Hola amigos! In this part we're going to complete budgets API, also I'm going to tell you in recent days I've come up with a great combination of tools to build REST APIs much more MVC-like than this that I'm going to write about in incoming posts.
I've just finished with just one single acceptance test for budgets API but here I going to declare various test cases should cover almost 100% of budgets API behaviors. So let's get started:
// budgets_test.go
package main
import (
"net/http"
"os"
"testing"
"github.com/azbshiri/common/test"
"github.com/go-pg/pg"
"github.com/go-pg/pg/orm"
"github.com/gorilla/mux"
"github.com/pquerna/ffjson/ffjson"
"github.com/stretchr/testify/assert"
)
var testServer *server
var badServer *server
func TestMain(m *testing.M) {
testServer = newServer(
pg.Connect(&pg.Options{
User: "alireza",
Password: "alireza",
Database: "alireza_test",
}),
mux.NewRouter(),
)
badServer = newServer(
pg.Connect(&pg.Options{
User: "not_found",
Password: "alireza",
Database: "alireza",
}),
mux.NewRouter(),
)
// Here we create a temporary table to store each test case
// data and follow isolation which would be dropped after.
testServer.db.CreateTable(&budget{}, &orm.CreateTableOptions{
Temp: true,
})
os.Exit(m.Run())
}
func TestGetBudgets_EmptyResponse(t *testing.T) {
var body []budget
res, err := test.DoRequest(testServer, "GET", BudgetPath, nil)
ffjson.NewDecoder().DecodeReader(res.Body, &body)
assert.NoError(t, err)
assert.Len(t, body, 0)
assert.Equal(t, res.Code, http.StatusOK)
}
func TestGetBudgets_NormalResponse(t *testing.T) {
var body []budget
budgets, err := CreateBudgetListFactory(testServer.db, 10)
assert.NoError(t, err)
res, err := test.DoRequest(testServer, "GET", BudgetPath, nil)
assert.Equal(t, http.StatusOK, res.Code)
assert.NoError(t, err)
ffjson.NewDecoder().DecodeReader(res.Body, &body)
assert.Len(t, body, 10)
assert.Equal(t, budgets, &body)
}
func TestGetBudgets_DatabaseError(t *testing.T) {
var body Error
res, err := test.DoRequest(badServer, "GET", BudgetPath, nil)
ffjson.NewDecoder().DecodeReader(res.Body, &body)
assert.NoError(t, err)
assert.Equal(t, DatabaseError, &body)
assert.Equal(t, http.StatusInternalServerError, res.Code)
}
I've defined three test cases normal response, empty response and when there's a database error that we've simulated using a non-existing database username to make database unavailable. Also as you noticed there's a DatabaseError
constant which assert to make sure errors are readable. I've created a errors.go
file in which there are a new error type called Error
as below:
package main
import "net/http"
type Error struct {
Message string `json:"message"`
Status int `json:"status"`
}
func Err(message string, status int) *Error {
return &Error{message, status}
}
var DatabaseError = Err("Your request failed due to a database error.", http.StatusInternalServerError)
It carries a message and a corresponding HTTP code to make dealing with errors easier. Now that everything is in a right place we should pass or tests which are failing in the current state.
So first we go by creating an HTTP handler function in budgets.go
file:
// budgets.go
package main
import (
"net/http"
"github.com/azbshiri/common/db"
)
type budget struct {
db.Model
Amount float64 `json:"amount"`
}
func (s *server) getBudgets(w http.ResponseWriter, r *http.Request) {
}
Then registering the HTTP handle in routes.go
:
// routes.go
package main
const BudgetPath = "/api/budgets"
func (s *server) routes() {
s.mux.HandleFunc(BudgetPath, s.getBudgets).Methods("GET")
}
Note: I defined BudgetPath
constant to be able to use budgets API path in various places including tests. Tests are still failing so we should get budgets from the database and return an acceptable response to consumers. Also, I created a CreateBudgetListFactory
factory in factories.go
file to making database population easier.
