sb.yml

# yaml-language-server: $schema=../../schemas/sb-config.schema.json
# JavaScript body transform.
#
# Runs a JavaScript function against the raw body string. The entrypoint is
# the top-level `function transform(body)`, where `body` is a string. The
# script parses the JSON, mutates it, and returns a new JSON string. A
# `static` action seeds the input so the example runs offline.
#
# Run:
#   make run CONFIG=examples/transform-javascript/sb.yml
#
# Test:
#   curl -s -H 'Host: js.local' http://127.0.0.1:8080/
#
# Expected: title reversed, title_length added, body trimmed to 40 chars,
# transformed_by tag added.

proxy:
  http_bind_port: 8080

origins:
  "js.local":
    action:
      type: static
      status: 200
      content_type: application/json
      json_body:
        id: 1
        title: "javascript runs on the request path"
        body: "this body is longer than forty characters so it will be trimmed by the script"
        userId: 7
    transforms:
      - type: javascript
        script: |
          function transform(body) {
            var data = JSON.parse(body);
            if (typeof data.title === "string") {
              data.title_length = data.title.length;
              data.title_reversed = data.title.split("").reverse().join("");
            }
            if (typeof data.body === "string" && data.body.length > 40) {
              data.body = data.body.slice(0, 40) + "...";
            }
            data.transformed_by = "javascript";
            return JSON.stringify(data);
          }