From 0a6a1094f7387daa92c7bbcbb1c08e2c0c3620aa Mon Sep 17 00:00:00 2001
From: Manuel Holtgrewe <manuel.holtgrewe@bih-charite.de>
Date: Mon, 27 Mar 2023 13:11:12 +0200
Subject: [PATCH] fix: cases of empty sequence (#61)

---
 src/mapper/altseq.rs | 12 ++++++++++--
 src/sequences.rs     | 10 ++++++----
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/src/mapper/altseq.rs b/src/mapper/altseq.rs
index b05607f..250880f 100644
--- a/src/mapper/altseq.rs
+++ b/src/mapper/altseq.rs
@@ -782,7 +782,11 @@ impl AltSeqToHgvsp {
             aa_end = aa_start.clone();
 
             reference = "".to_owned();
-            alternative = insertion.chars().next().unwrap().to_string();
+            alternative = insertion
+                .chars()
+                .next()
+                .map(|c| c.to_string())
+                .unwrap_or_default();
             is_ext = true;
         } else if *is_frameshift {
             // frameshift
@@ -793,7 +797,11 @@ impl AltSeqToHgvsp {
             aa_end = aa_start.clone();
 
             reference = "".to_owned();
-            alternative = insertion.chars().next().unwrap().to_string();
+            alternative = insertion
+                .chars()
+                .next()
+                .map(|c| c.to_string())
+                .unwrap_or_default();
 
             fsext_len = insertion
                 .find('*')
diff --git a/src/sequences.rs b/src/sequences.rs
index 002262e..8aca509 100644
--- a/src/sequences.rs
+++ b/src/sequences.rs
@@ -541,12 +541,14 @@ pub fn aa_to_aa3(seq: &str) -> Result<String, anyhow::Error> {
 #[allow(dead_code)]
 pub fn aa1_to_aa3(seq: &str) -> Result<String, anyhow::Error> {
     let mut result = String::new();
+    if seq.is_empty() {
+        return Ok(result);
+    }
 
     for i in 0..seq.len() {
-        let aa3 = AA1_TO_AA3_LUT.get(&seq[i..(i + 1)]).ok_or(anyhow::anyhow!(
-            "Invalid 1-letter amino acid: {}",
-            &seq[i..(i + 1)]
-        ))?;
+        let aa3 = AA1_TO_AA3_LUT
+            .get(&seq[i..(i + 1)])
+            .ok_or_else(|| anyhow::anyhow!("Invalid 1-letter amino acid: {}", &seq[i..(i + 1)]))?;
         result.push_str(aa3);
     }