1 files changed, 117 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..7083b5433f
--- /dev/null
+++ b/third_party/rust/base64/src/tests.rs
@@ -0,0 +1,117 @@
+use std::str;
+
+use rand::{
+    distributions,
+    distributions::{Distribution as _, Uniform},
+    seq::SliceRandom,
+    Rng, SeedableRng,
+};
+
+use crate::{
+    alphabet,
+    encode::encoded_len,
+    engine::{
+        general_purpose::{GeneralPurpose, GeneralPurposeConfig},
+        Config, DecodePaddingMode, Engine,
+    },
+};
+
+#[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, padded: bool, input_len: usize) {
+    let input_rem = input_len % 3;
+    let expected_padding_len = if input_rem > 0 {
+        if padded {
+            3 - input_rem
+        } else {
+            0
+        }
+    } else {
+        0
+    };
+
+    let expected_encoded_len = encoded_len(input_len, padded).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 engine = random_engine(&mut rng);
+
+        for _ in 0..input_len {
+            input_buf.push(rng.gen());
+        }
+
+        engine.encode_string(&input_buf, &mut encoded_buf);
+
+        assert_encode_sanity(&encoded_buf, engine.config().encode_padding(), input_len);
+
+        assert_eq!(input_buf, engine.decode(&encoded_buf).unwrap());
+    }
+}
+
+pub fn random_config<R: Rng>(rng: &mut R) -> GeneralPurposeConfig {
+    let mode = rng.gen();
+    GeneralPurposeConfig::new()
+        .with_encode_padding(match mode {
+            DecodePaddingMode::Indifferent => rng.gen(),
+            DecodePaddingMode::RequireCanonical => true,
+            DecodePaddingMode::RequireNone => false,
+        })
+        .with_decode_padding_mode(mode)
+        .with_decode_allow_trailing_bits(rng.gen())
+}
+
+impl distributions::Distribution<DecodePaddingMode> for distributions::Standard {
+    fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> DecodePaddingMode {
+        match rng.gen_range(0..=2) {
+            0 => DecodePaddingMode::Indifferent,
+            1 => DecodePaddingMode::RequireCanonical,
+            _ => DecodePaddingMode::RequireNone,
+        }
+    }
+}
+
+pub fn random_alphabet<R: Rng>(rng: &mut R) -> &'static alphabet::Alphabet {
+    ALPHABETS.choose(rng).unwrap()
+}
+
+pub fn random_engine<R: Rng>(rng: &mut R) -> GeneralPurpose {
+    let alphabet = random_alphabet(rng);
+    let config = random_config(rng);
+    GeneralPurpose::new(alphabet, config)
+}
+
+const ALPHABETS: &[alphabet::Alphabet] = &[
+    alphabet::URL_SAFE,
+    alphabet::STANDARD,
+    alphabet::CRYPT,
+    alphabet::BCRYPT,
+    alphabet::IMAP_MUTF7,
+    alphabet::BIN_HEX,
+];