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Cleanup common tests
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Signed-off-by: Joe Richey <[email protected]>
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josephlr committed Jun 19, 2024
1 parent fb4f178 commit 4f103bd
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Showing 5 changed files with 123 additions and 133 deletions.
7 changes: 7 additions & 0 deletions src/lib.rs
Original file line number Diff line number Diff line change
Expand Up @@ -404,3 +404,10 @@ pub fn getrandom_uninit(dest: &mut [MaybeUninit<u8>]) -> Result<&mut [u8], Error
// since it returned `Ok`.
Ok(unsafe { slice_assume_init_mut(dest) })
}

// Don't run normal unit tests when testing custom getrandom
#[cfg(all(
test,
not(all(target_family = "wasm", target_os = "unknown", feature = "custom"))
))]
pub(crate) mod tests;
116 changes: 116 additions & 0 deletions src/tests.rs
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@@ -0,0 +1,116 @@
//! Common tests and testing utilities
extern crate std;

use crate::Error;
use std::{mem::MaybeUninit, sync::mpsc, thread, vec, vec::Vec};

#[cfg(feature = "test-in-browser")]
wasm_bindgen_test::wasm_bindgen_test_configure!(run_in_browser);

fn num_diff_bits(s1: &[u8], s2: &[u8]) -> usize {
assert_eq!(s1.len(), s2.len());
s1.iter()
.zip(s2.iter())
.map(|(a, b)| (a ^ b).count_ones() as usize)
.sum()
}

// Type of the functions we want to test
type FillFn<B> = fn(&mut [B]) -> Result<(), Error>;

// Helper trait for testing different `FillFn`s.
pub(crate) trait Byte: Sized + 'static {
fn make_vec(len: usize, fill: FillFn<Self>) -> Vec<u8>;
}
impl Byte for u8 {
fn make_vec(len: usize, fill: FillFn<u8>) -> Vec<u8> {
let mut v = vec![0; len];
fill(&mut v).unwrap();
v
}
}
impl Byte for MaybeUninit<u8> {
fn make_vec(len: usize, fill: FillFn<MaybeUninit<u8>>) -> Vec<u8> {
// Ensure that we always get uninitialized memory.
let mut v = Vec::with_capacity(len);
fill(v.spare_capacity_mut()).unwrap();
unsafe { v.set_len(len) }
v
}
}

// For calls of size `len`, count the number of bits which differ between calls
// and check that between 3 and 5 bits per byte differ. Probability of failure:
// ~ 10^(-30) = 2 * CDF[BinomialDistribution[8*256, 0.5], 3*256]
pub(crate) fn check_bits<B: Byte>(len: usize, fill: FillFn<B>) {
let mut num_bytes = 0;
let mut diff_bits = 0;
while num_bytes < 256 {
let v1 = B::make_vec(len, fill);
let v2 = B::make_vec(len, fill);

num_bytes += len;
diff_bits += num_diff_bits(&v1, &v2);
}

// When the custom feature is enabled, don't check RNG quality.
assert!(diff_bits > 3 * num_bytes);
assert!(diff_bits < 5 * num_bytes);
}

pub(crate) fn check_multithreading<B: Byte>(fill: FillFn<B>) {
let mut txs = vec![];
for _ in 0..20 {
let (tx, rx) = mpsc::channel();
txs.push(tx);

thread::spawn(move || {
// wait until all the tasks are ready to go.
rx.recv().unwrap();
for _ in 0..100 {
check_bits(1000, fill);
thread::yield_now();
}
});
}

// start all the tasks
for tx in txs.iter() {
tx.send(()).unwrap();
}
}

macro_rules! define_tests {
($fill:expr) => {
#[cfg(all(target_family = "wasm", target_os = "unknown",))]
use wasm_bindgen_test::wasm_bindgen_test as test;

#[test]
fn fill_zero() {
$fill(&mut []).unwrap();
}
#[test]
fn fill_small() {
for len in 1..=64 {
crate::tests::check_bits(len, $fill);
}
}
#[test]
fn fill_large() {
crate::tests::check_bits(1_000, $fill);
}
#[test]
fn fill_huge() {
crate::tests::check_bits(1_000_000, $fill);
}
// On WASM, the thread API always fails/panics.
#[test]
#[cfg_attr(target_family = "wasm", ignore)]
fn multithreading() {
crate::tests::check_multithreading($fill)
}
};
}
pub(crate) use define_tests;

define_tests!(crate::getrandom);
100 changes: 0 additions & 100 deletions tests/common/mod.rs

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11 changes: 0 additions & 11 deletions tests/normal.rs

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22 changes: 0 additions & 22 deletions tests/rdrand.rs

This file was deleted.

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