The semantics of the BigInt type are similar to the Number type.
When operating a BigInt with a number the result is an exception.
➜ babel-learning git:(main) ✗ cat src/exercises/bigint-conversion/input-1-bigint-conversion.js
let a = 2n+3e30;
let b = 4e28 +5n;
let c = 6n + 7n;
console.log(a);
console.log(b);When we try to run the code we get an error:
➜ babel-learning git:(main) node src/exercises/bigint-conversion/input-1-bigint-conversion.js
/Users/casianorodriguezleon/campus-virtual/2324/learning/babel-learning/src/exercises/bigint-conversion/input-1-bigint-conversion.js:1
let a = 2n+3e30;
^
TypeError: Cannot mix BigInt and other types, use explicit conversions
To convert a Number to a BigInt use the BigInt() constructor.
Write a Babel plugin to promote the number to a BigInt when the constant is an integer one.
➜ babel-learning git:(main) ✗ npx babel src/exercises/bigint-conversion/input-1-bigint-conversion.js --plugins=./src/exercises/bigint-conversion/plugin-bigint-conversion.cjs
"use strict";
let a = 2n + 2999999999999999778178897805312n;
let b = 39999999999999998332478947328n + 5n;
let c = 6n + 7n;
console.log(a);
console.log(b);The execution shows a weak point:
➜ babel-learning git:(main) ✗ npx babel src/exercises/bigint-conversion/input-1-bigint-conversion.js --plugins=./src/exercises/bigint-conversion/plugin-bigint-conversion.cjs | node
2999999999999999778178897805314n
39999999999999998332478947333n
We need to convert Numbers like 3e30 to a BigInt without losing precision when the number is a zero padded integer. S.t. like:
> sn = 12.35e40.toString()
'1.235e+41'
> [n, inte, man, exp] = sn.match(/(\d+)(?:[.](\d*))?(?:[eE][+]?(\d+))?/)
> [inte, man, exp]
[ '1', '235', '41' ]
> inte+man+"0".repeat(exp)+"n" # I am assuming exp >= man.length
'123500000000000000000000000000000000000000000n'See the partial solution in /src/exercises/bigint-conversion/plugin-bigint-conversion.cjs.
Improve the solution to handle this cases.