1 files changed, 81 insertions, 0 deletions
diff --git a/third_party/rust/base64/src/tests.rs b/third_party/rust/base64/src/tests.rs
new file mode 100644
index 0000000000..88748de79c
--- /dev/null
+++ b/third_party/rust/base64/src/tests.rs
@@ -0,0 +1,81 @@
+use crate::{decode_config, encode::encoded_size, encode_config_buf, CharacterSet, Config};
+
+use std::str;
+
+use rand::{
+    distributions::{Distribution, Uniform},
+    seq::SliceRandom,
+    FromEntropy, Rng,
+};
+
+#[test]
+fn roundtrip_random_config_short() {
+    // exercise the slower encode/decode routines that operate on shorter buffers more vigorously
+    roundtrip_random_config(Uniform::new(0, 50), 10_000);
+}
+
+#[test]
+fn roundtrip_random_config_long() {
+    roundtrip_random_config(Uniform::new(0, 1000), 10_000);
+}
+
+pub fn assert_encode_sanity(encoded: &str, config: Config, input_len: usize) {
+    let input_rem = input_len % 3;
+    let expected_padding_len = if input_rem > 0 {
+        if config.pad {
+            3 - input_rem
+        } else {
+            0
+        }
+    } else {
+        0
+    };
+
+    let expected_encoded_len = encoded_size(input_len, config).unwrap();
+
+    assert_eq!(expected_encoded_len, encoded.len());
+
+    let padding_len = encoded.chars().filter(|&c| c == '=').count();
+
+    assert_eq!(expected_padding_len, padding_len);
+
+    let _ = str::from_utf8(encoded.as_bytes()).expect("Base64 should be valid utf8");
+}
+
+fn roundtrip_random_config(input_len_range: Uniform<usize>, iterations: u32) {
+    let mut input_buf: Vec<u8> = Vec::new();
+    let mut encoded_buf = String::new();
+    let mut rng = rand::rngs::SmallRng::from_entropy();
+
+    for _ in 0..iterations {
+        input_buf.clear();
+        encoded_buf.clear();
+
+        let input_len = input_len_range.sample(&mut rng);
+
+        let config = random_config(&mut rng);
+
+        for _ in 0..input_len {
+            input_buf.push(rng.gen());
+        }
+
+        encode_config_buf(&input_buf, config, &mut encoded_buf);
+
+        assert_encode_sanity(&encoded_buf, config, input_len);
+
+        assert_eq!(input_buf, decode_config(&encoded_buf, config).unwrap());
+    }
+}
+
+pub fn random_config<R: Rng>(rng: &mut R) -> Config {
+    const CHARSETS: &[CharacterSet] = &[
+        CharacterSet::UrlSafe,
+        CharacterSet::Standard,
+        CharacterSet::Crypt,
+        CharacterSet::ImapMutf7,
+        CharacterSet::BinHex,
+    ];
+    let charset = *CHARSETS.choose(rng).unwrap();
+
+    Config::new(charset, rng.gen())
+}