handler

Utilities for testing individual handlers in isolation and setting up full bot instances with minimal boilerplate.

import telega/testing/handler
import telega/testing/factory
import telega/testing/mock

// Test a single handler without a router
pub fn my_handler_test() {
  let #(ctx, calls) = handler.test_handler(
    session: MySession(count: 0),
    update: factory.text_update(text: "hello"),
    handler: fn(ctx, _update) { reply.with_text(ctx, "hi") |> result.map(fn(_) { ctx }) },
  )
  mock.assert_call_count(from: calls, expected: 1)
}

// Test with a full bot (router + actors)
pub fn my_bot_test() {
  handler.with_test_bot(
    router: build_router(),
    session: fn() { MySession(count: 0) },
    handler: fn(bot_subject, calls) {
      let update = factory.command_update("start")
      bot.handle_update(bot_subject:, update:)
      mock.assert_call_count(from: calls, expected: 1)
    },
  )
}

Values

test_handler

</>

pub fn test_handler(
  session session: session,
  update update: update.Update,
  handler handler: fn(bot.Context(session, error), update.Update) -> Result(
    bot.Context(session, error),
    error,
  ),
) -> #(
  Result(bot.Context(session, error), error),
  process.Subject(mock.ApiCall),
)

Runs a handler function in isolation with a mock client. Returns the resulting context and the recorded API calls subject.

Use this to test a single handler without involving the router or actor system.

with_test_bot

</>

pub fn with_test_bot(
  router router: router.Router(session, error),
  session default_session: fn() -> session,
  handler handler: fn(
    process.Subject(bot.BotMessage),
    process.Subject(mock.ApiCall),
  ) -> Nil,
) -> Nil

Starts a full bot with router, registry, and actors using a mock client. Calls handler with the bot subject and API calls subject, then cleans up.

Use this to test end-to-end update handling with minimal boilerplate.

with_test_bot_advanced

</>

pub fn with_test_bot_advanced(
  router_handler router_handler: fn(
    bot.Context(session, error),
    update.Update,
  ) -> Result(bot.Context(session, error), error),
  session_settings session_settings: bot.SessionSettings(
    session,
    error,
  ),
  handler handler: fn(
    process.Subject(bot.BotMessage),
    process.Subject(mock.ApiCall),
  ) -> Nil,
) -> Nil

Lower-level variant with custom router handler and session settings.