From 2518aa4ffe41550bec0a050fd7c71c0512bec9d4 Mon Sep 17 00:00:00 2001
From: kedhammar <alfred.kedhammar@scilifelab.se>
Date: Wed, 12 Jun 2024 12:03:30 +0000
Subject: [PATCH] add assertion

---
 anglerfish/demux/demux.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/anglerfish/demux/demux.py b/anglerfish/demux/demux.py
index 6377baa..4f3ddda 100644
--- a/anglerfish/demux/demux.py
+++ b/anglerfish/demux/demux.py
@@ -292,6 +292,7 @@ def write_demuxedfastq(
 
     gz_buf = 131072
     fq_files = cast(list[str], glob.glob(fastq_in))
+    assert len(fq_files) > 0, f"No fastq files found looking for {fastq_in}."
     for fq in fq_files:
         with subprocess.Popen(
             ["gzip", "-c", "-d", fq], stdout=subprocess.PIPE, bufsize=gz_buf