// factories.go
package main
import (
"math/rand"
"time"
"github.com/go-pg/pg"
)
func CreateBudgetListFactory(db *pg.DB, length int) (*[]budget, error) {
budgets := make([]budget, length)
for _, budget := range budgets {
budget.Amount = rand.Float64()
budget.CreatedAt = time.Now()
}
err := db.Insert(&budgets)
if err != nil {
return nil, err
}
return &budgets, nil
}
// budgets.go
package main
import (
"encoding/json"
"net/http"
"github.com/azbshiri/common/db"
"github.com/pquerna/ffjson/ffjson"
)
type budget struct {
db.Model
Amount float64 `json:"amount"`
}
func (s *server) getBudgets(w http.ResponseWriter, r *http.Request) {
var budgets []*budget
err := s.db.Model(&budgets).Select()
if err != nil {
w.WriteHeader(http.StatusInternalServerError)
json.NewEncoder(w).Encode(DatabaseError)
return
}
ffjson.NewEncoder(w).Encode(budgets)
}
Now we're green:
=== RUN TestGetBudgets_EmptyResponse
-------- PASS: TestGetBudgets_EmptyResponse (0.00s)
=== RUN TestGetBudgets_NormalResponse
-------- PASS: TestGetBudgets_NormalResponse (0.00s)
=== RUN TestGetBudgets_DatabaseError
-------- PASS: TestGetBudgets_DatabaseError (0.00s)
PASS
ok github.com/azbshiri/budget-api 0.040s
Okay, now we repeating the same steps for creating a new budget API:
// budgets_test.go
package main
import (
"bytes"
"net/http"
"os"
"testing"
"github.com/azbshiri/common/test"
"github.com/go-pg/pg"
"github.com/go-pg/pg/orm"
"github.com/gorilla/mux"
"github.com/pquerna/ffjson/ffjson"
"github.com/stretchr/testify/assert"
)
var testServer *server
var badServer *server
func TestMain(m *testing.M) {
testServer = newServer(
pg.Connect(&pg.Options{
User: "alireza",
Password: "alireza",
Database: "alireza_test",
}),
mux.NewRouter(),
)
badServer = newServer(
pg.Connect(&pg.Options{
User: "not_found",
Password: "alireza",
Database: "alireza",
}),
mux.NewRouter(),
)
testServer.db.CreateTable(&budget{}, &orm.CreateTableOptions{
Temp: true,
})
os.Exit(m.Run())
}
func TestGetBudgets_EmptyResponse(t *testing.T) {
var body []budget
res, err := test.DoRequest(testServer, "GET", BudgetPath, nil)
ffjson.NewDecoder().DecodeReader(res.Body, &body)
assert.NoError(t, err)
assert.Len(t, body, 0)
assert.Equal(t, res.Code, http.StatusOK)
}
func TestGetBudgets_NormalResponse(t *testing.T) {
var body []budget
budgets, err := CreateBudgetListFactory(testServer.db, 10)
assert.NoError(t, err)
res, err := test.DoRequest(testServer, "GET", BudgetPath, nil)
assert.Equal(t, http.StatusOK, res.Code)
assert.NoError(t, err)
ffjson.NewDecoder().DecodeReader(res.Body, &body)
assert.Len(t, body, 10)
assert.Equal(t, budgets, &body)
}
func TestGetBudgets_DatabaseError(t *testing.T) {
var body Error
res, err := test.DoRequest(badServer, "GET", BudgetPath, nil)
ffjson.NewDecoder().DecodeReader(res.Body, &body)
assert.NoError(t, err)
assert.Equal(t, DatabaseError, &body)
assert.Equal(t, http.StatusInternalServerError, res.Code)
}
func TestCreateBudget(t *testing.T) {
var body budget
byt, err := ffjson.Marshal(&budget{Amount: 1000.4})
rdr := bytes.NewReader(byt)
res, err := test.DoRequest(testServer, "POST", BudgetPath, rdr)
