101 lines
3.1 KiB
JavaScript
101 lines
3.1 KiB
JavaScript
// Copyright IBM Corp. 2014,2018. All Rights Reserved.
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// Node module: loopback
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// This file is licensed under the MIT License.
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// License text available at https://opensource.org/licenses/MIT
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'use strict';
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var async = require('async');
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var loopback = require('../');
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var expect = require('./helpers/expect');
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var Checkpoint = loopback.Checkpoint.extend('TestCheckpoint');
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describe('Checkpoint', function() {
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describe('bumpLastSeq() and current()', function() {
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beforeEach(function() {
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var memory = loopback.createDataSource({
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connector: loopback.Memory,
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});
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Checkpoint.attachTo(memory);
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});
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it('returns the highest `seq` value', function(done) {
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async.series([
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Checkpoint.bumpLastSeq.bind(Checkpoint),
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Checkpoint.bumpLastSeq.bind(Checkpoint),
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function(next) {
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Checkpoint.current(function(err, seq) {
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if (err) next(err);
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expect(seq).to.equal(3);
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next();
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});
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},
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], done);
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});
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it('Should be no race condition for current() when calling in parallel', function(done) {
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async.parallel([
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function(next) { Checkpoint.current(next); },
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function(next) { Checkpoint.current(next); },
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], function(err, list) {
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if (err) return done(err);
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Checkpoint.find(function(err, data) {
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if (err) return done(err);
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expect(data).to.have.length(1);
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done();
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});
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});
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});
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it('Should be no race condition for bumpLastSeq() when calling in parallel', function(done) {
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async.parallel([
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function(next) { Checkpoint.bumpLastSeq(next); },
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function(next) { Checkpoint.bumpLastSeq(next); },
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], function(err, list) {
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if (err) return done(err);
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Checkpoint.find(function(err, data) {
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if (err) return done(err);
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// The invariant "we have at most 1 checkpoint instance" is preserved
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// even when multiple calls are made in parallel
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expect(data).to.have.length(1);
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// There is a race condition here, we could end up with both 2 or 3 as the "seq".
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// The current implementation of the memory connector always yields 2 though.
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expect(data[0].seq).to.equal(2);
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// In this particular case, since the new last seq is always 2, both results
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// should be 2.
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expect(list.map(function(it) { return it.seq; }))
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.to.eql([2, 2]);
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done();
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});
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});
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});
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it('Checkpoint.current() for non existing checkpoint should initialize checkpoint',
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function(done) {
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Checkpoint.current(function(err, seq) {
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expect(seq).to.equal(1);
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done(err);
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});
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});
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it('bumpLastSeq() works when singleton instance does not exists yet', function(done) {
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Checkpoint.bumpLastSeq(function(err, cp) {
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// We expect `seq` to be 2 since `checkpoint` does not exist and
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// `bumpLastSeq` for the first time not only initializes it to one,
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// but also increments the initialized value by one.
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expect(cp.seq).to.equal(2);
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done(err);
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});
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});
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});
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});
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