HTTP headers in results produce invalid JSON

[willgorman]

Version and Runtime

Version: 12.8.1
Commit: 19b7458
Runtime: go1.14 darwin/amd64
Date: 2020-03-18T23:14:26Z

Expected Behaviour

I expected to be able to use jq to process JSON formatted vegeta results:
echo 'GET http://httpbin.org/get' | vegeta attack -rate=1 -duration=1s | vegeta encode" | jq

{
  "attack": "",
  "seq": 0,
  "code": 200,
  "timestamp": "2020-03-23T22:55:59.3708787Z",
  "latency": 293490600,
  "bytes_out": 0,
  "bytes_in": 271,
  "error": "",
  "body": "..."
}

Actual Behaviour

echo "GET http://httpbin.org/get" | vegeta attack -rate=1 -duration=1s | vegeta encode | jq  
parse error: Expected separator between values at line 1, column 655

Steps to Reproduce

1. echo "GET http://httpbin.org/get" | vegeta attack -rate=1 -duration=1s | vegeta encode

This produces output like

{"attack":"","seq":0,"code":200,"timestamp":"2020-03-23T17:58:33.347828102-05:00","latency":291316215,"bytes_out":0,"bytes_in":297,"error":"","body":"...","method":"GET","url":"http://httpbin.org/get","headers":[{"key":"Server","value":"gunicorn/19.9.0"}{"key":"Access-Control-Allow-Origin","value":"*"}{"key":"Access-Control-Allow-Credentials","value":"true"}{"key":"Date","value":"Mon, 23 Mar 2020 22:58:33 GMT"}{"key":"Content-Type","value":"application/json"}{"key":"Content-Length","value":"297"}{"key":"Connection","value":"keep-alive"}]}

The objects in the headers array are missing commas between them.

Additional Context

[tsenart]

@willgorman: Please test the latest release: https://github.com/tsenart/vegeta/releases/tag/v12.8.2

[willgorman]

@tsenart 12.8.2 works as expected, thanks for the quick fix!