js -r defines nodejs & program result undeclared if unavailable (#21849)

* js -r defines nodejs & program result undefined if unavailable

fixes #16985, fixes #16074

* fix

* add changelog too

* minor word change

lib/pure/unittest.nim

@@ -519,6 +519,12 @@ proc exceptionTypeName(e: ref Exception): string {.inline.} =
   if e == nil: "<foreign exception>"
   else: $e.name
 
+when not declared(setProgramResult):
+  {.warning: "setProgramResult not available on platform, unittest will not" &
+    " give failing exit code on test failure".}
+  template setProgramResult(a: int) =
+    discard
+
 template test*(name, body) {.dirty.} =
   ## Define a single test case identified by `name`.
   ##

lib/std/exitprocs.nim

@@ -69,23 +69,19 @@ proc addExitProc*(cl: proc() {.noconv.}) =
     fun()
     gFuns.add Fun(kind: kNoconv, fun2: cl)
 
-when not defined(nimscript):
+when not defined(nimscript) and (not defined(js) or defined(nodejs)):
   proc getProgramResult*(): int =
     when defined(js) and defined(nodejs):
       asm """
 `result` = process.exitCode;
 """
-    elif not defined(js):
-      result = programResult
     else:
-      doAssert false
+      result = programResult
 
   proc setProgramResult*(a: int) =
     when defined(js) and defined(nodejs):
       asm """
 process.exitCode = `a`;
 """
-    elif not defined(js):
-      programResult = a
     else:
-      doAssert false
+      programResult = a