Last night I had the chance to give a short presentation on how we use containers for testing at Synthesio during the Meetup Golang Paris & Modern Devops.

7. func TestShouldUpdateStats(t *testing.T) {
db, mock, err := sqlmock.New()
if err != nil {
t.Fatalf("an error '%s' was not expected when opening a stub database connection", err)
}
defer db.Close()
mock.ExpectBegin()
mock.ExpectExec("UPDATE products").WillReturnResult(sqlmock.NewResult(1, 1))
mock.ExpectExec("INSERT INTO product_viewers").WillReturnResult(sqlmock.NewResult(1, 1))
mock.ExpectCommit()
// now we execute our method
if err = recordStats(db, 2, 3); err != nil {
t.Errorf("error was not expected while updating stats: %s", err)
}
// we make sure that all expectations were met
if err := mock.ExpectationsWereMet(); err != nil {
t.Errorf("there were unfulfilled expectations: %s", err)
}
}

8. $ tree .
.
├── conda.mk
├── docker-compose.yml
├── base.mk
├── golang.mk
├── node.mk
├── php.mk
├── etc
│ ├── elasticsearch
│ │ ├── elasticsearch.yml
│ │ └── jvm.options
│ └── mysql
│ └── my.cnf
└── schemas
├── ...
├── crumble-1.0.0.cql
├── crumble-2.0.0.cql
├── crumble-migration-1.0.0-2.0.0.cql
├── reiatsu-1.0.0.sql
├── reiatsu-1.1.0.sql
├── reiatsu-1.2.0.sql
├── reiatsu-migration-1.0.0-1.1.0.sql
├── reiatsu-migration-1.1.0-1.2.0.sql
└── ...

9. export STO_STDDIRNAME ?= standard
export STO_STDPATH ?= $(realpath $(PWD)/../$(STO_STDDIRNAME))
export STO_STDMAKEFILE ?= $(STO_STDPATH)/golang.mk
export STO_STDCOMPOSEFILE ?= $(STO_STDPATH)/docker-compose.yml
include $(STO_STDMAKEFILE)
$ make help
build build the project
clean remove project's dependencies, cache, binaries and ci artifacts
dist-build dist build the project
down shut down docker composition
help print this message
lint-ci lint project's code for ci
lint lint project's code
prepare-build prepare for build
prepare-ci prepare for ci
pull pull docker composition images
shell run project's shell
test-ci run ci test configuration
test-fast run minimal test configuration
test run complete test configuration
up start up docker composition

10. version: "2.1"
services:
service:
extends:
file: ${STO_STDCOMPOSEFILE}
service: golang-1.9
entrypoint: dockerize -timeout 20s -wait tcp://elasticsearch:9200 -wait tcp://kafka:9092 entrypoint.sh
links:
- elasticsearch
- kafka
elasticsearch:
extends:
file: ${STO_STDCOMPOSEFILE}
service: elasticsearch-2.3
kafka:
extends:
file: ${STO_STDCOMPOSEFILE}
service: kafka-0.10
links:
- zookeeper
zookeeper:
extends:
file: ${STO_STDCOMPOSEFILE}
service: zookeeper-3.4

11. func TestService_poll(t *testing.T) {
var c Case{
Name: "poll new trigger",
Fixture: "poll_new",
Out: Trigger{
ID: 1,
DashboardID: 1,
},
}
redbeard, clean := mysqltest.Spawn(t, zmysql.NewRedbeard, "redbeard:3306",
mysqltest.Fixture{Path: "${STO_STDPATH}/schemas/redbeard-0.2.0.sql"},
mysqltest.Fixture{Path: "testdata/" + c.Fixture + ".sql"},
)
defer clean()
service := NewService(redbeard)
out, err := service.poll()
if (err != nil) != c.Err || err != c.ErrValue {
t.Errorf("unexpected error: got %v", err)
}
if !reflect.DeepEqual(c.Out, out) {
t.Errorf("unexpected output: %s", ztesting.Diff(out, c.Out))
}
}

12. time.Now()
var ReferenceDate = time.Date(2006, 01, 02, 15, 04, 05, 000, time.UTC)
func init() {
monkey.Patch(time.Now, func() time.Time {
return ReferenceDate
})
defer monkey.Unpatch(time.Now)
}
func TestCreate(t *testing.T) {
// …
Create(db, Entity{
ID: 1,
})
var res Entity
db.Get(&res, `SELECT * FROM entities`)
expected := Entity{
ID: 1,
CreatedAt: ReferenceDate,
}
if !reflect.DeepEqual(res, expected) {
t.Errorf("unexpected output: got %v, wanted %v", res, expected)
}
// …
}

13. t.Run(c.name, func(t *testing.T) {
service, clean := NewTestService(t, ...)
defer clean()
out, err := service.generate(c.job)
if (err != nil) != c.err {
t.Fatalf("unexpected error calling generate: got %v", err)
}
if c.err {
return
}
var expected Presentation
golden.ReadJSON(t, c.out, &expected, out)
if !jsonEqual(out, expected) {
t.Errorf("unexpected output: %v", ztesting.Diff(out, expected))
}
})