Add `hasClosure` to `std/typetraits` (#17501)

* fix nim js cmp fails at CT

* Add `hasClosure` to `std/effecttraits`

* type

* Update changelog.md

Co-authored-by: Timothee Cour <timothee.cour2@gmail.com>

* Update lib/std/effecttraits.nim

Co-authored-by: Timothee Cour <timothee.cour2@gmail.com>
Co-authored-by: Andreas Rumpf <rumpf_a@web.de>

1 files changed, 92 insertions, 0 deletions

diff --git a/tests/stdlib/ttypetraits.nim b/tests/stdlib/ttypetraits.nim
new file mode 100644
index 000000000..de8259ab0
--- /dev/null
+++ b/tests/stdlib/ttypetraits.nim
@@ -0,0 +1,92 @@
+discard """
+  targets: "c cpp js"
+"""
+
+import std/typetraits
+
+
+
+macro testClosure(fn: typed, flag: static bool) =
+  if flag:
+    doAssert hasClosure(fn)
+  else:
+    doAssert not hasClosure(fn)
+
+block:
+  proc h1() =
+    echo 1
+
+  testClosure(h1, false)
+
+  proc h2() {.nimcall.} =
+    echo 2
+
+  testClosure(h2, false)
+
+
+block:
+  proc fn(): auto =
+    proc hello() {.nimcall.} =
+      echo 3
+    hello
+
+  let name = fn()
+  testClosure(name, false)
+
+block:
+  proc fn(): auto =
+    proc hello() =
+      echo 3
+    hello
+
+  let name = fn()
+  testClosure(name, false)
+
+block:
+  proc fn(): auto =
+    var x = 0
+    proc hello() =
+      echo 3
+      inc x
+    hello
+
+  let name = fn()
+  testClosure(name, true)
+
+block:
+  proc fn(): auto =
+    var x = 0
+    proc hello() {.closure.} =
+      echo 3
+      inc x
+    hello
+
+  let name = fn()
+  testClosure(name, true)
+
+block:
+  proc fn(): auto =
+    var x = 0
+    proc hello() {.closure.} =
+      echo 3
+      inc x
+    hello
+
+  let name = fn()
+  testClosure(name, true)
+
+  let name2 = name
+  testClosure(name2, true)
+
+block:
+  iterator hello(): int =
+    yield 1
+
+  testClosure(hello, false)
+
+when not defined(js):
+  block:
+    iterator hello(): int {.closure.}=
+      yield 1
+
+    testClosure(hello, true)