fixes #4299 #12492 #10849; lambda lifting for JS backend (#23484)

fixes #4299 
fixes #12492 
fixes #10849

It binds `function` with `env`: `function.bind(:env)` to ease codegen
for now

1 files changed, 47 insertions, 0 deletions

diff --git a/tests/stdlib/tclosures.nim b/tests/stdlib/tclosures.nim
new file mode 100644
index 000000000..84b033fa8
--- /dev/null
+++ b/tests/stdlib/tclosures.nim
@@ -0,0 +1,47 @@
+discard """
+  targets: "c js"
+"""
+
+import std/assertions
+
+block: # bug #4299
+  proc scopeProc() =
+    proc normalProc() =
+      discard
+
+    proc genericProc[T]() =
+      normalProc()
+
+    genericProc[string]()
+
+  scopeProc()
+
+block: # bug #12492
+  proc foo() =
+    var i = 0
+    proc bar() =
+      inc i
+
+    bar()
+    doAssert i == 1
+
+  foo()
+  static:
+    foo()
+
+block: # bug #10849
+  type
+    Generic[T] = ref object
+      getState: proc(): T
+
+  proc newGeneric[T](): Generic[T] =
+    var state: T
+
+    proc getState[T](): T =
+      state
+
+    Generic[T](getState: getState)
+
+  let g = newGeneric[int]()
+  let state = g.getState()
+  doAssert state == 0