From ade3e8a4369b8caf7ddfb01b46c96e5df31a4504 Mon Sep 17 00:00:00 2001
From: Alex Ostrovski <ostrovski.alex@gmail.com>
Date: Sun, 24 Sep 2023 18:51:15 +0300
Subject: [PATCH] Test alphabet-related panics

---
 src/decoder.rs |  2 +-
 src/tests.rs   | 18 ++++++++++++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/src/decoder.rs b/src/decoder.rs
index 21a3cf2..36242cb 100644
--- a/src/decoder.rs
+++ b/src/decoder.rs
@@ -63,7 +63,7 @@ impl Encoding {
             let byte = alphabet_bytes[index];
             compile_assert!(
                 byte < 0x80,
-                "Alphabet '", alphabet => clip(64, ""), "' contains non-ASCII character at ",
+                "Alphabet '", alphabet => clip(64, ""), "' contains non-ASCII character at position ",
                 index => fmt::<usize>()
             );
             let byte_idx = byte as usize;
diff --git a/src/tests.rs b/src/tests.rs
index e0f075e..9be2205 100644
--- a/src/tests.rs
+++ b/src/tests.rs
@@ -102,6 +102,24 @@ fn mixed_base64_alphabet_leads_to_panic() {
     Decoder::Base64.decode::<6>(b"Pj4-Pz8/");
 }
 
+#[test]
+#[should_panic(expected = "Invalid alphabet length 5; must be one of 2, 4, 8, 16, 32, or 64")]
+fn invalid_alphabet_length() {
+    Decoder::custom("what?");
+}
+
+#[test]
+#[should_panic(expected = "Alphabet 'teß' contains non-ASCII character at position 2")]
+fn non_ascii_char_in_alphabet() {
+    Decoder::custom("teß");
+}
+
+#[test]
+#[should_panic(expected = "Alphabet character 'a' is mentioned several times")]
+fn duplicate_char_in_alphabet() {
+    Decoder::custom("alphabet");
+}
+
 #[test]
 #[should_panic(expected = "input decodes to 6 bytes, while type inference implies 3.")]
 fn input_length_overflow() {