Adds golangci-lint

.gitlab-ci.yml

@@ -9,11 +9,12 @@ check-generate:
   script:
     - nix-shell --run "make generate && git diff --quiet"
 
-check-fmt:
+check-lint:
   stage: format
   image: nixos/nix:latest
   script:
     - nix-shell --run "make fmt && git diff --quiet"
+    - nix-shell --run "make lint"
 
 check-gomod:
   stage: format

Makefile

@@ -11,6 +11,9 @@ test-watch:
 fmt:
 	go fmt ./...
 
+lint:
+	golangci-lint run ./...
+
 run:
 	go run ./cmd/birthdaybot -config example-config.yml
 

README.md

@@ -24,6 +24,11 @@ Template Format, and has the following properties available:
 - `.MonthOfBirth`: the month that the person was born, as number.
 - `.DayOfBirth`: the day that the person was born, as number.
 
+There are as well some functions available to be used:
+
+- `getYearsOld`: receives the year that a user was born, and returns
+  how old the user is getting.
+
 ### Pictures
 
 Alongside the notification for each birthday, the bot can send a
@@ -65,6 +70,12 @@ $ make run
 - [X] Reduce logger verbosity (through levels)
 - [X] Add pictures to birthday notifications
 - [X] Create a configurable template to fill with each notification
+- [X] Add some endpoints
+  - [X] Health endpoint
+  - [X] Next birthdays endpoint
+  - [ ] Birthday list endpoint
+- [X] Allow to use a random port in web tests
+- [X] Web server should be optional
 - [ ] Create different message systems to use with the bot
   - [X] Telegram
   - [ ] Email

birthdays.csv

@@ -1,2 +1,3 @@
 John Doe,john@doe.com,12345,17/04/2192
+John Doe The Second,john@doesecond.com,12543,17/04/2192
 Jane Doe,jane@doe.com,54321,10/11/2020

client/client.go

@@ -0,0 +1,91 @@
+package client
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net/http"
+	"net/url"
+	"strings"
+
+	"git.ctrlz.es/mgdelacroix/birthdaybot/model"
+)
+
+var (
+	ErrEmptyURL = errors.New("URL cannot be empty")
+)
+
+type Client struct {
+	url        string
+	httpClient *http.Client
+	headers    map[string]string
+}
+
+func New(opts ...Option) (*Client, error) {
+	client := &Client{
+		httpClient: &http.Client{},
+	}
+
+	for _, opt := range opts {
+		client = opt(client)
+	}
+
+	if client.url == "" {
+		return nil, ErrEmptyURL
+	}
+
+	return client, nil
+}
+
+func (c *Client) Do(ctx context.Context, method, path, data string, headers map[string]string) (*http.Response, error) {
+	url, err := url.JoinPath(c.url, path)
+	if err != nil {
+		return nil, fmt.Errorf("cannot build request url: %w", err)
+	}
+
+	req, err := http.NewRequestWithContext(ctx, method, url, strings.NewReader(data))
+	if err != nil {
+		return nil, fmt.Errorf("cannot create request: %w", err)
+	}
+
+	for k, v := range c.headers {
+		req.Header.Set(k, v)
+	}
+
+	for k, v := range headers {
+		req.Header.Set(k, v)
+	}
+
+	resp, err := c.httpClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("cannot do request: %w", err)
+	}
+
+	return resp, nil
+}
+
+func (c *Client) Health(ctx context.Context) (bool, error) {
+	resp, err := c.Do(ctx, http.MethodGet, "/health", "", nil)
+	if err != nil {
+		return false, err
+	}
+	defer resp.Body.Close()
+
+	return resp.StatusCode == 200, nil
+}
+
+func (c *Client) NextBirthdays(ctx context.Context) ([]*model.Birthday, error) {
+	resp, err := c.Do(ctx, http.MethodGet, "/next_birthdays", "", nil)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	var birthdays []*model.Birthday
+	if err := json.NewDecoder(resp.Body).Decode(&birthdays); err != nil {
+		return nil, fmt.Errorf("cannot decode birthdays: %w", err)
+	}
+
+	return birthdays, nil
+}

client/options.go

@@ -0,0 +1,17 @@
+package client
+
+type Option func(*Client) *Client
+
+func WithURL(url string) Option {
+	return func(client *Client) *Client {
+		client.url = url
+		return client
+	}
+}
+
+func WithHeaders(headers map[string]string) Option {
+	return func(client *Client) *Client {
+		client.headers = headers
+		return client
+	}
+}

cmd/birthdaybot/main.go

@@ -47,8 +47,16 @@ func main() {
 	c := make(chan os.Signal, 1)
 	signal.Notify(c, syscall.SIGINT, syscall.SIGTERM)
 
