--- a/tests/test-persistent-nodemap.t	Fri Feb 14 15:03:26 2020 +0100
+++ b/tests/test-persistent-nodemap.t	Tue Feb 11 11:18:52 2020 +0100
@@ -84,3 +84,37 @@
   $ hg debugnodemap --check
   revision in index:   5002
   revision in nodemap: 5002
+
+Test code path without mmap
+---------------------------
+
+  $ echo bar > bar
+  $ hg add bar
+  $ hg ci -m 'bar' --config experimental.exp-persistent-nodemap.mmap=no
+
+  $ hg debugnodemap --check --config experimental.exp-persistent-nodemap.mmap=yes
+  revision in index:   5003
+  revision in nodemap: 5003
+  $ hg debugnodemap --check --config experimental.exp-persistent-nodemap.mmap=no
+  revision in index:   5003
+  revision in nodemap: 5003
+
+
+#if pure
+  $ hg debugnodemap --metadata
+  uid: ???????????????? (glob)
+  tip-rev: 5002
+  data-length: 123328
+  data-unused: 384
+  $ f --sha256 .hg/store/00changelog-*.nd --size
+  .hg/store/00changelog-????????????????.nd: size=123328, sha256=10d26e9776b6596af0f89143a54eba8cc581e929c38242a02a7b0760698c6c70 (glob)
+
+#else
+  $ hg debugnodemap --metadata
+  uid: ???????????????? (glob)
+  tip-rev: 5002
+  data-length: 122944
+  data-unused: 0
+  $ f --sha256 .hg/store/00changelog-*.nd --size
+  .hg/store/00changelog-????????????????.nd: size=122944, sha256=755976b22b64ab680401b45395953504e64e7fa8c31ac570f58dee21e15f9bc0 (glob)
+#endif