NumericInput up/down keypress/button click breaks on stepsize smaller than 0.001

[cybae0804]

Environment

• Package version(s): @blueprintjs/core: "3.38.1"
• Operating System: Ubuntu 20.04 LTS
• Browser name and version: Chrome 87.0.4280.141

Code Sandbox

https://codesandbox.io/s/blueprint-sandbox-forked-98i26

Steps to reproduce

Provide a stepSize and minorStepSize such as 0.0001, and try to modify the input using the up/down button or the keypress. It will lock up and won't fire onValueChange correctly.

Actual behavior

Freezes

Expected behavior

Increments/Decrements value correctly

Possible solution

Tried to investigate a bit but couldn't figure it out. The count decimals util function seems to be working correctly however.

[tonooo71]

I'm using the v4.0.0-alpha version and I also encountered the same bug.

I think the cause of this bug is num.toLocaleString(locale) in the toLocaleString function of numericInputUtils.ts.
The numeric string obtained by num.toLocaleString(locale) is truncated to the fourth decimal place.
Number.prototype.toLocaleString(): MDN

So, for example, by using num.toLocaleString(locale, { maximumSignificantDigits: 10 }), I think the number up to the tenth decimal place will work on NumericInput.

[SquareByte]

Issue still exists in v5.0.0

[Rafael-Martins]

I'm using the v4.0.0-alpha version and I also encountered the same bug.

I think the cause of this bug is num.toLocaleString(locale) in the toLocaleString function of numericInputUtils.ts. The numeric string obtained by num.toLocaleString(locale) is truncated to the fourth decimal place. Number.prototype.toLocaleString(): MDN

So, for example, by using num.toLocaleString(locale, { maximumSignificantDigits: 10 }), I think the number up to the tenth decimal place will work on NumericInput.

Opened a pr based on this solution, but I'm not assured why this is happening 🤔 I will do more investigation tomorrow, but, the solution is working and I wrote some tests to cover it

[TheRayTracer]

Does this also resolve?: #4045