расскажешь потом, как решил?
///roundingOfNumber.ts
export default function roundingOfNumber(
value: number = 0,
precision: number = 8,
shift: number = 0
): number {
if (value < 0.000001) {
return roundingOfNumber(value * 10, precision - 1, shift + 1);
}
const arr = String(value).split('.');
if (arr[1]) {
arr[1] = ('0'.repeat(shift) + arr[1]).slice(0, precision + shift);
}
console.log(`!!!! roundingOfNumber.ts:33 \n arr `, arr, '\n !!!!');
return parseFloat(arr.join('.'));
}
////roundingOfNumber.test.ts
import roundingOfNumber from './roundingOfNumber';
import expect from 'expect.js';
describe('roundingOfNumber', () => {
const testOptions = [
{ input: 1, output: 1 },
{ input: 1.1, output: 1.1 },
{ input: 1.9999999999, output: 1.99999999 },
{ input: 1.9999999999, output: 1.9999, precision: 4 },
{ input: 1, output: 1, precision: 4 },
{ input: 0.00009, output: 0, precision: 4 },
{ input: 0.00009, output: 0, precision: 4 },
{ input: 0.000000999, output: 0, precision: 4 },
{ input: 0.000000999, output: 0.00000099, precision: 8 },
{ input: 0.0000000000999, output: 0, precision: 10 },
{ input: 0.0000000000999, output: 0.00000000009, precision: 11 },
];
testOptions.forEach((item, index) => {
const result = roundingOfNumber(item.input, item.precision);
it(`Option ${index + 1}: ${item.input} => ${item.output} precision=${
item.precision
} result=${result}`, () => {
expect(result).to.be(item.output);
});
});
});