Added check only single TSV is supplied.

Author: jfy133

docs/usage.md

@@ -601,7 +601,8 @@ and samples.
 The use of the TSV `--input` method is recommended to be used when performing
 more complex procedures such as lane or library merging. You do not need to
 specify `--single_end`, `--bam`, `--colour_chemistry`, `-udg_type` etc. when
-using TSV input - this is defined within the TSV file itself.
+using TSV input - this is defined within the TSV file itself. You can only
+supply a single TSV per run (i.e. `--input '*.tsv'` will not work).
 
 This TSV should look like the following:
 

main.nf

@@ -588,6 +588,8 @@ ch_input_sample = Channel.empty()
 if (tsv_path) {
 
     tsv_file = file(tsv_path)
+    
+    if (tsv_file instanceof List) exit 1, "[nf-core/eager] error: can only accept one TSV file per run."
     if (!tsv_file.exists()) exit 1, "[nf-core/eager] error: input TSV file could not be found. Does the file exist or in the right place? You gave the path: ${params.input}"
 
     ch_input_sample = extract_data(tsv_path)