diagnostics consider `overload`

resolve #1582

5 files changed, 69 insertions, 44 deletions

diff --git a/changelog.md b/changelog.md
index 4988b337..6ef6f3c5 100644
--- a/changelog.md
+++ b/changelog.md
@@ -29,6 +29,11 @@ server will generate `doc.json` and `doc.md` in `LOGPATH`.
 
   print(class.a.b.c.e.f.g) --> infered as integer
   ```
+* `CHG` [#1582] the following diagnostics consider `overload`
+  * `missing-return`
+  * `missing-return-value`
+  * `redundant-return-value`
+  * `return-type-mismatch`
 * `FIX` [#1567]
 * `FIX` [#1593]
 * `FIX` [#1595]
@@ -41,6 +46,7 @@ server will generate `doc.json` and `doc.md` in `LOGPATH`.
 [#1558]: https://github.com/sumneko/lua-language-server/issues/1558
 [#1561]: https://github.com/sumneko/lua-language-server/issues/1561
 [#1567]: https://github.com/sumneko/lua-language-server/issues/1567
+[#1582]: https://github.com/sumneko/lua-language-server/issues/1582
 [#1593]: https://github.com/sumneko/lua-language-server/issues/1593
 [#1595]: https://github.com/sumneko/lua-language-server/issues/1595
 [#1606]: https://github.com/sumneko/lua-language-server/issues/1606
diff --git a/script/core/diagnostics/missing-return-value.lua b/script/core/diagnostics/missing-return-value.lua
index 3aa7bd55..9eab7074 100644
--- a/script/core/diagnostics/missing-return-value.lua
+++ b/script/core/diagnostics/missing-return-value.lua
@@ -5,27 +5,9 @@ local lang   = require 'language'
 local await  = require 'await'
 
 ---@param func parser.object
-local function hasDocReturn(func)
-    if not func.bindDocs then
-        return false
-    end
-    for _, doc in ipairs(func.bindDocs) do
-        if doc.type == 'doc.return' then
-            return true
-        end
-        if doc.type == 'doc.overload' then
-            if #doc.overload.returns > 0 then
-                return true
-            end
-        end
-    end
-    return false
-end
-
----@param func parser.object
 ---@return integer
 local function getReturnsMin(func)
-    local min = vm.countReturnsOfFunction(func)
+    local min = vm.countReturnsOfFunction(func, true)
     if min == 0 then
         return 0
     end
@@ -57,9 +39,6 @@ return function (uri, callback)
         if not returns then
             return
         end
-        if not hasDocReturn(source) then
-            return
-        end
         local min = getReturnsMin(source)
         if min == 0 then
             return
diff --git a/script/core/diagnostics/missing-return.lua b/script/core/diagnostics/missing-return.lua
index e3539ac0..d90311d7 100644
--- a/script/core/diagnostics/missing-return.lua
+++ b/script/core/diagnostics/missing-return.lua
@@ -49,6 +49,27 @@ local function isEmptyFunction(func)
     return finishRow - startRow <= 1
 end
 
+---@param func parser.object
+---@return integer
+local function getReturnsMin(func)
+    local min = vm.countReturnsOfFunction(func, true)
+    if min == 0 then
+        return 0
+    end
+    for _, doc in ipairs(func.bindDocs) do
+        if doc.type == 'doc.overload' then
+            local n = vm.countReturnsOfFunction(doc.overload)
+            if n == 0 then
+                return 0
+            end
+            if n < min then
+                min = n
+            end
+        end
+    end
+    return min
+end
+
 ---@async
 return function (uri, callback)
     local state = files.getState(uri)
@@ -63,7 +84,7 @@ return function (uri, callback)
             return
         end
         await.delay()
-        if vm.countReturnsOfFunction(source, true) == 0 then
+        if getReturnsMin(source) == 0 then
             return
         end
         if hasReturn(source) then
diff --git a/script/core/diagnostics/redundant-return-value.lua b/script/core/diagnostics/redundant-return-value.lua
index 36432f98..9b913438 100644
--- a/script/core/diagnostics/redundant-return-value.lua
+++ b/script/core/diagnostics/redundant-return-value.lua
@@ -4,16 +4,25 @@ local vm     = require 'vm'
 local lang   = require 'language'
 local await  = require 'await'
 
-local function hasDocReturn(func)
-    if not func.bindDocs then
-        return false
+---@param func parser.object
+---@return number
+local function getReturnsMax(func)
+    local _, max = vm.countReturnsOfFunction(func, true)
+    if max == math.huge then
+        return max
     end
     for _, doc in ipairs(func.bindDocs) do
-        if doc.type == 'doc.return' then
-            return true
+        if doc.type == 'doc.overload' then
+            local _, n = vm.countReturnsOfFunction(doc.overload)
+            if n == math.huge then
+                return n
+            end
+            if n > max then
+                max = n
+            end
         end
     end
-    return false
+    return max
 end
 
 ---@async
@@ -25,15 +34,12 @@ return function (uri, callback)
 
     ---@async
     guide.eachSourceType(state.ast, 'function', function (source)
-        await.delay()
-        if not hasDocReturn(source) then
-            return
-        end
-        local _, max = vm.countReturnsOfFunction(source)
         local returns = source.returns
         if not returns then
             return
         end
+        await.delay()
+        local max = getReturnsMax(source)
         for _, ret in ipairs(returns) do
             local rmin, rmax = vm.countList(ret)
             if rmin > max then
diff --git a/test/diagnostics/type-check.lua b/test/diagnostics/type-check.lua
index 5450eda4..a938f14c 100644
--- a/test/diagnostics/type-check.lua
+++ b/test/diagnostics/type-check.lua
@@ -810,16 +810,29 @@ local function f(x)
 end
 ]]
 
---TEST [[
------@param x boolean
------@return number
------@overload fun()
---local function f(x)
---    if x then
---        return 1
---    end
---end
---]]
+TEST [[
+---@param x boolean
+---@return number
+---@overload fun()
+local function f(x)
+    if x then
+        return 1
+    end
+end
+]]
+
+TEST [[
+---@param x boolean
+---@return number
+---@overload fun(): boolean, boolean
+local function f(x)
+    if x then
+        return 1
+    else
+        return false, false
+    end
+end
+]]
 
 config.remove(nil, 'Lua.diagnostics.disable', 'unused-local')
 config.remove(nil, 'Lua.diagnostics.disable', 'unused-function')