unbalanced-assignments

1 files changed, 43 insertions, 0 deletions

diff --git a/script/core/diagnostics/unbalanced-assignments.lua b/script/core/diagnostics/unbalanced-assignments.lua
new file mode 100644
index 00000000..35aebb45
--- /dev/null
+++ b/script/core/diagnostics/unbalanced-assignments.lua
@@ -0,0 +1,43 @@
+local files  = require 'files'
+local define = require 'proto.define'
+local lang   = require 'language'
+local guide  = require 'parser.guide'
+
+return function (uri, callback, code)
+    local ast = files.getAst(uri)
+    if not ast then
+        return
+    end
+
+    local last
+
+    local function checkSet(source)
+        if source.value then
+            last = source
+        else
+            if not last then
+                return
+            end
+            if  last.start       <= source.start
+            and last.value.start >= source.finish then
+                callback {
+                    start   = source.start,
+                    finish  = source.finish,
+                    message = lang.script('DIAG_UNBALANCED_ASSIGNMENTS')
+                }
+            else
+                last = nil
+            end
+        end
+    end
+
+    guide.eachSource(ast.ast, function (source)
+        if source.type == 'local'
+        or source.type == 'setlocal'
+        or source.type == 'setglobal'
+        or source.type == 'setfield'
+        or source.type == 'setindex' then
+            checkSet(source)
+        end
+    end)
+end