new diag ``redundant-return-value``

5 files changed, 73 insertions, 2 deletions

diff --git a/script/core/diagnostics/redundant-return-value.lua b/script/core/diagnostics/redundant-return-value.lua
new file mode 100644
index 00000000..8f8422fe
--- /dev/null
+++ b/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
diff --git a/script/files.lua b/script/files.lua
index 3bef6d33..d9148e27 100644
--- a/script/files.lua
+++ b/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
diff --git a/script/proto/diagnostic.lua b/script/proto/diagnostic.lua
index 5972150c..e449d864 100644
--- a/script/proto/diagnostic.lua
+++ b/script/proto/diagnostic.lua
@@ -59,6 +59,7 @@ m.register {
     'redundant-parameter',
     'missing-parameter',
     'missing-return-value',
+    'redundant-return-value',
 } {
     group    = 'unbalanced',
     severity = 'Warning',
diff --git a/script/vm/runner.lua b/script/vm/runner.lua
index 0dd33595..b8ac13fd 100644
--- a/script/vm/runner.lua
+++ b/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
diff --git a/script/workspace/workspace.lua b/script/workspace/workspace.lua
index 3aebc5e0..d24cbfe9 100644
--- a/script/workspace/workspace.lua
+++ b/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