Dust amounts cannot be undelegated, range shown from 0.000001 to scientific notation

[D-Nice]

Describe the bug

When you try to unstake from a validator, where there are dust amount of atoms, the transaction dialog fails to proceed, and will either

• encounter an error at the fee calculation, showing NaN, in the case you used "Set Max" and have a ATOM balance greater than 1.
• note a range error, denoting the "valid" range between 0.000001 and your delegated amount in scientific notation, however, no numeral between that range or below the scientific notation works.
• Give a warning that the amount needs to be a numeral, if using "Set Max" when below either 1 atom or 0.000001 (likely the latter).

To Reproduce

Try to unstake from a validator, where you have some dust amount lingering, potentially due to slashing.

Expected behavior

To be able to click "Set Max" on undelegation, and have it undelegate everything from the delegator, so the delegator no longer shows up in the active portfolio list.

Screenshots
If "Set Max" is clicked with dust

If what should be a valid numeral is entered

Desktop (please complete the following information):

• OS: Windows 8
• Browser: Brave + Ledger
• Version: Latest

Relevant issues: #2968 #1442

This PR had seen something similar: #912 (comment) and there was mention of a new issue being created to fix some of the bugs within that PR, but I do not see any mention within that PR of any subsequent issues being filed pertaining to it.

[faboweb]

Awesome find. Thanks we will take care quickly.

[stale]

Is this still relevant? If so, what is blocking it? Is there anything you can do to help move it forward?

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs.

[jbibla]

let's resolve this! it's annoying. @faboweb what is the proposed solution?

[mariopino]

Related problem:

1. Stake 1 STAKE
2. Unstake 0,9999999 STAKE
3. Click NEXT

Unstaking 0,999999 STAKE will calculate the fee correctly.

Seems that fee and total have problems to handle numbers with more than 6 decimals.

[mariopino]

The proposed approach is to filter dust amount delegations in API (don't return them if the amount is smaller than 1e-6 or 0,000001).

Additionally we should validate that entered amounts have 6 max decimal places to be able to calculate transaction fee and total in a safe way.

[mariopino]

Fixed by https://github.com/luniehq/lunie-api/pull/171