Add CAT_FASTQ tests for a single pair of files

The test is written to expect that the input files will be renamed, but the
contents will remain the same, i.e. the test uses the md5 hash of the input
files.

tests/modules/cat/fastq/main.nf

@@ -56,3 +56,15 @@ workflow test_cat_fastq_single_end_single_file {
 
     CAT_FASTQ( input )
 }
+
+workflow test_cat_fastq_paired_end_single_file {
+    input = [
+        [ id:'test', single_end: false ],
+        [
+            file(params.test_data['sarscov2']['illumina']['test_1_fastq_gz'], checkIfExists: true),
+            file(params.test_data['sarscov2']['illumina']['test_2_fastq_gz'], checkIfExists: true)
+        ]
+    ]
+
+    CAT_FASTQ( input )
+}

tests/modules/cat/fastq/test.yml

@@ -46,3 +46,14 @@
   files:
     - path: ./output/cat/test.merged.fastq.gz
       md5sum: e325ef7deb4023447a1f074e285761af
+
+- name: cat fastq paired-end-single-file
+  command: nextflow run ./tests/modules/cat/fastq -entry test_cat_fastq_paired_end_single_file -c ./tests/config/nextflow.config -c ./tests/modules/cat/fastq/nextflow.config
+  tags:
+    - cat
+    - cat/fastq
+  files:
+    - path: ./output/cat/test_1.merged.fastq.gz
+      md5sum: e325ef7deb4023447a1f074e285761af
+    - path: ./output/cat/test_2.merged.fastq.gz
+      md5sum: 22342ee8873e5bfa51b4707bb1d56ec6