issue: 1518 - rpc proxy return value for get uncles by block hash/number by index

[claytonneal]

Description

eth_getUncleByBlockNumberAndIndex
eth_getUncleByBlockHashAndIndex

were returning {} instead of null

Fixes #1518

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• [] New feature (non-breaking change which adds functionality)
• [] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

• rpc unit test
• rpc e2e test

Test Configuration:

• Node.js Version:
• Yarn Version:

Checklist:

• My code follows the coding standards of this project
• I have performed a self-review of my code
• I have commented on my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• New and existing integration tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules
• I have not added any vulnerable dependencies to my code

[github-actions]

Test Coverage

Summary

Lines	Statements	Branches	Functions
	98.99% (4345/4389)	97.53% (1387/1422)	98.9% (901/911)

Title	Tests	Skipped	Failures	Errors	Time
core	827	0 💤	0 ❌	0 🔥	2m 21s ⏱️
network	719	0 💤	0 ❌	0 🔥	4m 52s ⏱️
errors	42	0 💤	0 ❌	0 🔥	17.141s ⏱️
logging	3	0 💤	0 ❌	0 🔥	17.891s ⏱️
hardhat-plugin	19	0 💤	0 ❌	0 🔥	59.821s ⏱️
aws-kms-adapter	23	0 💤	0 ❌	0 🔥	1m 11s ⏱️
ethers-adapter	5	0 💤	0 ❌	0 🔥	1m 14s ⏱️
rpc-proxy	37	0 💤	0 ❌	0 🔥	1m 4s ⏱️