new diag redundant-return-value

Author: sumneko

changelog.md

@@ -8,6 +8,7 @@
   * `unknown-cast-variable`
   * `cast-type-mismatch`
   * `missing-return-value`
+  * `redundant-return-value`
 * `NEW` settings:
   * `diagnostics.groupSeverity`
   * `diagnostics.groupFileStatus`

locale/zh-cn/script.lua

@@ -132,6 +132,10 @@ DIAG_MISSING_RETURN_VALUE             =
 '至少需要 {min} 个返回值，但此处只返回 {rmax} 个值。'
 DIAG_MISSING_RETURN_VALUE_RANGE       =
 '至少需要 {min} 个返回值，但此处只返回 {rmin} 到 {rmax} 个值。'
+DIAG_REDUNDANT_RETURN_VALUE           =
+'最多只有 {max} 个返回值，但此处返回了第 {rmax} 个值。'
+DIAG_REDUNDANT_RETURN_VALUE_RANGE     =
+'最多只有 {max} 个返回值，但此处返回了第 {rmin} 到第 {rmax} 个值。'
 
 MWS_NOT_SUPPORT         =
 '{} 目前还不支持多工作目录，我可能需要重启才能支持新的工作目录...'

script/core/diagnostics/redundant-return-value.lua

@@ -0,0 +1,69 @@
+local files  = require 'files'
+local guide  = require 'parser.guide'
+local vm     = require 'vm'
+local lang   = require 'language'
+
+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
+    end
+    return false
+end
+
+return function (uri, callback)
+    local state = files.getState(uri)
+    if not state then
+        return
+    end
+
+    guide.eachSourceType(state.ast, 'function', function (source)
+        if not hasDocReturn(source) then
+            return
+        end
+        local _, max = vm.countReturnsOfFunction(source)
+        local returns = source.returns
+        if not returns then
+            return
+        end
+        for _, ret in ipairs(returns) do
+            local rmin, rmax = vm.countList(ret)
+            if rmin > max then
+                for i = max + 1, #ret - 1 do
+                    callback {
+                        start   = ret[i].start,
+                        finish  = ret[i].finish,
+                        message = lang.script('DIAG_REDUNDANT_RETURN_VALUE', {
+                            max  = max,
+                            rmax = i,
+                        }),
+                    }
+                end
+                if #ret == rmax then
+                    callback {
+                        start   = ret[#ret].start,
+                        finish  = ret[#ret].finish,
+                        message = lang.script('DIAG_REDUNDANT_RETURN_VALUE', {
+                            max  = max,
+                            rmax = rmax,
+                        }),
+                    }
+                else
+                    callback {
+                        start   = ret[#ret].start,
+                        finish  = ret[#ret].finish,
+                        message = lang.script('DIAG_REDUNDANT_RETURN_VALUE_RANGE', {
+                            max  = max,
+                            rmin = #ret,
+                            rmax = rmax,
+                        }),
+                    }
+                end
+            end
+        end
+    end)
+end

script/files.lua

@@ -457,7 +457,6 @@ function m.eachFile(suri)
 end
 
 --- Pairs dll files
----@return function
 function m.eachDll()
     local map = {}
     for uri, file in pairs(m.dllMap) do

script/proto/diagnostic.lua

@@ -59,6 +59,7 @@ m.register {
     'redundant-parameter',
     'missing-parameter',
     'missing-return-value',
+    'redundant-return-value',
 } {
     group    = 'unbalanced',
     severity = 'Warning',

script/vm/runner.lua

@@ -113,7 +113,8 @@ end
 ---@param action   parser.object
 ---@param topNode  vm.node
 ---@param outNode? vm.node
----@return vm.node
+---@return vm.node topNode
+---@return vm.node outNode
 function mt:_lookInto(action, topNode, outNode)
     if not action then
         return topNode, outNode

script/workspace/workspace.lua

@@ -397,6 +397,7 @@ end
 
 ---@param uriOrPath uri|string
 ---@return string
+---@return boolean suc
 function m.getRelativePath(uriOrPath)
     local path, uri
     if uriOrPath:sub(1, 5) == 'file:' then

test/diagnostics/common.lua

@@ -885,6 +885,7 @@ TEST [[
 ---@param v T
 ---@param message any
 ---@return T
+---@return any message
 function assert(v, message)
     return v, message
 end
@@ -1734,14 +1735,31 @@ function F()
 end
 ]]
 
-do return end
 TEST [[
 ---@return number, number?
 function F()
     return 1, 1, <!1!>
 end
 ]]
 
+TEST [[
+---@return number, number?
+function F()
+    return 1, 1, <!1!>, <!2!>, <!3!>
+end
+]]
+
+TEST [[
+---@return number, number
+local function r2() end
+
+---@return number, number?
+function F()
+    return 1, <!r2()!>
+end
+]]
+
+do return end
 TEST [[
 ---@return number
 function F()