Fix regex termination lexer (#623)

src/parser.js

@@ -76,9 +76,23 @@ const parser = (() => {
  var depth = 0;
  var pattern;
  var flags;
+
+ var isClosingSlash = function (position) {
+ if (path.charAt(position) === '/' && depth === 0) {
+ var backslashCount = 0;
+ while (path.charAt(position - (backslashCount + 1)) === '\\') {
+ backslashCount++;
+ }
+ if (backslashCount % 2 === 0) {
+ return true;
+ }
+ }
+ return false;
+ };
+
  while (position < length) {
  var currentChar = path.charAt(position);
- if (currentChar === '/' && path.charAt(position - 1) !== '\\' && depth === 0) {
+ if (isClosingSlash(position)) {
  // end of regex found
  pattern = path.substring(start, position);
  if (pattern === '') {

test/implementation-tests.js

@@ -749,7 +749,38 @@ describe("Tests that are specific to a Javascript runtime", () => {
  });
  });
 
+ describe("empty regex: Escaped termination", function() {
+ it("should throw error", function() {
+ expect(function() {
+ var expr = jsonata("/\\/");
+ expr.evaluate();
+ })
+ .to.throw()
+ .to.deep.contain({ position: 3, code: "S0302" });
+ });
+ });
+
+ describe("empty regex: Escaped termination", function() {
+ it("should throw error", function() {
+ expect(function() {
+ var expr = jsonata("/\\\\\\/");
+ expr.evaluate();
+ })
+ .to.throw()
+ .to.deep.contain({ position: 5, code: "S0302" });
+ });
+ });
+
  describe("Functions - $match", function() {
+ describe('$match("test escape \\\\", /\\\\/)', function() {
+ it("should find \\", async function() {
+ var expr = jsonata('$match("test escape \\\\", /\\\\/)');
+ var result = await expr.evaluate();
+ var expected = { match: "\\", index: 12, groups: []};
+ expect(result).to.deep.equal(expected);
+ });
+ });
+
  describe('$match("ababbabbcc",/ab/)', function() {
  it("should return result object", async function() {
  var expr = jsonata('$match("ababbabbcc",/ab/)');