{"ScriptPreparationCode":"var collection = Array(10000).fill().map(() =\u003E ({ \r\n section: { id: \u0027id_\u0027 \u002B ~~(Math.random()*10) }, \r\n user: { id: \u0027id_\u0027 \u002B ~~(Math.random()*10) }, \r\n}))","TestCases":[{"Name":"mutate reducer 1","Code":"var result = collection.reduce((acc, { section, user }) =\u003E {\r\n if (!acc[section.id]) {\r\n acc[section.id] = [user.id];\r\n return acc;\r\n }\r\n acc[section.id].push(user.id);\r\n return acc;\r\n }, {});\r\n","IsDeferred":false},{"Name":"mutate reducer 2","Code":"var result = collection.reduce((acc, { section, user }) =\u003E {\r\n acc[section.id] = acc[section.id] || [];\r\n acc[section.id].push(user.id);\r\n return acc;\r\n }, {});","IsDeferred":false},{"Name":"mutate reducer 3","Code":"var result = collection.reduce((acc, { section, user }) =\u003E {\r\n if (!acc[section.id]) {\r\n acc[section.id] = [];\r\n }\r\n acc[section.id].push(user.id);\r\n return acc;\r\n }, {});","IsDeferred":false},{"Name":"shallow copy reducer","Code":" var result = collection.reduce((acc, { section, user }) =\u003E ({\r\n ...acc,\r\n [section.id]: [...(acc[section.id] || []), user.id]\r\n }), {});","IsDeferred":false}]}