From eed510ce355ba82834ed082bcd27bb5bbb080c2a Mon Sep 17 00:00:00 2001
From: Vincent Thibault <vthibault@users.noreply.github.com>
Date: Sun, 16 Feb 2020 14:32:10 +0100
Subject: [PATCH] Introduce support for Infinity (#72)

---
 index.js               | 13 +++++++++++--
 test/unit/serialize.js | 42 ++++++++++++++++++++++++++++++++++--------
 2 files changed, 45 insertions(+), 10 deletions(-)

diff --git a/index.js b/index.js
index 3594167..841bb7e 100644
--- a/index.js
+++ b/index.js
@@ -8,7 +8,7 @@ See the accompanying LICENSE file for terms.
 
 // Generate an internal UID to make the regexp pattern harder to guess.
 var UID                 = Math.floor(Math.random() * 0x10000000000).toString(16);
-var PLACE_HOLDER_REGEXP = new RegExp('"@__(F|R|D|M|S|U)-' + UID + '-(\\d+)__@"', 'g');
+var PLACE_HOLDER_REGEXP = new RegExp('"@__(F|R|D|M|S|U|I)-' + UID + '-(\\d+)__@"', 'g');
 
 var IS_NATIVE_CODE_REGEXP = /\{\s*\[native code\]\s*\}/g;
 var IS_PURE_FUNCTION = /function.*?\(/;
@@ -57,6 +57,7 @@ module.exports = function serialize(obj, options) {
     var maps      = [];
     var sets      = [];
     var undefs    = [];
+    var infinities= [];
 
     // Returns placeholders for functions and regexps (identified by index)
     // which are later replaced by their string representation.
@@ -102,6 +103,10 @@ module.exports = function serialize(obj, options) {
             return '@__U-' + UID + '-' + (undefs.push(origValue) - 1) + '__@';
         }
 
+        if (type === 'number' && !isNaN(origValue) && !isFinite(origValue)) {
+            return '@__I-' + UID + '-' + (infinities.push(origValue) - 1) + '__@';
+        }
+
         return value;
     }
 
@@ -175,7 +180,7 @@ module.exports = function serialize(obj, options) {
         str = str.replace(UNSAFE_CHARS_REGEXP, escapeUnsafeChars);
     }
 
-    if (functions.length === 0 && regexps.length === 0 && dates.length === 0 && maps.length === 0 && sets.length === 0 && undefs.length === 0) {
+    if (functions.length === 0 && regexps.length === 0 && dates.length === 0 && maps.length === 0 && sets.length === 0 && undefs.length === 0 && infinities.length === 0) {
         return str;
     }
 
@@ -203,6 +208,10 @@ module.exports = function serialize(obj, options) {
             return 'undefined'
         }
 
+        if (type === 'I') {
+            return infinities[valueIndex];
+        }
+
         var fn = functions[valueIndex];
 
         return serializeFunc(fn);
diff --git a/test/unit/serialize.js b/test/unit/serialize.js
index 0c0df3d..3944344 100644
--- a/test/unit/serialize.js
+++ b/test/unit/serialize.js
@@ -335,16 +335,18 @@ describe('serialize( obj )', function () {
             var regexKey = /.*/;
             var m = new Map([
                 ['a', 123],
-                [regexKey, 456]
+                [regexKey, 456],
+                [Infinity, 789]
             ]);
-            expect(serialize(m)).to.be.a('string').equal('new Map([["a",123],[new RegExp(".*", ""),456]])');
-            expect(serialize({t: [m]})).to.be.a('string').equal('{"t":[new Map([["a",123],[new RegExp(".*", ""),456]])]}');
+            expect(serialize(m)).to.be.a('string').equal('new Map([["a",123],[new RegExp(".*", ""),456],[Infinity,789]])');
+            expect(serialize({t: [m]})).to.be.a('string').equal('{"t":[new Map([["a",123],[new RegExp(".*", ""),456],[Infinity,789]])]}');
         });
 
         it('should deserialize a map', function () {
             var m = eval(serialize(new Map([
                 ['a', 123],
-                [null, 456]
+                [null, 456],
+                [Infinity, 789]
             ])));
             expect(m).to.be.a('Map');
             expect(m.get(null)).to.equal(456);
@@ -357,23 +359,47 @@ describe('serialize( obj )', function () {
             var m = new Set([
                 'a',
                 123,
-                regex
+                regex,
+                Infinity
             ]);
-            expect(serialize(m)).to.be.a('string').equal('new Set(["a",123,new RegExp(".*", "")])');
-            expect(serialize({t: [m]})).to.be.a('string').equal('{"t":[new Set(["a",123,new RegExp(".*", "")])]}');
+            expect(serialize(m)).to.be.a('string').equal('new Set(["a",123,new RegExp(".*", ""),Infinity])');
+            expect(serialize({t: [m]})).to.be.a('string').equal('{"t":[new Set(["a",123,new RegExp(".*", ""),Infinity])]}');
         });
 
         it('should deserialize a set', function () {
             var m = eval(serialize(new Set([
                 'a',
                 123,
-                null
+                null,
+                Infinity
             ])));
             expect(m).to.be.a('Set');
             expect(m.has(null)).to.equal(true);
         });
     });
 
+    describe('Infinity', function () {
+        it('should serialize Infinity', function () {
+            expect(serialize(Infinity)).to.equal('Infinity');
+            expect(serialize({t: [Infinity]})).to.be.a('string').equal('{"t":[Infinity]}');
+        });
+
+        it('should deserialize Infinity', function () {
+            var d = eval(serialize(Infinity));
+            expect(d).to.equal(Infinity);
+        });
+
+        it('should serialize -Infinity', function () {
+            expect(serialize(-Infinity)).to.equal('-Infinity');
+            expect(serialize({t: [-Infinity]})).to.be.a('string').equal('{"t":[-Infinity]}');
+        });
+
+        it('should deserialize -Infinity', function () {
+            var d = eval(serialize(-Infinity));
+            expect(d).to.equal(-Infinity);
+        });
+    });
+
     describe('XSS', function () {
         it('should encode unsafe HTML chars to Unicode', function () {
             expect(serialize('</script>')).to.equal('"\\u003C\\u002Fscript\\u003E"');