1 files changed, 24 insertions, 1 deletions
diff --git a/tests/system/io.nim b/tests/system/io.nim
index b0ccfda9f..3d4df806b 100644
--- a/tests/system/io.nim
+++ b/tests/system/io.nim
@@ -1,5 +1,5 @@
 import
-  unittest, osproc, streams, os
+  unittest, osproc, streams, os, strformat
 const STRING_DATA = "Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet. Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet."
 const TEST_FILE = "tests/testdata/string.txt"
 
@@ -23,3 +23,26 @@ suite "io":
     test "file":
       check:
         readFile(TEST_FILE) == STRING_DATA
+
+
+proc verifyFileSize(sz: int64) =
+  # issue 7121, large file size (2-4GB and >4Gb)
+  const fn = "tmpfile112358"
+  let size_in_mb = sz div 1_000_000
+
+  when defined(windows):
+    discard execProcess(&"fsutil file createnew {fn} {sz}" )
+  else:
+    discard execProcess(&"dd if=/dev/zero of={fn} bs=1000000 count={size_in_mb}")
+
+  doAssert os.getFileSize(fn) == sz # Verify OS filesize by string
+  
+  var f = open(fn)
+  doAssert f.getFileSize() == sz # Verify file handle filesize
+  f.close()
+
+  os.removeFile(fn)
+
+#disable tests for automatic testers
+#for s in [50_000_000'i64, 3_000_000_000, 5_000_000_000]:
+#  verifyFileSize(s)