summaryrefslogtreecommitdiffstats
path: root/vendor/regex-automata/tests/hybrid/api.rs
diff options
context:
space:
mode:
Diffstat (limited to 'vendor/regex-automata/tests/hybrid/api.rs')
-rw-r--r--vendor/regex-automata/tests/hybrid/api.rs195
1 files changed, 195 insertions, 0 deletions
diff --git a/vendor/regex-automata/tests/hybrid/api.rs b/vendor/regex-automata/tests/hybrid/api.rs
new file mode 100644
index 000000000..9a834dbb8
--- /dev/null
+++ b/vendor/regex-automata/tests/hybrid/api.rs
@@ -0,0 +1,195 @@
+use std::error::Error;
+
+use regex_automata::{
+ hybrid::{
+ dfa::{self, DFA},
+ regex::Regex,
+ OverlappingState,
+ },
+ nfa::thompson,
+ HalfMatch, MatchError, MatchKind, MultiMatch,
+};
+
+use crate::util::{BunkPrefilter, SubstringPrefilter};
+
+// Tests that too many cache resets cause the lazy DFA to quit.
+//
+// We only test this on 64-bit because the test is gingerly crafted based on
+// implementation details of cache sizes. It's not a great test because of
+// that, but it does check some interesting properties around how positions are
+// reported when a search "gives up."
+#[test]
+#[cfg(target_pointer_width = "64")]
+fn too_many_cache_resets_cause_quit() -> Result<(), Box<dyn Error>> {
+ // This is a carefully chosen regex. The idea is to pick one that requires
+ // some decent number of states (hence the bounded repetition). But we
+ // specifically choose to create a class with an ASCII letter and a
+ // non-ASCII letter so that we can check that no new states are created
+ // once the cache is full. Namely, if we fill up the cache on a haystack
+ // of 'a's, then in order to match one 'β', a new state will need to be
+ // created since a 'β' is encoded with multiple bytes. Since there's no
+ // room for this state, the search should quit at the very first position.
+ let pattern = r"[aβ]{100}";
+ let dfa = DFA::builder()
+ .configure(
+ // Configure it so that we have the minimum cache capacity
+ // possible. And that if any resets occur, the search quits.
+ DFA::config()
+ .skip_cache_capacity_check(true)
+ .cache_capacity(0)
+ .minimum_cache_clear_count(Some(0)),
+ )
+ .build(pattern)?;
+ let mut cache = dfa.create_cache();
+
+ let haystack = "a".repeat(101).into_bytes();
+ let err = MatchError::GaveUp { offset: 25 };
+ assert_eq!(dfa.find_earliest_fwd(&mut cache, &haystack), Err(err.clone()));
+ assert_eq!(dfa.find_leftmost_fwd(&mut cache, &haystack), Err(err.clone()));
+ assert_eq!(
+ dfa.find_overlapping_fwd(
+ &mut cache,
+ &haystack,
+ &mut OverlappingState::start()
+ ),
+ Err(err.clone())
+ );
+
+ let haystack = "β".repeat(101).into_bytes();
+ let err = MatchError::GaveUp { offset: 0 };
+ assert_eq!(dfa.find_earliest_fwd(&mut cache, &haystack), Err(err));
+ // no need to test that other find routines quit, since we did that above
+
+ // OK, if we reset the cache, then we should be able to create more states
+ // and make more progress with searching for betas.
+ cache.reset(&dfa);
+ let err = MatchError::GaveUp { offset: 26 };
+ assert_eq!(dfa.find_earliest_fwd(&mut cache, &haystack), Err(err));
+
+ // ... switching back to ASCII still makes progress since it just needs to
+ // set transitions on existing states!
+ let haystack = "a".repeat(101).into_bytes();
+ let err = MatchError::GaveUp { offset: 13 };
+ assert_eq!(dfa.find_earliest_fwd(&mut cache, &haystack), Err(err));
+
+ Ok(())
+}
+
+// Tests that quit bytes in the forward direction work correctly.
