Vendor things

third-party/vendor/regex/tests/suite_bytes.rs

@@ -0,0 +1,108 @@
+use {
+    anyhow::Result,
+    regex::bytes::{Regex, RegexBuilder},
+    regex_test::{
+        CompiledRegex, Match, RegexTest, Span, TestResult, TestRunner,
+    },
+};
+
+/// Tests the default configuration of the hybrid NFA/DFA.
+#[test]
+fn default() -> Result<()> {
+    let mut runner = TestRunner::new()?;
+    runner
+        .expand(&["is_match", "find", "captures"], |test| test.compiles())
+        .blacklist_iter(super::BLACKLIST)
+        .test_iter(crate::suite()?.iter(), compiler)
+        .assert();
+    Ok(())
+}
+
+fn run_test(re: &Regex, test: &RegexTest) -> TestResult {
+    match test.additional_name() {
+        "is_match" => TestResult::matched(re.is_match(test.haystack())),
+        "find" => TestResult::matches(
+            re.find_iter(test.haystack())
+                .take(test.match_limit().unwrap_or(std::usize::MAX))
+                .map(|m| Match {
+                    id: 0,
+                    span: Span { start: m.start(), end: m.end() },
+                }),
+        ),
+        "captures" => {
+            let it = re
+                .captures_iter(test.haystack())
+                .take(test.match_limit().unwrap_or(std::usize::MAX))
+                .map(|caps| testify_captures(&caps));
+            TestResult::captures(it)
+        }
+        name => TestResult::fail(&format!("unrecognized test name: {}", name)),
+    }
+}
+
+/// Converts the given regex test to a closure that searches with a
+/// `bytes::Regex`. If the test configuration is unsupported, then a
+/// `CompiledRegex` that skips the test is returned.
+fn compiler(
+    test: &RegexTest,
+    _patterns: &[String],
+) -> anyhow::Result<CompiledRegex> {
+    let skip = Ok(CompiledRegex::skip());
+
+    // We're only testing bytes::Regex here, which supports one pattern only.
+    let pattern = match test.regexes().len() {
+        1 => &test.regexes()[0],
+        _ => return skip,
+    };
+    // We only test is_match, find_iter and captures_iter. All of those are
+    // leftmost searches.
+    if !matches!(test.search_kind(), regex_test::SearchKind::Leftmost) {
+        return skip;
+    }
+    // The top-level single-pattern regex API always uses leftmost-first.
+    if !matches!(test.match_kind(), regex_test::MatchKind::LeftmostFirst) {
+        return skip;
+    }
+    // The top-level regex API always runs unanchored searches. ... But we can
+    // handle tests that are anchored but have only one match.
+    if test.anchored() && test.match_limit() != Some(1) {
+        return skip;
+    }
+    // We don't support tests with explicit search bounds. We could probably
+    // support this by using the 'find_at' (and such) APIs.
+    let bounds = test.bounds();
+    if !(bounds.start == 0 && bounds.end == test.haystack().len()) {
+        return skip;
+    }
+    // The bytes::Regex API specifically does not support enabling UTF-8 mode.
+    // It could I suppose, but currently it does not. That is, it permits
+    // matches to have offsets that split codepoints.
+    if test.utf8() {
+        return skip;
+    }
+    // If the test requires Unicode but the Unicode feature isn't enabled,
+    // skip it. This is a little aggressive, but the test suite doesn't
+    // have any easy way of communicating which Unicode features are needed.
+    if test.unicode() && !cfg!(feature = "unicode") {
+        return skip;
+    }
+    let re = RegexBuilder::new(pattern)
+        .case_insensitive(test.case_insensitive())
+        .unicode(test.unicode())
+        .line_terminator(test.line_terminator())
+        .build()?;
+    Ok(CompiledRegex::compiled(move |test| run_test(&re, test)))
+}
+
+/// Convert `Captures` into the test suite's capture values.
+fn testify_captures(
+    caps: &regex::bytes::Captures<'_>,
+) -> regex_test::Captures {
+    let spans = caps.iter().map(|group| {
+        group.map(|m| regex_test::Span { start: m.start(), end: m.end() })
+    });
+    // This unwrap is OK because we assume our 'caps' represents a match, and
+    // a match always gives a non-zero number of groups with the first group
+    // being non-None.
+    regex_test::Captures::new(0, spans).unwrap()
+}