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Using the ctx · 57 / 69

Read configuration with a fallback

YOUR TASK

Make this happen

3 steps

  1. Keep forwarding the key and default to the host. When the host returns false, return your local fallback instead of leaking its error as a setting. Check solution runs both cases. In the platform, configuration belongs to the account or the integration instance, depending on where the script runs.

  2. Read the cases in lesson.test.lua, then choose Check solution to see what needs to change.

  3. Update subject.lua until every test passes. Keep the supplied tests unchanged.

Start with Check solution, then use the failures to guide your edits.

Read the starter and tests

subject.lua

exports.setting = function(key: string, fallback: string)
  local ok, value = ctx.config.get(key, fallback)
  return value
end

lesson.test.lua

local t = require("test")
local subject = require("cococo.subject")

t.it("forwards the key and default", function()
  t.mock.host("ctx.config.get"):returns(true, "production")
  local s = subject.load()
  t.expect(s.setting("environment", "sandbox")):eq("production")
  t.expect(t.mock.spy("ctx.config.get")):called_with("environment", "sandbox")
end)
t.it("uses a local fallback when the host fails", function()
  t.mock.host("ctx.config.get"):returns(false, "unavailable")
  local s = subject.load()
  t.expect(s.setting("environment", "sandbox")):eq("sandbox")
end)