From 89ab51f3556ac5981a699181131155c560363757 Mon Sep 17 00:00:00 2001
From: Tessa Pierce Ward <bluegenes@users.noreply.github.com>
Date: Thu, 7 Mar 2024 12:52:15 -0800
Subject: [PATCH] index should error out if no sigs to index (#267)

---
 src/index.rs                   |  7 +++++++
 src/python/tests/test_index.py | 25 +++++++++++++++++++++++--
 2 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/src/index.rs b/src/index.rs
index 3747e6f5..3b2aa4a5 100644
--- a/src/index.rs
+++ b/src/index.rs
@@ -20,6 +20,13 @@ pub fn index<P: AsRef<Path>>(
         allow_failed_sigpaths,
     )?;
 
+    if collection.len() == 0 {
+        bail!(
+            "No sketches matching parameters, check input: '{}'",
+            &siglist
+        )
+    }
+
     RevIndex::create(
         output.as_ref(),
         collection.select(selection)?.try_into()?,
diff --git a/src/python/tests/test_index.py b/src/python/tests/test_index.py
index 7fc7b131..f490d2aa 100644
--- a/src/python/tests/test_index.py
+++ b/src/python/tests/test_index.py
@@ -161,11 +161,31 @@ def test_index_empty_siglist(runtmp, capfd):
     assert "Error: Signatures failed to load. Exiting." in captured.err
 
 
-def test_index_nomatch_sig_in_siglist(runtmp, capfd):
+def test_index_nomatch(runtmp, capfd):
     # test index with a siglist file that has (only) a non-matching ksize sig
     siglist = runtmp.output('against.txt')
     db = runtmp.output('db.rdb')
 
+    sig1 = get_test_data('1.fa.k21.sig.gz')
+    make_file_list(siglist, [sig1])
+
+    with pytest.raises(utils.SourmashCommandFailed):
+        runtmp.sourmash('scripts', 'index', siglist,
+                        '-o', db)
+
+    captured = capfd.readouterr()
+    print(runtmp.last_result.out)
+    print(runtmp.last_result.err)
+    print(captured.out)
+    print(captured.err)
+    assert not os.path.exists(db)
+
+
+def test_index_nomatch_sig_in_siglist(runtmp, capfd):
+    # test index with a siglist file that has both matching and non-matching sigs
+    siglist = runtmp.output('against.txt')
+    db = runtmp.output('db.rdb')
+
     sig2 = get_test_data('2.fa.sig.gz')
     sig1 = get_test_data('1.fa.k21.sig.gz')
     make_file_list(siglist, [sig2, sig1])
@@ -174,10 +194,11 @@ def test_index_nomatch_sig_in_siglist(runtmp, capfd):
                         '-o', db)
 
     captured = capfd.readouterr()
-    assert os.path.exists(db) # currently empty file
     print(runtmp.last_result.out)
     print(runtmp.last_result.err)
+    print(captured.out)
     print(captured.err)
+    assert os.path.exists(db)
 
 
 def test_index_zipfile(runtmp, capfd):