1 files changed, 82 insertions, 0 deletions
diff --git a/src/tools/clippy/tests/ui/regex.rs b/src/tools/clippy/tests/ui/regex.rs
new file mode 100644
index 000000000..f7f3b195c
--- /dev/null
+++ b/src/tools/clippy/tests/ui/regex.rs
@@ -0,0 +1,82 @@
+#![allow(unused)]
+#![warn(clippy::invalid_regex, clippy::trivial_regex)]
+
+extern crate regex;
+
+use regex::bytes::{Regex as BRegex, RegexBuilder as BRegexBuilder, RegexSet as BRegexSet};
+use regex::{Regex, RegexBuilder, RegexSet};
+
+const OPENING_PAREN: &str = "(";
+const NOT_A_REAL_REGEX: &str = "foobar";
+
+fn syntax_error() {
+    let pipe_in_wrong_position = Regex::new("|");
+    let pipe_in_wrong_position_builder = RegexBuilder::new("|");
+    let wrong_char_ranice = Regex::new("[z-a]");
+    let some_unicode = Regex::new("[é-è]");
+
+    let some_regex = Regex::new(OPENING_PAREN);
+
+    let binary_pipe_in_wrong_position = BRegex::new("|");
+    let some_binary_regex = BRegex::new(OPENING_PAREN);
+    let some_binary_regex_builder = BRegexBuilder::new(OPENING_PAREN);
+
+    let closing_paren = ")";
+    let not_linted = Regex::new(closing_paren);
+
+    let set = RegexSet::new(&[r"[a-z]+@[a-z]+\.(com|org|net)", r"[a-z]+\.(com|org|net)"]);
+    let bset = BRegexSet::new(&[
+        r"[a-z]+@[a-z]+\.(com|org|net)",
+        r"[a-z]+\.(com|org|net)",
+        r".", // regression test
+    ]);
+
+    let set_error = RegexSet::new(&[OPENING_PAREN, r"[a-z]+\.(com|org|net)"]);
+    let bset_error = BRegexSet::new(&[OPENING_PAREN, r"[a-z]+\.(com|org|net)"]);
+
+    let raw_string_error = Regex::new(r"[...\/...]");
+    let raw_string_error = Regex::new(r#"[...\/...]"#);
+}
+
+fn trivial_regex() {
+    let trivial_eq = Regex::new("^foobar$");
+
+    let trivial_eq_builder = RegexBuilder::new("^foobar$");
+
+    let trivial_starts_with = Regex::new("^foobar");
+
+    let trivial_ends_with = Regex::new("foobar$");
+
+    let trivial_contains = Regex::new("foobar");
+
+    let trivial_contains = Regex::new(NOT_A_REAL_REGEX);
+
+    let trivial_backslash = Regex::new("a\\.b");
+
+    // unlikely corner cases
+    let trivial_empty = Regex::new("");
+
+    let trivial_empty = Regex::new("^");
+
+    let trivial_empty = Regex::new("^$");
+
+    let binary_trivial_empty = BRegex::new("^$");
+
+    // non-trivial regexes
+    let non_trivial_dot = Regex::new("a.b");
+    let non_trivial_dot_builder = RegexBuilder::new("a.b");
+    let non_trivial_eq = Regex::new("^foo|bar$");
+    let non_trivial_starts_with = Regex::new("^foo|bar");
+    let non_trivial_ends_with = Regex::new("^foo|bar");
+    let non_trivial_ends_with = Regex::new("foo|bar");
+    let non_trivial_binary = BRegex::new("foo|bar");
+    let non_trivial_binary_builder = BRegexBuilder::new("foo|bar");
+
+    // #6005: unicode classes in bytes::Regex
+    let a_byte_of_unicode = BRegex::new(r"\p{C}");
+}
+
+fn main() {
+    syntax_error();
+    trivial_regex();
+}