+#[test]
+fn quit_fwd() -> Result<(), Box<dyn Error>> {
+ let dfa = DFA::builder()
+ .configure(DFA::config().quit(b'x', true))
+ .build("[[:word:]]+$")?;
+ let mut cache = dfa.create_cache();
+
+ assert_eq!(
+ dfa.find_earliest_fwd(&mut cache, b"abcxyz"),
+ Err(MatchError::Quit { byte: b'x', offset: 3 })
+ );
+ assert_eq!(
+ dfa.find_leftmost_fwd(&mut cache, b"abcxyz"),
+ Err(MatchError::Quit { byte: b'x', offset: 3 })
+ );
+ assert_eq!(
+ dfa.find_overlapping_fwd(
+ &mut cache,
+ b"abcxyz",
+ &mut OverlappingState::start()
+ ),
+ Err(MatchError::Quit { byte: b'x', offset: 3 })
+ );
+
+ Ok(())
+}
+
+// Tests that quit bytes in the reverse direction work correctly.
+#[test]
+fn quit_rev() -> Result<(), Box<dyn Error>> {
+ let dfa = DFA::builder()
+ .configure(DFA::config().quit(b'x', true))
+ .thompson(thompson::Config::new().reverse(true))
+ .build("^[[:word:]]+")?;
+ let mut cache = dfa.create_cache();
+
+ assert_eq!(
+ dfa.find_earliest_rev(&mut cache, b"abcxyz"),
+ Err(MatchError::Quit { byte: b'x', offset: 3 })
+ );
+ assert_eq!(
+ dfa.find_leftmost_rev(&mut cache, b"abcxyz"),
+ Err(MatchError::Quit { byte: b'x', offset: 3 })
+ );
+
+ Ok(())
+}
+
+// Tests that if we heuristically enable Unicode word boundaries but then
+// instruct that a non-ASCII byte should NOT be a quit byte, then the builder
+// will panic.
+#[test]
+#[should_panic]
+fn quit_panics() {
+ DFA::config().unicode_word_boundary(true).quit(b'\xFF', false);
+}
+
+// This tests an intesting case where even if the Unicode word boundary option
+// is disabled, setting all non-ASCII bytes to be quit bytes will cause Unicode
+// word boundaries to be enabled.
+#[test]
+fn unicode_word_implicitly_works() -> Result<(), Box<dyn Error>> {
+ let mut config = DFA::config();
+ for b in 0x80..=0xFF {
+ config = config.quit(b, true);
+ }
+ let dfa = DFA::builder().configure(config).build(r"\b")?;
+ let mut cache = dfa.create_cache();
+ let expected = HalfMatch::must(0, 1);
+ assert_eq!(dfa.find_leftmost_fwd(&mut cache, b" a"), Ok(Some(expected)));
+ Ok(())
+}
+
+// Tests that we can provide a prefilter to a Regex, and the search reports
+// correct results.
+#[test]
+fn prefilter_works() -> Result<(), Box<dyn Error>> {
+ let mut re = Regex::new(r"a[0-9]+").unwrap();
+ re.set_prefilter(Some(Box::new(SubstringPrefilter::new("a"))));
+ let mut cache = re.create_cache();
+
+ let text = b"foo abc foo a1a2a3 foo a123 bar aa456";
+ let matches: Vec<(usize, usize)> = re
+ .find_leftmost_iter(&mut cache, text)
+ .map(|m| (m.start(), m.end()))
+ .collect();
+ assert_eq!(
+ matches,
+ vec![(12, 14), (14, 16), (16, 18), (23, 27), (33, 37),]
+ );
+ Ok(())
+}
+
+// This test confirms that a prefilter is active by using a prefilter that
+// reports false negatives.
+#[test]
+fn prefilter_is_active() -> Result<(), Box<dyn Error>> {
+ let text = b"za123";
+ let mut re = Regex::new(r"a[0-9]+").unwrap();
+ let mut cache = re.create_cache();
+
+ re.set_prefilter(Some(Box::new(SubstringPrefilter::new("a"))));
+ assert_eq!(
+ re.find_leftmost(&mut cache, b"za123"),
+ Some(MultiMatch::must(0, 1, 5))
+ );
+ assert_eq!(
+ re.find_leftmost(&mut cache, b"a123"),
+ Some(MultiMatch::must(0, 0, 4))
+ );
+ re.set_prefilter(Some(Box::new(BunkPrefilter::new())));
+ assert_eq!(re.find_leftmost(&mut cache, b"za123"), None);
+ // This checks that the prefilter is used when first starting the search,
+ // instead of waiting until at least one transition has occurred.
+ assert_eq!(re.find_leftmost(&mut cache, b"a123"), None);
+ Ok(())
+}