Merge 1033d7b into 8894cd9

CHANGELOG.md

@@ -1,3 +1,7 @@
+## version 1.16.0 (2020-08-25)
+
+- Fixes `flags(regexp)` to work in older browsers (Edge versions 15-18), which fixes crashes on startup in those old clients
+
 ## version 1.15.0 (2020-07-27)
 
 - Adds support for the `s` (`dotAll`) flag in `Parsimmon.regexp`

src/parsimmon.js

@@ -694,8 +694,17 @@ function formatError(input, error) {
 }
 
 function flags(re) {
-  var s = "" + re;
-  return s.slice(s.lastIndexOf("/") + 1);
+  if (re.flags !== undefined) {
+    return re.flags;
+  }
+  // legacy browser support
+  return [
+    re.global ? "g" : "",
+    re.ignoreCase ? "i" : "",
+    re.multiline ? "m" : "",
+    re.unicode ? "u" : "",
+    re.sticky ? "y" : ""
+  ].join("");
 }
 
 function anchoredRegexp(re) {

test/.eslintrc

@@ -7,5 +7,8 @@
     "Parsimmon": true,
     "assert": true,
     "testSetScenario": true
+  },
+  "rules": {
+    "no-invalid-regexp": ["error", {"allowConstructorFlags": ["u", "y"]}]
   }
 }

test/core/flags.test.js

@@ -0,0 +1,72 @@
+"use strict";
+
+testSetScenario(function() {
+  describe("flags()", function() {
+    it("works in modern browsers", function() {
+      assert.throws(function() {
+        Parsimmon.regexp(new RegExp("a", "g"));
+      });
+      assert.doesNotThrow(function() {
+        Parsimmon.regexp(new RegExp("a", "i"));
+      });
+      assert.doesNotThrow(function() {
+        Parsimmon.regexp(new RegExp("a", "m"));
+      });
+      assert.doesNotThrow(function() {
+        Parsimmon.regexp(new RegExp("a", "u"));
+      });
+      assert.throws(function() {
+        Parsimmon.regexp(new RegExp("a", "y"));
+      });
+    });
+
+    it("works on legacy browsers without Regexp.flags property with flags", function() {
+      var oldRegExpG = new RegExp("a", "g");
+      var oldRegExpI = new RegExp("a", "i");
+      var oldRegExpM = new RegExp("a", "m");
+      var oldRegExpU = new RegExp("a", "u");
+      var oldRegExpY = new RegExp("a", "y");
+      var oldRegExps = [
+        oldRegExpG,
+        oldRegExpI,
+        oldRegExpM,
+        oldRegExpU,
+        oldRegExpY
+      ];
+
+      // Simulate old RegExp without the flags property
+      oldRegExps.map(function(r) {
+        Object.defineProperty(r, "flags", { value: undefined });
+        assert.strictEqual(r.flags, undefined);
+      });
+
+      assert.throws(function() {
+        Parsimmon.regexp(oldRegExpG);
+      });
+      assert.doesNotThrow(function() {
+        Parsimmon.regexp(oldRegExpI);
+      });
+      assert.doesNotThrow(function() {
+        Parsimmon.regexp(oldRegExpM);
+      });
+      assert.doesNotThrow(function() {
+        Parsimmon.regexp(oldRegExpU);
+      });
+      assert.throws(function() {
+        Parsimmon.regexp(oldRegExpY);
+      });
+    });
+
+    it("works on legacy browsers without Regexp.flags property without flags", function() {
+      var oldRegExp = new RegExp("a", "");
+
+      // Simulate old RegExp without the flags property
+      Object.defineProperty(oldRegExp, "flags", { value: undefined });
+      assert.strictEqual(oldRegExp.flags, undefined);
+
+      assert.doesNotThrow(function() {
+        Parsimmon.regexp(oldRegExp);
+      });
+    });
+  });
+});