1 files changed, 46 insertions, 0 deletions
diff --git a/script-beta/src/core/diagnostics/unused-local.lua b/script-beta/src/core/diagnostics/unused-local.lua
new file mode 100644
index 00000000..22b2e16b
--- /dev/null
+++ b/script-beta/src/core/diagnostics/unused-local.lua
@@ -0,0 +1,46 @@
+local files  = require 'files'
+local guide  = require 'parser.guide'
+local define = require 'proto.define'
+local lang   = require 'language'
+
+local function hasGet(loc)
+    if not loc.ref then
+        return false
+    end
+    for _, ref in ipairs(loc.ref) do
+        if ref.type == 'getlocal' then
+            if not ref.next then
+                return true
+            end
+            local nextType = ref.next.type
+            if  nextType ~= 'setmethod'
+            and nextType ~= 'setfield'
+            and nextType ~= 'setindex' then
+                return true
+            end
+        end
+    end
+    return false
+end
+
+return function (uri, callback)
+    local ast = files.getAst(uri)
+    if not ast then
+        return
+    end
+    guide.eachSourceType(ast.ast, 'local', function (source)
+        local name = source[1]
+        if name == '_'
+        or name == '_ENV' then
+            return
+        end
+        if not hasGet(source) then
+            callback {
+                start   = source.start,
+                finish  = source.finish,
+                tags    = { define.DiagnosticTag.Unnecessary },
+                message = lang.script('DIAG_UNUSED_LOCAL', name),
+            }
+        end
+    end)
+end