ffjson.NewDecoder().DecodeReader(res.Body, &body)
assert.NoError(t, err)
assert.Equal(t, 1000.4, body.Amount)
assert.Equal(t, http.StatusOK, res.Code)
}
func TestCreateBudget_BadParamError(t *testing.T) {
var body Error
res, err := test.DoRequest(testServer, "POST", BudgetPath,
bytes.NewReader([]byte{}))
ffjson.NewDecoder().DecodeReader(res.Body, &body)
assert.NoError(t, err)
assert.Equal(t, BadParamError, &body)
assert.Equal(t, http.StatusBadRequest, res.Code)
}
func TestCreateBudget_DatabaseError(t *testing.T) {
var body Error
byt, err := ffjson.Marshal(&budget{Amount: 1000.4})
rdr := bytes.NewReader(byt)
res, err := test.DoRequest(badServer, "POST", BudgetPath, rdr)
ffjson.NewDecoder().DecodeReader(res.Body, &body)
assert.NoError(t, err)
assert.Equal(t, DatabaseError, &body)
assert.Equal(t, http.StatusInternalServerError, res.Code)
}
Creating a new HTTP handle function for new API:
// budgets.go
package main
import (
"encoding/json"
"net/http"
"github.com/azbshiri/common/db"
"github.com/pquerna/ffjson/ffjson"
)
type budget struct {
db.Model
Amount float64 `json:"amount"`
}
func (s *server) getBudgets(w http.ResponseWriter, r *http.Request) {
var budgets []*budget
err := s.db.Model(&budgets).Select()
if err != nil {
w.WriteHeader(http.StatusInternalServerError)
json.NewEncoder(w).Encode(DatabaseError)
return
}
ffjson.NewEncoder(w).Encode(budgets)
}
func (s *server) createBudget(w http.ResponseWriter, r *http.Request) {
var param struct {
Amount float64 `json:"amount"`
}
err := ffjson.NewDecoder().DecodeReader(r.Body, ¶m)
if err != nil {
w.WriteHeader(http.StatusBadRequest)
json.NewEncoder(w).Encode(BadParamError)
return
}
budget := budget{Amount: param.Amount}
err = s.db.Insert(&budget)
if err != nil {
w.WriteHeader(http.StatusInternalServerError)
json.NewEncoder(w).Encode(DatabaseError)
return
}
ffjson.NewEncoder(w).Encode(budget)
}
Note: I used DTO concept to decode parameters that sent to budget creation API, which is a great way to do so.
And we're done:
=== RUN TestGetBudgets_EmptyResponse
-------- PASS: TestGetBudgets_EmptyResponse (0.01s)
=== RUN TestGetBudgets_NormalResponse
-------- PASS: TestGetBudgets_NormalResponse (0.00s)
=== RUN TestGetBudgets_DatabaseError
-------- PASS: TestGetBudgets_DatabaseError (0.00s)
=== RUN TestCreateBudget
-------- PASS: TestCreateBudget (0.00s)
=== RUN TestCreateBudget_BadParamError
-------- PASS: TestCreateBudget_BadParamError (0.00s)
=== RUN TestCreateBudget_DatabaseError
-------- PASS: TestCreateBudget_DatabaseError (0.00s)
PASS
ok github.com/azbshiri/budget-api (cached)
Please add your comments down below and if you found this informative don't forget to drop a heart for me :D
Top comments (4)
Hi Alireza nice tutorial.I like how you have structured the api right from the server struct.Do you have a github repo for this?
Good to hear. Actually I've moved to this structure which is more mature and you can find the codebase here
github.com/azbshiri/hex-rest-api
Nice work ,Will check it out.
Very nice articles!!!
Easy to understand and well explained!
Thanks:)