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use {
anyhow::Result,
regex_automata::{
dfa::onepass::{self, DFA},
nfa::thompson,
util::{iter, syntax},
},
regex_test::{
CompiledRegex, Match, RegexTest, SearchKind, Span, TestResult,
TestRunner,
},
};
use crate::{create_input, suite, testify_captures, untestify_kind};
const EXPANSIONS: &[&str] = &["is_match", "find", "captures"];
/// Tests the default configuration of the hybrid NFA/DFA.
#[test]
fn default() -> Result<()> {
let builder = DFA::builder();
TestRunner::new()?
.expand(EXPANSIONS, |t| t.compiles())
.test_iter(suite()?.iter(), compiler(builder))
.assert();
Ok(())
}
/// Tests the hybrid NFA/DFA when 'starts_for_each_pattern' is enabled for all
/// tests.
#[test]
fn starts_for_each_pattern() -> Result<()> {
let mut builder = DFA::builder();
builder.configure(DFA::config().starts_for_each_pattern(true));
TestRunner::new()?
.expand(EXPANSIONS, |t| t.compiles())
.test_iter(suite()?.iter(), compiler(builder))
.assert();
Ok(())
}
/// Tests the hybrid NFA/DFA when byte classes are disabled.
///
/// N.B. Disabling byte classes doesn't avoid any indirection at search time.
/// All it does is cause every byte value to be its own distinct equivalence
/// class.
#[test]
fn no_byte_classes() -> Result<()> {
let mut builder = DFA::builder();
builder.configure(DFA::config().byte_classes(false));
TestRunner::new()?
.expand(EXPANSIONS, |t| t.compiles())
.test_iter(suite()?.iter(), compiler(builder))
.assert();
Ok(())
}
fn compiler(
mut builder: onepass::Builder,
) -> impl FnMut(&RegexTest, &[String]) -> Result<CompiledRegex> {
move |test, regexes| {
// Check if our regex contains things that aren't supported by DFAs.
// That is, Unicode word boundaries when searching non-ASCII text.
if !configure_onepass_builder(test, &mut builder) {
return Ok(CompiledRegex::skip());
}
let re = match builder.build_many(®exes) {
Ok(re) => re,
Err(err) => {
let msg = err.to_string();
// This is pretty gross, but when a regex fails to compile as
// a one-pass regex, then we want to be OK with that and just
// skip the test. But we have to be careful to only skip it
// when the expected result is that the regex compiles. If
// the test is specifically checking that the regex does not
// compile, then we should bubble up that error and allow the
// test to pass.
//
// Since our error types are all generally opaque, we just
// look for an error string. Not great, but not the end of the
// world.
if test.compiles() && msg.contains("not one-pass") {
return Ok(CompiledRegex::skip());
}
return Err(err.into());
}
};
let mut cache = re.create_cache();
Ok(CompiledRegex::compiled(move |test| -> TestResult {
run_test(&re, &mut cache, test)
}))
}
}
fn run_test(
re: &DFA,
cache: &mut onepass::Cache,
test: &RegexTest,
) -> TestResult {
let input = create_input(test);
match test.additional_name() {
"is_match" => {
TestResult::matched(re.is_match(cache, input.earliest(true)))
}
"find" => match test.search_kind() {
SearchKind::Earliest | SearchKind::Leftmost => {
let input =
input.earliest(test.search_kind() == SearchKind::Earliest);
let mut caps = re.create_captures();
let it = iter::Searcher::new(input)
.into_matches_iter(|input| {
re.try_search(cache, input, &mut caps)?;
Ok(caps.get_match())
})
.infallible()
.take(test.match_limit().unwrap_or(std::usize::MAX))
.map(|m| Match {
id: m.pattern().as_usize(),
span: Span { start: m.start(), end: m.end() },
});
TestResult::matches(it)
}
SearchKind::Overlapping => {
// The one-pass DFA does not support any kind of overlapping
// search. This is not just a matter of not having the API.
// It's fundamentally incompatible with the one-pass concept.
// If overlapping matches were possible, then the one-pass DFA
// would fail to build.
TestResult::skip()
}
},
"captures" => match test.search_kind() {
SearchKind::Earliest | SearchKind::Leftmost => {
let input =
input.earliest(test.search_kind() == SearchKind::Earliest);
let it = iter::Searcher::new(input)
.into_captures_iter(re.create_captures(), |input, caps| {
re.try_search(cache, input, caps)
})
.infallible()
.take(test.match_limit().unwrap_or(std::usize::MAX))
.map(|caps| testify_captures(&caps));
TestResult::captures(it)
}
SearchKind::Overlapping => {
// The one-pass DFA does not support any kind of overlapping
// search. This is not just a matter of not having the API.
// It's fundamentally incompatible with the one-pass concept.
// If overlapping matches were possible, then the one-pass DFA
// would fail to build.
TestResult::skip()
}
},
name => TestResult::fail(&format!("unrecognized test name: {}", name)),
}
}
/// Configures the given regex builder with all relevant settings on the given
/// regex test.
///
/// If the regex test has a setting that is unsupported, then this returns
/// false (implying the test should be skipped).
fn configure_onepass_builder(
test: &RegexTest,
builder: &mut onepass::Builder,
) -> bool {
if !test.anchored() {
return false;
}
let match_kind = match untestify_kind(test.match_kind()) {
None => return false,
Some(k) => k,
};
let config = DFA::config().match_kind(match_kind);
builder
.configure(config)
.syntax(config_syntax(test))
.thompson(config_thompson(test));
true
}
/// Configuration of a Thompson NFA compiler from a regex test.
fn config_thompson(test: &RegexTest) -> thompson::Config {
let mut lookm = regex_automata::util::look::LookMatcher::new();
lookm.set_line_terminator(test.line_terminator());
thompson::Config::new().utf8(test.utf8()).look_matcher(lookm)
}
/// Configuration of the regex parser from a regex test.
fn config_syntax(test: &RegexTest) -> syntax::Config {
syntax::Config::new()
.case_insensitive(test.case_insensitive())
.unicode(test.unicode())
.utf8(test.utf8())
.line_terminator(test.line_terminator())
}