1 files changed, 126 insertions, 0 deletions
diff --git a/vendor/memchr/src/tests/substring/prop.rs b/vendor/memchr/src/tests/substring/prop.rs
new file mode 100644
index 000000000..a8352ec74
--- /dev/null
+++ b/vendor/memchr/src/tests/substring/prop.rs
@@ -0,0 +1,126 @@
+/*!
+This module defines a few quickcheck properties for substring search.
+
+It also provides a forward and reverse macro for conveniently defining
+quickcheck tests that run these properties over any substring search
+implementation.
+*/
+
+use crate::tests::substring::naive;
+
+/// $fwd is a `impl FnMut(haystack, needle) -> Option<Option<usize>>`. When the
+/// routine returns `None`, then it's skipped, which is useful for substring
+/// implementations that don't work for all inputs.
+#[macro_export]
+macro_rules! define_substring_forward_quickcheck {
+    ($fwd:expr) => {
+        #[cfg(not(miri))]
+        quickcheck::quickcheck! {
+            fn qc_fwd_prefix_is_substring(bs: alloc::vec::Vec<u8>) -> bool {
+                crate::tests::substring::prop::prefix_is_substring(&bs, $fwd)
+            }
+
+            fn qc_fwd_suffix_is_substring(bs: alloc::vec::Vec<u8>) -> bool {
+                crate::tests::substring::prop::suffix_is_substring(&bs, $fwd)
+            }
+
+            fn qc_fwd_matches_naive(
+                haystack: alloc::vec::Vec<u8>,
+                needle: alloc::vec::Vec<u8>
+            ) -> bool {
+                crate::tests::substring::prop::same_as_naive(
+                    false,
+                    &haystack,
+                    &needle,
+                    $fwd,
+                )
+            }
+        }
+    };
+}
+
+/// $rev is a `impl FnMut(haystack, needle) -> Option<Option<usize>>`. When the
+/// routine returns `None`, then it's skipped, which is useful for substring
+/// implementations that don't work for all inputs.
+#[macro_export]
+macro_rules! define_substring_reverse_quickcheck {
+    ($rev:expr) => {
+        #[cfg(not(miri))]
+        quickcheck::quickcheck! {
+            fn qc_rev_prefix_is_substring(bs: alloc::vec::Vec<u8>) -> bool {
+                crate::tests::substring::prop::prefix_is_substring(&bs, $rev)
+            }
+
+            fn qc_rev_suffix_is_substring(bs: alloc::vec::Vec<u8>) -> bool {
+                crate::tests::substring::prop::suffix_is_substring(&bs, $rev)
+            }
+
+            fn qc_rev_matches_naive(
+                haystack: alloc::vec::Vec<u8>,
+                needle: alloc::vec::Vec<u8>
+            ) -> bool {
+                crate::tests::substring::prop::same_as_naive(
+                    true,
+                    &haystack,
+                    &needle,
+                    $rev,
+                )
+            }
+        }
+    };
+}
+
+/// Check that every prefix of the given byte string is a substring.
+pub(crate) fn prefix_is_substring(
+    bs: &[u8],
+    mut search: impl FnMut(&[u8], &[u8]) -> Option<Option<usize>>,
+) -> bool {
+    for i in 0..bs.len().saturating_sub(1) {
+        let prefix = &bs[..i];
+        let result = match search(bs, prefix) {
+            None => continue,
+            Some(result) => result,
+        };
+        if !result.is_some() {
+            return false;
+        }
+    }
+    true
+}
+
+/// Check that every suffix of the given byte string is a substring.
+pub(crate) fn suffix_is_substring(
+    bs: &[u8],
+    mut search: impl FnMut(&[u8], &[u8]) -> Option<Option<usize>>,
+) -> bool {
+    for i in 0..bs.len().saturating_sub(1) {
+        let suffix = &bs[i..];
+        let result = match search(bs, suffix) {
+            None => continue,
+            Some(result) => result,
+        };
+        if !result.is_some() {
+            return false;
+        }
+    }
+    true
+}
+
+/// Check that naive substring search matches the result of the given search
+/// algorithm.
+pub(crate) fn same_as_naive(
+    reverse: bool,
+    haystack: &[u8],
+    needle: &[u8],
+    mut search: impl FnMut(&[u8], &[u8]) -> Option<Option<usize>>,
+) -> bool {
+    let result = match search(haystack, needle) {
+        None => return true,
+        Some(result) => result,
+    };
+    if reverse {
+        result == naive::rfind(haystack, needle)
+    } else {
+        result == naive::find(haystack, needle)
+    }
+}