whether it can be support javascript eval expression

[sixinyiyu]

Discussion

a config.json

[
  {
   "k": "abc",
   "v": "e.head.headers['user-agent'] + e.head.headers['host']"
  }
[

eg:

((
  conf= pipy.solve('config.json'),
) => pipy()

.pipeline()
 .handleMessageStart(
  e => (
    (headers = e.head.headers)  =>(
           conf.forEach(one => e.head.headers[one.k] = evel(one.v))
    )
   )()
 )()

result:

headers:
user-agent: chrome
host: 1.1.1.1
abc: chromd1.1.1.1

[pajama-coder]

This can be done with pipy.solve(). The difference though is pipy.solve() evaluates from a source file while the JavaScript-esque eval() evaluates from a string. That means you can't have JS expressions as strings in JSON like in the example you show above, but instead, you can have JS expressions in your config if it were a config.js rather than a config.json:

[
  {
   k: "abc",
   v: (e) => e.head.headers['user-agent'] + e.head.headers['host'],
  }
]

As such, you can make calls to that function in your pipelines:

((
  conf = pipy.solve('config.js'),
) => pipy()

.pipeline()
 .handleMessageStart(
  e => (
    (headers = e.head.headers)  =>(
           conf.forEach(({ k, v }) => e.head.headers[k] = v(headers))
    )
   )()
 )()

[sixinyiyu]

thanks, I will try.