function test() public view returns(uint, uint) {
    return (block.timestamp, block.number);
}

it("test", async function () {
    for (let i = 0; i < 100; i++) {
        console.log(await contractInstance.test())
        await sleep(1000)
    }
})

[ { [String: '1524691464'] s: 1, e: 9, c: [ 1524691464 ] },
{ [String: '166'] s: 1, e: 2, c: [ 166 ] } ]
[ { [String: '1524691465'] s: 1, e: 9, c: [ 1524691465 ] },
{ [String: '166'] s: 1, e: 2, c: [ 166 ] } ]
[ { [String: '1524691466'] s: 1, e: 9, c: [ 1524691466 ] },
{ [String: '166'] s: 1, e: 2, c: [ 166 ] } ]
[ { [String: '1524691467'] s: 1, e: 9, c: [ 1524691467 ] },
{ [String: '166'] s: 1, e: 2, c: [ 166 ] } ]
[ { [String: '1524691468'] s: 1, e: 9, c: [ 1524691468 ] },
{ [String: '166'] s: 1, e: 2, c: [ 166 ] } ]
[ { [String: '1524691469'] s: 1, e: 9, c: [ 1524691469 ] },
{ [String: '166'] s: 1, e: 2, c: [ 166 ] } ]

p {0: "1524690793", 1: "157"}
p {0: "1524690793", 1: "157"}
p {0: "1524690793", 1: "157"}
p {0: "1524690793", 1: "157"}
p {0: "1524690793", 1: "157"}
p {0: "1524690793", 1: "157"}
p {0: "1524690793", 1: "157"}