fix prelude regression refs #16238: include prelude doesn't interfere with nim doc (#17111)

* fix bug1 from #16238 nim doc now works with include prelude

* fix for windows

* fixup

doc/prelude.rst

@@ -1,29 +0,0 @@
-Prelude
-=======
-
-This is an include file that simply imports common modules for your convenience:
-
-.. code-block:: nim
-  include std/prelude
-
-Same as:
-
-.. code-block:: nim
-  import std/[os, strutils, times, parseutils, hashes, tables, sets, sequtils, parseopt]
-
-
-Examples
-========
-
-Get the basic most common imports ready to start coding using ``prelude``:
-
-.. code-block:: nim
-  include std/prelude
-
-  echo now()
-  echo getCurrentDir()
-  echo "Hello $1".format("World")
-
-
-See also:
-- `Sugar <sugar.html>`_

lib/pure/prelude.nim

@@ -7,18 +7,22 @@
 #    distribution, for details about the copyright.
 #
 
-## This is an include file that simply imports common modules for your
-## convenience:
-##
-## .. code-block:: nim
-##   include std/prelude
-##
-## Same as:
-##
-## .. code-block:: nim
-##   import std/[os, strutils, times, parseutils, hashes, tables, sets, sequtils, parseopt]
+when defined(nimdoc) and isMainModule:
+  from std/compileSettings import nil
+  when compileSettings.querySetting(compileSettings.SingleValueSetting.projectFull) == currentSourcePath:
+    ## This is an include file that simply imports common modules for your convenience.
+    runnableExamples:
+      include std/prelude
+        # same as:
+        # import std/[os, strutils, times, parseutils, hashes, tables, sets, sequtils, parseopt]
+      let x = 1
+      assert "foo $# $#" % [$x, "bar"] == "foo 1 bar"
+      assert toSeq(1..3) == @[1, 2, 3]
+      when not defined(js) or defined(nodejs):
+        assert getCurrentDir().len > 0
+        assert ($now()).startsWith "20"
 
-# xxx deduplicate with prelude.rst
+  # xxx `nim doc -b:js -d:nodejs --doccmd:-d:nodejs lib/pure/prelude.nim` fails for some reason
+  # specific to `nim doc`, but the code otherwise works with nodejs.
 
 import std/[os, strutils, times, parseutils, hashes, tables, sets, sequtils, parseopt]
-

tools/kochdocs.nim

@@ -143,7 +143,6 @@ lib/posix/termios.nim
 
   # some of these are include files so shouldn't be docgen'd
   ignoredModules = """
-lib/pure/prelude.nim
 lib/pure/future.nim
 lib/pure/collections/hashcommon.nim
 lib/pure/collections/tableimpl.nim