adds regression tests (#25906)

closes #22842, closes #21252, closes #19312, 
closes #16956, closes #16416, closes #14913, closes #13296,
closes #12424, closes #10902, closes #9892, closes #9617

tests/arc/t19312.nim

@@ -0,0 +1,19 @@
+discard """
+  matrix: "--mm:orc"
+  output: '''(val: 1)
+(val: 1)'''
+"""
+# Issue #19312: copied ref object is converted to nil if not used in declaration module under ARC/ORC
+# https://github.com/nim-lang/Nim/issues/19312
+
+type
+  Wrapper* = object
+    val: int
+  RefWrapper* = ref Wrapper
+
+let
+  a* = RefWrapper(val: 1)
+  b* = a
+
+echo b[]
+echo a[]

tests/async/t16416.nim

@@ -0,0 +1,17 @@
+discard """
+  output: '''done'''
+"""
+# Issue #16416: Can't call closure iterator from inside an async function
+# https://github.com/nim-lang/Nim/issues/16416
+
+import asyncdispatch
+
+iterator x(): int {.closure.} =
+  yield 1
+
+proc y() {.async.} =
+  for z in x():
+    discard
+
+waitFor y()
+echo "done"

tests/concepts/t14913.nim

@@ -0,0 +1,23 @@
+discard """
+  output: '''done'''
+"""
+# Issue #14913: Compiler crash when using a default parameter value for a parameter whose type is a concept
+# https://github.com/nim-lang/Nim/issues/14913
+
+type
+  State = object
+  MoreState = object
+  StringRecord = concept x, type T
+    for k, v in fieldPairs(x):
+      k is string
+      v is string
+  StateStrings = object
+    a, b: string
+
+proc combine(a: State, b: MoreState): StateStrings = discard
+
+proc whoops[T: StringRecord](a: State, b: MoreState, c: T = a.combine(b)) =
+  discard
+
+whoops(State(), MoreState())
+echo "done"

tests/destructor/t9617.nim

@@ -0,0 +1,20 @@
+discard """
+  output: '''done'''
+"""
+# Issue #9617: Compiler error with sequences of destructible types
+# https://github.com/nim-lang/Nim/issues/9617
+
+type
+  Foo* = object
+
+  Bar = ref object
+    s: seq[Foo]
+
+proc `=destroy`*(self: var Foo) = echo "hi"
+
+proc test(b: Bar) =
+  for i in b.s:
+    discard
+
+test(Bar())
+echo "done"

tests/errmsgs/t16956.nim

@@ -0,0 +1,11 @@
+discard """
+  action: "reject"
+  errormsg: "invalid type: 'iterator (a: int, b: int, step: Positive): int{.inline, noSideEffect, gcsafe.}' for const"
+  line: 9
+"""
+# Issue #16956: Error: not unused depending on unrelated code changes
+# https://github.com/nim-lang/Nim/issues/16956
+
+const f2 = case true
+  of true:  countup[int]
+  of false: countdown[int]

tests/generics/t21252.nim

@@ -0,0 +1,35 @@
+discard """
+  output: '''done'''
+"""
+# Issue #21252: Compiler SIGSEGV when not instantiating generic proc correctly
+# https://github.com/nim-lang/Nim/issues/21252
+
+type
+  Addr = object
+    layerIdx: int
+
+type Msg0 = object
+  address: Addr
+  selSample: tuple[inArrays: seq[seq[float64]], target: seq[float64], gradientStrength: float64]
+
+type WeightUpdate = object
+  address: Addr
+
+proc workerThread[
+  layer0StimulusWidth: static int
+  ]() =
+  discard
+
+proc z*[
+  layer0StimulusWidth: static int,
+  nUnitsPerLayer: static seq[int],
+  targetLen: static int
+  ]() =
+  workerThread[layer0StimulusWidth]()
+
+when isMainModule:
+  const layer0StimulusWidth: int = 5*29
+  const nUnitsPerLayer: seq[int] = @[50, 5]
+  const targetLen: int = 5
+  z[layer0StimulusWidth, nUnitsPerLayer, targetLen]()
+  echo "done"

tests/macros/t10902.nim

@@ -0,0 +1,31 @@
+discard """
+  output: '''done'''
+"""
+# Issue #10902: cannot instantiate T when generating AST from macro
+# https://github.com/nim-lang/Nim/issues/10902
+
+import macros
+
+type
+  Base[T] = ref object
+
+macro genCloneProc(typeWithGenArg: untyped): untyped =
+  result = newProc(
+    ident "clone", [
+      typeWithGenArg,
+      newIdentDefs(
+        ident "self",
+        typeWithGenArg,
+      )
+    ],
+    newStmtList(
+      newNimNode(nnkDiscardStmt).add(newEmptyNode())
+    )
+  )
+  let genericParamIdent = typeWithGenArg[1]
+  result[2] = newNimNode(nnkGenericParams)
+  result[2].add(newIdentDefs(genericParamIdent, newEmptyNode()))
+
+genCloneProc(Base[T])
+
+echo "done"

tests/macros/t13296.nim

@@ -0,0 +1,21 @@
+discard """
+  output: '''done'''
+"""
+# Issue #13296: Error: not unused with a macro
+# https://github.com/nim-lang/Nim/issues/13296
+
+import macros
+macro dType(body: untyped) =
+  if body.kind == nnkCall:
+    var typ = newNimNode(nnkStmtList)
+    typ.add quote do:
+      discard
+  elif body.kind == nnkTypeSection:
+    result = newStmtList(
+      body
+    )
+
+dType:
+  echo "hi"
+
+echo "done"

tests/macros/t9892.nim

@@ -0,0 +1,16 @@
+discard """
+  output: '''1'''
+"""
+# Issue #9892: Incorrect "Error: not unused" from else branch in macro
+# https://github.com/nim-lang/Nim/issues/9892
+
+import macros
+
+macro foo(x: typed): untyped =
+  result = newNimNode(nnkStmtListExpr)
+  if x.kind == nnkStmtListExpr:
+    result.add x
+  else:
+    result = x
+
+echo foo(1)

tests/pragmas/t12424.nim

@@ -0,0 +1,8 @@
+discard """
+  nimout: '''t12424.nim(8, 10) Warning: This is a test warning from user code [User]'''
+"""
+# Issue #12424: Warning and Hint Pragmas do not print to console when declared from a std lib module
+# https://github.com/nim-lang/Nim/issues/12424
+# This test verifies that warning pragmas in user code work correctly.
+
+{.warning: "This is a test warning from user code".}

tests/typerel/t22842.nim

@@ -0,0 +1,11 @@
+discard """
+  output: '''done'''
+"""
+# Issue #22842: internal error: getTypeDescAux(tyAnything) with auto in proc type
+# https://github.com/nim-lang/Nim/issues/22842
+
+proc register(cb: proc (e: auto): void) = discard
+
+register(proc (e: int) = echo e)
+
+echo "done"