feat: you can now supply your own HTTP agent to a web3.js Connection

[steveluscher]

Problem

There are folks who have good reasons to want to disable or override our default HTTP agent (ie. the thing that implements connection persistence in Node for the RPC). This PR keeps the behaviour of creating the usual default http.Agent, but offers config to disable or override it.

Disable it

new Connection(url, {httpAgent: false});

Supply your own

new Connection(url, {httpAgent: new https.Agent()});

Note, that if you supply your own, it's up to you to dispose of the agent when the connection is no longer needed.

Summary of Changes

• Added an httpAgent config parameter to Connection
• Auto-disable creating the default agent when process.env.NODE_ENV is test.

Fixes #25069.

[codecov]

Codecov Report

Merging #29125 (05f5f5f) into master (4267a15) will decrease coverage by 0.4%.
The diff coverage is n/a.

@@            Coverage Diff            @@
##           master   #29125     +/-   ##
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- Coverage    77.1%    76.7%   -0.5%     
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  Files          55       55             
  Lines        2934     3140    +206     
  Branches      408      472     +64     
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+ Hits         2264     2410    +146     
- Misses        529      565     +36     
- Partials      141      165     +24