globset: add 'escape' routine

Fixes #2060, Closes #2061

crates/globset/src/glob.rs

@@ -639,9 +639,9 @@ impl<'a> GlobBuilder<'a> {
     }
 
     /// Toggle whether an empty pattern in a list of alternates is accepted.
-    /// 
+    ///
     /// For example, if this is set then the glob `foo{,.txt}` will match both `foo` and `foo.txt`.
-    /// 
+    ///
     /// By default this is false.
     pub fn empty_alternates(&mut self, yes: bool) -> &mut GlobBuilder<'a> {
         self.opts.empty_alternates = yes;
@@ -1222,12 +1222,20 @@ mod tests {
         Options { casei: Some(true), litsep: None, bsesc: None, ealtre: None };
     const SLASHLIT: Options =
         Options { casei: None, litsep: Some(true), bsesc: None, ealtre: None };
-    const NOBSESC: Options =
-        Options { casei: None, litsep: None, bsesc: Some(false), ealtre: None };
+    const NOBSESC: Options = Options {
+        casei: None,
+        litsep: None,
+        bsesc: Some(false),
+        ealtre: None,
+    };
     const BSESC: Options =
         Options { casei: None, litsep: None, bsesc: Some(true), ealtre: None };
-    const EALTRE: Options =
-        Options { casei: None, litsep: None, bsesc: Some(true), ealtre: Some(true) };
+    const EALTRE: Options = Options {
+        casei: None,
+        litsep: None,
+        bsesc: Some(true),
+        ealtre: Some(true),
+    };
 
     toregex!(re_casei, "a", "(?i)^a$", &CASEI);
 

crates/globset/src/lib.rs

@@ -880,6 +880,29 @@ impl RequiredExtensionStrategyBuilder {
     }
 }
 
+/// Escape meta-characters within the given glob pattern.
+///
+/// The escaping works by surrounding meta-characters with brackets. For
+/// example, `*` becomes `[*]`.
+pub fn escape(s: &str) -> String {
+    let mut escaped = String::with_capacity(s.len());
+    for c in s.chars() {
+        match c {
+            // note that ! does not need escaping because it is only special
+            // inside brackets
+            '?' | '*' | '[' | ']' => {
+                escaped.push('[');
+                escaped.push(c);
+                escaped.push(']');
+            }
+            c => {
+                escaped.push(c);
+            }
+        }
+    }
+    escaped
+}
+
 #[cfg(test)]
 mod tests {
     use super::{GlobSet, GlobSetBuilder};
@@ -919,4 +942,16 @@ mod tests {
         assert!(!set.is_match(""));
         assert!(!set.is_match("a"));
     }
+
+    #[test]
+    fn escape() {
+        use super::escape;
+        assert_eq!("foo", escape("foo"));
+        assert_eq!("foo[*]", escape("foo*"));
+        assert_eq!("[[][]]", escape("[]"));
+        assert_eq!("[*][?]", escape("*?"));
+        assert_eq!("src/[*][*]/[*].rs", escape("src/**/*.rs"));
+        assert_eq!("bar[[]ab[]]baz", escape("bar[ab]baz"));
+        assert_eq!("bar[[]!![]]!baz", escape("bar[!!]!baz"));
+    }
 }