From 7a510b2c6a399aa710a7511d932b1b8e1c886054 Mon Sep 17 00:00:00 2001
From: Jack Wrenn <jack@wrenn.fyi>
Date: Sat, 29 Jun 2024 10:33:55 +0000
Subject: [PATCH] ci: Run most tests with miri

This PR additionally reduces the size of some heavy tests to
reduce their running time. We use nextest as our runner because it
runs tests in parallel. However, since nextest does not currenlty
run doc tests, we also run those separately.
---
 .github/workflows/ci.yml | 15 +++++++++++++++
 tests/quick.rs           |  4 ++++
 tests/specializations.rs |  7 +++++++
 tests/test_std.rs        | 20 ++++++++++++--------
 4 files changed, 38 insertions(+), 8 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 4b8dcf189..8e2a9d66c 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -54,6 +54,21 @@ jobs:
       - uses: dtolnay/rust-toolchain@stable
       - run: cargo test --all-features
 
+  miri:
+    runs-on: ubuntu-latest
+    env:
+      CARGO_TERM_COLOR: always
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@master
+        with:
+          toolchain: nightly
+          components: miri
+      - uses: taiki-e/install-action@nextest
+      - run: |
+          cargo miri nextest run --all-features
+          cargo miri test --doc
+
   check-format:
     name: check format
     runs-on: ubuntu-latest
diff --git a/tests/quick.rs b/tests/quick.rs
index 12b6b9d5a..672901e7c 100644
--- a/tests/quick.rs
+++ b/tests/quick.rs
@@ -2,7 +2,11 @@
 //! and adaptors.
 //!
 //! In particular we test the tedious size_hint and exact size correctness.
+//!
+//! **NOTE:** Due to performance limitations, these tests are not run with miri!
+//! They cannot be relied upon to discover soundness issues.
 
+#![cfg(not(miri))]
 #![allow(deprecated, unstable_name_collisions)]
 
 use itertools::free::{
diff --git a/tests/specializations.rs b/tests/specializations.rs
index ff3d5c19b..3e4831024 100644
--- a/tests/specializations.rs
+++ b/tests/specializations.rs
@@ -1,3 +1,10 @@
+//! Test specializations of methods with default impls match the behavior of the
+//! default impls.
+//!
+//! **NOTE:** Due to performance limitations, these tests are not run with miri!
+//! They cannot be relied upon to discover soundness issues.
+
+#![cfg(not(miri))]
 #![allow(unstable_name_collisions)]
 
 use itertools::Itertools;
diff --git a/tests/test_std.rs b/tests/test_std.rs
index 00246d506..f626a17d7 100644
--- a/tests/test_std.rs
+++ b/tests/test_std.rs
@@ -491,6 +491,7 @@ fn sorted_by() {
     it::assert_equal(v, vec![4, 3, 2, 1, 0]);
 }
 
+#[cfg(not(miri))]
 qc::quickcheck! {
     fn k_smallest_range(n: i64, m: u16, k: u16) -> () {
         // u16 is used to constrain k and m to 0..2¹⁶,
@@ -598,7 +599,9 @@ macro_rules! generic_test {
     };
 }
 
+#[cfg(not(miri))]
 generic_test!(k_smallest_sort, u8, u16, u32, u64, i8, i16, i32, i64);
+#[cfg(not(miri))]
 generic_test!(k_smallest_by_sort, u8, u16, u32, u64, i8, i16, i32, i64);
 
 #[test]
@@ -1055,8 +1058,8 @@ fn binomial(n: usize, k: usize) -> usize {
 
 #[test]
 fn combinations_range_count() {
-    for n in 0..=10 {
-        for k in 0..=10 {
+    for n in 0..=7 {
+        for k in 0..=7 {
             let len = binomial(n, k);
             let mut it = (0..n).combinations(k);
             assert_eq!(len, it.clone().count());
@@ -1077,7 +1080,7 @@ fn combinations_range_count() {
 
 #[test]
 fn combinations_inexact_size_hints() {
-    for k in 0..=10 {
+    for k in 0..=7 {
         let mut numbers = (0..18).filter(|i| i % 2 == 0); // 9 elements
         let mut it = numbers.clone().combinations(k);
         let real_n = numbers.clone().count();
@@ -1129,8 +1132,8 @@ fn permutations_zero() {
 
 #[test]
 fn permutations_range_count() {
-    for n in 0..=7 {
-        for k in 0..=7 {
+    for n in 0..=4 {
+        for k in 0..=4 {
             let len = if k <= n { (n - k + 1..=n).product() } else { 0 };
             let mut it = (0..n).permutations(k);
             assert_eq!(len, it.clone().count());
@@ -1162,6 +1165,7 @@ fn permutations_overflowed_size_hints() {
 }
 
 #[test]
+#[cfg(not(miri))]
 fn combinations_with_replacement() {
     // Pool smaller than n
     it::assert_equal((0..1).combinations_with_replacement(2), vec![vec![0, 0]]);
@@ -1190,8 +1194,8 @@ fn combinations_with_replacement() {
 
 #[test]
 fn combinations_with_replacement_range_count() {
-    for n in 0..=7 {
-        for k in 0..=7 {
+    for n in 0..=4 {
+        for k in 0..=4 {
             let len = binomial(usize::saturating_sub(n + k, 1), k);
             let mut it = (0..n).combinations_with_replacement(k);
             assert_eq!(len, it.clone().count());
@@ -1236,7 +1240,7 @@ fn powerset() {
     assert_eq!((0..8).powerset().count(), 1 << 8);
     assert_eq!((0..16).powerset().count(), 1 << 16);
 
-    for n in 0..=10 {
+    for n in 0..=4 {
         let mut it = (0..n).powerset();
         let len = 2_usize.pow(n);
         assert_eq!(len, it.clone().count());