From 72da300c1b183ed29bafc41b94e4368283a1aa3e Mon Sep 17 00:00:00 2001
From: Antoine Veldhoven <antoine@invitado.nl>
Date: Wed, 27 Sep 2023 12:44:03 +0200
Subject: [PATCH] Add support for arrow functions to reduce filter.

---
 src/twig.filters.js  | 14 ++++++++++++++
 test/test.filters.js | 12 ++++++++++++
 2 files changed, 26 insertions(+)

diff --git a/src/twig.filters.js b/src/twig.filters.js
index 4fee1026..f1b744ee 100644
--- a/src/twig.filters.js
+++ b/src/twig.filters.js
@@ -865,6 +865,20 @@ module.exports = function (Twig) {
                 });
                 return newValue;
             }
+        },
+        reduce(value, params) {
+            if (is('Array', value)) {
+                const callBackParams = params.params.split(',');
+                return value.reduce((_carry, _v, _k) => {
+                    const data = {};
+                    data[callBackParams[0]] = _carry;
+                    data[callBackParams[1].trim()] = _v;
+                    data[callBackParams[2].trim()] = _k;
+
+                    const template = Twig.exports.twig({data: params.body});
+                    return template.render(data);
+                }, params.args || 0);
+            }
         }
     };
 
diff --git a/test/test.filters.js b/test/test.filters.js
index f2528110..74038841 100644
--- a/test/test.filters.js
+++ b/test/test.filters.js
@@ -883,6 +883,18 @@ describe('Twig.js Filters ->', function () {
         });
     });
 
+    describe('reduce ->', function () {
+        it('should reduce an array (with inital value)', function () {
+            let testTemplate = twig({data: '{{ [1,2,3]|reduce((carry, v, k) => carry + v * k) }}'});
+            testTemplate.render().should.equal('8');
+        });
+        
+        it('should reduce an array)', function () {
+            let testTemplate = twig({data: '{{ [1,2,3]|reduce((carry, v, k) => carry + v * k, 10) }}'});
+            testTemplate.render().should.equal('18');
+        });
+    });
+
     it('should chain', function () {
         const testTemplate = twig({data: '{{ ["a", "b", "c"]|keys|reverse }}'});
         testTemplate.render().should.equal('2,1,0');