From 4bf3e2b90146967b09f5a4397b31bf6161deb234 Mon Sep 17 00:00:00 2001
From: CentricStorm <CentricStorm@users.noreply.github.com>
Date: Mon, 12 Feb 2018 22:12:09 +0000
Subject: [PATCH] Add regular expression lookbehind highlighting.

---
 .../regular expressions (javascript).cson     | 10 ++++---
 spec/javascript-spec.coffee                   | 26 +++++++++++++++++++
 2 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/grammars/regular expressions (javascript).cson b/grammars/regular expressions (javascript).cson
index d9891feb..4ef8a8cc 100644
--- a/grammars/regular expressions (javascript).cson	
+++ b/grammars/regular expressions (javascript).cson	
@@ -43,14 +43,18 @@
         'name': 'keyword.operator.or.regexp'
       }
       {
-        'begin': '(\\()((\\?=)|(\\?!))'
+        'begin': '(\\()(?:(\\?=)|(\\?!)|(\\?<=)|(\\?<!))'
         'beginCaptures':
           '1':
             'name': 'punctuation.definition.group.regexp'
-          '3':
+          '2':
             'name': 'meta.assertion.look-ahead.regexp'
-          '4':
+          '3':
             'name': 'meta.assertion.negative-look-ahead.regexp'
+          '4':
+            'name': 'meta.assertion.look-behind.regexp'
+          '5':
+            'name': 'meta.assertion.negative-look-behind.regexp'
         'end': '(\\))'
         'endCaptures':
           '1':
diff --git a/spec/javascript-spec.coffee b/spec/javascript-spec.coffee
index 6339e3d6..273c9451 100644
--- a/spec/javascript-spec.coffee
+++ b/spec/javascript-spec.coffee
@@ -186,6 +186,32 @@ describe "JavaScript grammar", ->
       expect(tokens[1]).toEqual value: 'test', scopes: ['source.js', 'string.regexp.js']
       expect(tokens[2]).toEqual value: '/', scopes: ['source.js', 'string.regexp.js', 'punctuation.definition.string.end.js']
 
+      {tokens} = grammar.tokenizeLine('/(?<=foo)test(?=bar)/')
+      expect(tokens[0]).toEqual value: '/', scopes: ['source.js', 'string.regexp.js', 'punctuation.definition.string.begin.js']
+      expect(tokens[1]).toEqual value: '(', scopes: ['source.js', 'string.regexp.js', 'meta.group.assertion.regexp', 'punctuation.definition.group.regexp']
+      expect(tokens[2]).toEqual value: '?<=', scopes: ['source.js', 'string.regexp.js', 'meta.group.assertion.regexp', 'meta.assertion.look-behind.regexp']
+      expect(tokens[3]).toEqual value: 'foo', scopes: ['source.js', 'string.regexp.js', 'meta.group.assertion.regexp']
+      expect(tokens[4]).toEqual value: ')', scopes: ['source.js', 'string.regexp.js', 'meta.group.assertion.regexp', 'punctuation.definition.group.regexp']
+      expect(tokens[5]).toEqual value: 'test', scopes: ['source.js', 'string.regexp.js']
+      expect(tokens[6]).toEqual value: '(', scopes: ['source.js', 'string.regexp.js', 'meta.group.assertion.regexp', 'punctuation.definition.group.regexp']
+      expect(tokens[7]).toEqual value: '?=', scopes: ['source.js', 'string.regexp.js', 'meta.group.assertion.regexp', 'meta.assertion.look-ahead.regexp']
+      expect(tokens[8]).toEqual value: 'bar', scopes: ['source.js', 'string.regexp.js', 'meta.group.assertion.regexp']
+      expect(tokens[9]).toEqual value: ')', scopes: ['source.js', 'string.regexp.js', 'meta.group.assertion.regexp', 'punctuation.definition.group.regexp']
+      expect(tokens[10]).toEqual value: '/', scopes: ['source.js', 'string.regexp.js', 'punctuation.definition.string.end.js']
+
+      {tokens} = grammar.tokenizeLine('/(?<!\\$)test(?!\\.)/')
+      expect(tokens[0]).toEqual value: '/', scopes: ['source.js', 'string.regexp.js', 'punctuation.definition.string.begin.js']
+      expect(tokens[1]).toEqual value: '(', scopes: ['source.js', 'string.regexp.js', 'meta.group.assertion.regexp', 'punctuation.definition.group.regexp']
+      expect(tokens[2]).toEqual value: '?<!', scopes: ['source.js', 'string.regexp.js', 'meta.group.assertion.regexp', 'meta.assertion.negative-look-behind.regexp']
+      expect(tokens[3]).toEqual value: '\\$', scopes: ['source.js', 'string.regexp.js', 'meta.group.assertion.regexp', 'constant.character.escape.backslash.regexp']
+      expect(tokens[4]).toEqual value: ')', scopes: ['source.js', 'string.regexp.js', 'meta.group.assertion.regexp', 'punctuation.definition.group.regexp']
+      expect(tokens[5]).toEqual value: 'test', scopes: ['source.js', 'string.regexp.js']
+      expect(tokens[6]).toEqual value: '(', scopes: ['source.js', 'string.regexp.js', 'meta.group.assertion.regexp', 'punctuation.definition.group.regexp']
+      expect(tokens[7]).toEqual value: '?!', scopes: ['source.js', 'string.regexp.js', 'meta.group.assertion.regexp', 'meta.assertion.negative-look-ahead.regexp']
+      expect(tokens[8]).toEqual value: '\\.', scopes: ['source.js', 'string.regexp.js', 'meta.group.assertion.regexp', 'constant.character.escape.backslash.regexp']
+      expect(tokens[9]).toEqual value: ')', scopes: ['source.js', 'string.regexp.js', 'meta.group.assertion.regexp', 'punctuation.definition.group.regexp']
+      expect(tokens[10]).toEqual value: '/', scopes: ['source.js', 'string.regexp.js', 'punctuation.definition.string.end.js']
+
       {tokens} = grammar.tokenizeLine('/{"}/')
       expect(tokens[0]).toEqual value: '/', scopes: ['source.js', 'string.regexp.js', 'punctuation.definition.string.begin.js']
       expect(tokens[2]).toEqual value: '/', scopes: ['source.js', 'string.regexp.js', 'punctuation.definition.string.end.js']