Run results for: Spread it and Assign Again

Run details:

User agent: Mozilla/5.0 (Linux; Android 12; Pixel 4a (5G)) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/102.0.0.0 Mobile Safari/537.36

Browser: Chrome Mobile 102

Operating system: Android

Device Platform: Mobile

Date tested: one year ago

Test name	Executions per second
map	467609.2 Ops/sec
empty assign	346525.9 Ops/sec
data assign	430910.5 Ops/sec
in place mod	1547460.0 Ops/sec

Script Preparation code:

var data = {
  'one': [{
        foo: {
            bar: {
                baz: "hi"
            }
        }
    },
    {
        foo: {
            bar: {
                baz: "hi"
            }
        }
    },
    {
        foo: {
            bar: {
                baz: "hi"
            }
        }
    },
    {
        foo: {
            bar: {
                baz: "hi"
            }
        }
    },
    {
        foo: {
            bar: {
                baz: "hi"
            }
        }
    },
    {
        foo: {
            bar: {
                baz: "hi"
            }
        }
    },
    {
        foo: {
            bar: {
                baz: "hi"
            }
        }
    },
    {
        foo: {
            bar: {
                baz: "hi"
            }
        }
    }
], 'two': [{
        foo: {
            bar: {
                baz: "hi"
            }
        }
    },
    {
        foo: {
            bar: {
                baz: "hi"
            }
        }
    },
    {
        foo: {
            bar: {
                baz: "hi"
            }
        }
    },
    {
        foo: {
            bar: {
                baz: "hi"
            }
        }
    },
    {
        foo: {
            bar: {
                baz: "hi"
            }
        }
    },
    {
        foo: {
          replace: "yes",
            bar: {
                baz: "hi"
            }
        }
    },
    {
        foo: {
            bar: {
                baz: "hi"
            }
        }
    },
    {
        foo: {
            bar: {
                baz: "hi"
            }
        }
    }
]
};

Tests:

map
let f = { ...data, two: data.two.map((item) => { item.foo.replace == "yes" ? { ...item, something: { n: 234, b: 234 } } : item }), };
empty assign
let o = Object.assign({}, data, { two: data.two.map((item) => { item.foo.replace == "yes" ? { ...item, something: { n: 234, b: 234 } } : item }) })
data assign
let o = Object.assign(data, { two: data.two.map((item) => item.foo.replace == "yes" ? { ...item, something: { n: 234, b: 234 } } : item ) });
in place mod
let f = data.two.find((item) => item.foo.replace == "yes"); f.n = 234; f.b = 234; data

Run results for: Spread it and Assign Again

map

empty assign

data assign

in place mod