[Bug] Extracting substring to token value doesn't reference tag properly

I’d need to chain certain requests. In the middle of the chain I’d need to parse a substring from a response JSON field and use that value in the next step. I couldn’t find out way to do this. Is it possible somehow?

Example:

Response body

{
  "url": "https://redirect.to?code=abc123"
}

And I’d like to extract the code query param value from the $.url field.

[gschier]

You’ll have to store the response value in a temporary environment variable first.

For example:

{
  "url": "<RESPONSE TAG>",
  "code": "{{ url | replace('https://redirect.to?code=', '') }}"
}

Is this for OAuth 2.0? If so, have you tried using Insomnia’s built-in OAuth 2.0 support?

[develohpanda]

I spent some time investigating this one, and here are my findings. There isn’t an issue with how a variable is resolved for a request, there is a more fundamental issue with resolving variables, because I managed to reproduce this bug within the environment variable editor.

If the piped variable is coming from a block using insomnia-plugin-response, we see this behavior

{
  "url": "{% response 'body', ... %}", // returns https://redirect.to?code=123
  "code": "{{ url | replace('https://redirect.to?code=', '') }}" // returns 123
  "use-code": "{{ code }}" // returns https://redirect.to?code=123
}

And if the piped variable is coming from a regular string, we see this behavior

{
  "url": "https://redirect.to?code=123", // returns https://redirect.to?code=123
  "code": "{{ url | replace('https://redirect.to?code=', '') }}" // returns 123
  "use-code": "{{ code }}" // returns 123
}

It seems there is an issue with nunjucks, when nesting variable <- variable <- block, while variable <- variable <- variable works.

I can see some interesting behavior inside the templating.render, when we call the nunjucks renderString method, but I’m going in circles at this point and need to bounce some ideas I think.

https://github.com/Kong/insomnia/blob/e485d55aea4fd2edf09088feeecb4d19a1c75d7f/packages/insomnia-app/app/templating/index.js#L42-L46