continuation-local-storage/test/run-and-return.tap.js

userland implementation of https://github.com/joyent/node/issues/5243

'use strict';

// stdlib
var tap = require('tap');
var test = tap.test;
var EventEmitter = require('events').EventEmitter;

// module under test
var context = require('../context.js');

// multiple contexts in use
var tracer = context.createNamespace('tracer');


test("simple tracer built on contexts", function (t) {
  t.plan(7);

  var harvester = new EventEmitter();

  harvester.on('finished', function (transaction) {
    t.ok(transaction, "transaction should have been passed in");
    t.equal(transaction.status, 'ok', "transaction should have finished OK");
    t.equal(Object.keys(process.namespaces).length, 1, "Should only have one namespace.");
  });

  var returnValue = {};

  var returnedValue = tracer.runAndReturn(function(context) {
    t.ok(tracer.active, "tracer should have an active context");
    tracer.set('transaction', {status : 'ok'});
    t.ok(tracer.get('transaction'), "can retrieve newly-set value");
    t.equal(tracer.get('transaction').status, 'ok', "value should be correct");

    harvester.emit('finished', context.transaction);

    return returnValue;
  });

  t.equal(returnedValue, returnValue, "method should pass through return value of function run in scope");
});