, #list, #list
 end
 
 ---@param func parser.object
diff --git a/test/hover/init.lua b/test/hover/init.lua
index 40474bf5..e720ffc2 100644
--- a/test/hover/init.lua
+++ b/test/hover/init.lua
@@ -5,22 +5,6 @@ local config     = require 'config'
 
 rawset(_G, 'TEST', true)
 
-local accept = {
-    ['local']          = true,
-    ['setlocal']       = true,
-    ['getlocal']       = true,
-    ['setglobal']      = true,
-    ['getglobal']      = true,
-    ['field']          = true,
-    ['method']         = true,
-    ['string']         = true,
-    ['number']         = true,
-    ['integer']        = true,
-    ['doc.type.name']  = true,
-    ['doc.class.name'] = true,
-    ['function']       = true,
-}
-
 ---@diagnostic disable: await-in-sync
 function TEST(script)
     return function (expect)
@@ -312,7 +296,6 @@ end
 ]]
 [[
 function x()
-  -> unknown
 ]]
 
 TEST [[
@@ -2137,3 +2120,19 @@ local <?x?> = 1 << 2
 [[
 local x: integer = 4
 ]]
+
+TEST [[
+local function test1()
+    return 1, 2, 3
+end
+
+local function <?test2?>()
+    return test1()
+end
+]]
+[[
+function test2()
+  -> integer
+  2. integer
+  3. integer
+]]