wallet: drop change to fee if amount is less than dust

[Ayush170-Future]

This commit refactors the CoinSelector's select() method to properly handle the calculation of change cost. The change amount is now checked against the cost of change, and if the change is less than the cost, the cost is added to the transaction fee. Additionally, it adds a unit test for the CoinSelector.

Fixes: Issue #26

[emjshrx]

Can we add a test

[Ayush170-Future]

Can we add a test

Yes. I'll fix the lint and add a test in the next force push.

[Ayush170-Future]

Force pushed:

• Hopefully fixes Lint
• Adds a unit test for CoinSelector

[theanmolsharma]

will continue reviewing after you make these changes

[Ayush170-Future]

Force pushed 3c1983e addressing requested changes.

[Ayush170-Future]

Force pushed a9cf64d refactoring the unit test and creating random script for the test transaction output.

[Ayush170-Future]

Force pushed 0e8a816, which changed the random data into constant values.

• I agree with @emjshrx that using random values in unit testing could lead to non-deterministic behavior. Therefore, I ran my code and recorded all the values it produced. I then hard-coded this static data to ensure deterministic results every time.

• I also covered both cases: when the change > dust and when the change <= dust.

• Fixed the nits

[theanmolsharma]

I think this should be the final set of changes required before merging. Nice work and thanks for your contribution.

[Ayush170-Future]

Force pushed ed44b85

• Used it.each()
• Added comments for justifying my calculations
• Replaced less than dust values in the coins with bigger values (more than 1000)
• Rebased on the main

[emjshrx]

ack ed44b85. Lets also wait for @theanmolsharma's approval

[theanmolsharma]

I think we can merge after the comments are addressed.

[Ayush170-Future]

Force pushed 4589fff addressing reviews and rebasing to the main.

[theanmolsharma]

One last nit and then I'll merge. (Ik I've been saying this for the past 3 reviews, but I promise to merge after this)
Awesome work @Ayush170-Future

[Ayush170-Future]

Done!!

Addressed the nit

[theanmolsharma]

ACK 991c16d

[theanmolsharma]

@Ayush170-Future you need to sign the commits so that we can merge. I've enabled branch protection rules that only allow signed commits to be merged in main. It's a good FOSS practice to sign commits.
If you don't have a GPG setup now, I can sign the commits for this PR, but all commits in the future must be signed.

Some helpful links:
https://docs.github.com/en/authentication/managing-commit-signature-verification/signing-commits

[Ayush170-Future]

@Ayush170-Future you need to sign the commits so that we can merge. I've enabled branch protection rules that only allow signed commits to be merged in main. It's a good FOSS practice to sign commits. If you don't have a GPG setup now, I can sign the commits for this PR, but all commits in the future must be signed.

Yes, please sign the commits in this PR, and thanks for letting me know, I'll set it up and sign my commits from now on.