Add re2 quote method for escaping literal patterns

PiperOrigin-RevId: 574927386
Change-Id: Id95fc3f7bbc3da7f4fda06fbdc5b2ed3e4c21ef7

Author: hsudhof

docs/reference.md

@@ -195,6 +195,7 @@
   - [PathAttributes](#pathattributes)
   - [re2](#re2)
     - [re2.compile](#re2compile)
+    - [re2.quote](#re2quote)
   - [re2_matcher](#re2_matcher)
     - [re2_matcher.end](#re2_matcherend)
     - [re2_matcher.find](#re2_matcherfind)
@@ -4762,6 +4763,20 @@ re2.compile("a(.*)b").matches('accccb')
 ```
 
 
+<a id="re2.quote" aria-hidden="true"></a>
+### re2.quote
+
+Quote a string to be matched literally if used within a regex pattern
+
+`string` `re2.quote(string)`
+
+
+#### Parameters:
+
+Parameter | Description
+--------- | -----------
+string | `string`<br><p></p>
+
 
 
 ## re2_matcher

java/com/google/copybara/re2/Re2Module.java

@@ -38,4 +38,13 @@ public class Re2Module implements StarlarkValue {
   public StarlarkPattern compile(String regex) {
     return new StarlarkPattern(Pattern.compile(regex));
   }
+
+  @StarlarkMethod(
+      name = "quote",
+      doc = "Quote a string to be matched literally if used within a regex pattern",
+      parameters = {
+          @Param(name = "string")})
+  public String quote(String string) {
+    return Pattern.quote(string);
+  }
 }

javatests/com/google/copybara/re2/Re2Test.java

@@ -184,4 +184,14 @@ public void replaceAllParam() throws ValidationException {
         + "m.matches()\n"
         + "x = m.replace_all('HELLO$1')")).isEqualTo("HELLObbHELLObbb");
   }
+
+  @Test
+  public void quoteQuotes() throws ValidationException {
+    assertThat(skylark.<Boolean>eval("x", ""
+        + "re = re2.compile('a%s' % (re2.quote('.*')))\n"
+        + "x = re.matcher('axxxxxb').matches()\n")).isFalse();
+    assertThat(skylark.<Boolean>eval("x", ""
+        + "re = re2.compile('a%s' % (re2.quote('.*')))\n"
+        + "x = re.matcher('a.*').matches()\n")).isTrue();
+  }
 }