compat: test numeric for control variable shadowing

Author: JJH090501

spec/lang/code_gen/fornum_spec.lua

@@ -0,0 +1,97 @@
+local util = require("spec.util")
+
+describe("fornum", function()
+   it("5.3: doesn't generate control variable that is local to the iteration", util.gen([[
+      local t: {string} = { "a", "b", "c" }
+
+      for i = 1, #t do
+         i = i + 1
+         print(t[i])
+      end
+   ]], [[
+      local t = { "a", "b", "c" }
+
+      for i = 1, #t do
+         i = i + 1
+         print(t[i])
+      end
+   ]], "5.3"))
+
+   it("5.4: generates control variable that is local to the iteration", util.gen([[
+      local t: {string} = { "a", "b", "c" }
+
+      for i = 1, #t do
+         i = i + 1
+         print(t[i])
+      end
+   ]], [[
+      local t = { "a", "b", "c" }
+
+      for i = 1, #t do local i = i
+         i = i + 1
+         print(t[i])
+      end
+   ]], "5.4"))
+
+   it("5.4: does not generate control variable if not assigned to", util.gen([[
+      local t: {string} = { "a", "b", "c" }
+
+      for i = 1, #t do
+         local j = i + 1
+         print(t[j])
+      end
+   ]], [[
+      local t = { "a", "b", "c" }
+
+      for i = 1, #t do
+         local j = i + 1
+         print(t[j])
+      end
+   ]], "5.4"))
+
+   it("5.4: generates control variable for a loop with a step", util.gen([[
+      for i = 10, 1, -2 do
+         i = i // 2
+         print(i)
+      end
+   ]], [[
+      for i = 10, 1, -2 do local i = i
+         i = i // 2
+         print(i)
+      end
+   ]], "5.4"))
+
+   it("5.4: detects an assignment made from a nested function", util.gen([[
+      for i = 1, 3 do
+         local function bump()
+            i = i + 1
+         end
+         bump()
+         print(i)
+      end
+   ]], [[
+      for i = 1, 3 do local i = i
+         local function bump()
+            i = i + 1
+         end
+         bump()
+         print(i)
+      end
+   ]], "5.4"))
+
+   it("5.4: only shadows the loops that are assigned to", util.gen([[
+      for i = 1, 3 do
+         for j = 1, 3 do
+            j = j + 1
+            print(i, j)
+         end
+      end
+   ]], [[
+      for i = 1, 3 do
+         for j = 1, 3 do local j = j
+            j = j + 1
+            print(i, j)
+         end
+      end
+   ]], "5.4"))
+end)