-	srv.Start()
+	if err := srv.Start(); err != nil {
+		fmt.Fprintf(os.Stderr, "ERROR: cannot start server: %s\n", err)
+		os.Exit(1)
+	}
+
 	s := <-c
 	srv.Logger.Info("received signal, stopping", "signal", s)
-	srv.Stop()
+
+	if err := srv.Stop(); err != nil {
+		fmt.Fprintf(os.Stderr, "ERROR: cannot stop server: %s\n", err)
+		os.Exit(1)
+	}
 }

example-config.yml

@@ -1,4 +1,8 @@
 ---
+web:
+  enabled: true
+  port: 8080
+
 birthdays:
   file: birthdays.csv
   template: ./birthday_message.tmpl

model/birthdays.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"strconv"
 	"strings"
+	"time"
 )
 
 type Birthday struct {
@@ -19,15 +20,8 @@ func (b *Birthday) Filename() string {
 	return fmt.Sprintf("%d_%d_%d_%s.png", b.YearOfBirth, b.MonthOfBirth, b.DayOfBirth, b.Phone)
 }
 
-func (b *Birthday) ToMap() map[string]any {
+func (b *Birthday) Time() time.Time {
-	return map[string]any{
+	return time.Date(b.YearOfBirth, time.Month(b.MonthOfBirth), b.DayOfBirth, 0, 0, 0, 0, time.Now().Location())
-		"Name":         b.Name,
-		"Email":        b.Email,
-		"Phone":        b.Phone,
-		"YearOfBirth":  b.YearOfBirth,
-		"MonthOfBirth": b.MonthOfBirth,
-		"DayOfBirth":   b.DayOfBirth,
-	}
 }
 
 func NewBirthdayFromRecord(record []string) (*Birthday, error) {
@@ -108,3 +102,36 @@ func FilterByDate(birthdays []*Birthday, day, month, year int) []*Birthday {
 	}
 	return filteredBirthdays
 }
+
+func NextBirthdayDate(birthdays []*Birthday, now time.Time) (int, int, int) {
+	nowRounded := now.Round(24 * time.Hour)
+
+	var nextBirthday *Birthday
+	for _, birthday := range birthdays {
+		if nextBirthday == nil {
+			nextBirthday = birthday
+			continue
+		}
+
+		birthdayTime := birthday.Time()
+		nextBirthdayTime := nextBirthday.Time()
+
+		if nextBirthdayTime.Before(nowRounded) && birthdayTime.After(nowRounded) {
+			nextBirthday = birthday
+			continue
+		}
+
+		if birthdayTime.Before(nextBirthdayTime) {
+			if birthdayTime.After(nowRounded) || nextBirthdayTime.Before(nowRounded) {
+				nextBirthday = birthday
+			}
+		}
+	}
+
+	return nextBirthday.DayOfBirth, nextBirthday.MonthOfBirth, nextBirthday.YearOfBirth
+}
+
+func NextBirthdays(birthdays []*Birthday, now time.Time) []*Birthday {
+	day, month, year := NextBirthdayDate(birthdays, now)
+	return FilterByDate(birthdays, day, month, year)
+}

model/birthdays_test.go

@@ -2,6 +2,7 @@ package model
 
 import (
 	"testing"
+	"time"
 
 	"github.com/stretchr/testify/require"
 )
@@ -55,3 +56,68 @@ func TestFilename(t *testing.T) {
 
 	require.Equal(t, "2022_4_6_123456789.png", birthday.Filename())
 }
+
+func TestNextBirthdayDate(t *testing.T) {
+	firstBirthday := &Birthday{
+		YearOfBirth:  1900,
+		MonthOfBirth: 2,
+		DayOfBirth:   1,
+	}
+
+	secondBirthday := &Birthday{
+		YearOfBirth:  1900,
+		MonthOfBirth: 8,
+		DayOfBirth:   1,
+	}
+
+	birthdays := []*Birthday{firstBirthday, secondBirthday}
+	birthdaysReversed := []*Birthday{secondBirthday, firstBirthday}
+
+	testCases := []struct {
+		Name          string
+		Now           time.Time
+		Birthdays     []*Birthday
+		ExpectedDay   int
+		ExpectedMonth int
+		ExpectedYear  int
+	}{
+		{
+			Name:          "should find first birthday",
+			Now:           time.Date(1900, time.Month(1), 1, 0, 0, 0, 0, time.Now().Location()),
+			ExpectedDay:   1,
+			ExpectedMonth: 2,
+			ExpectedYear:  1900,
+		},
+		{
+			Name:          "should find second birthday",
+			Now:           time.Date(1900, time.Month(4), 1, 0, 0, 0, 0, time.Now().Location()),
+			ExpectedDay:   1,
+			ExpectedMonth: 8,
+			ExpectedYear:  1900,
+		},
+		{
+			Name:          "should find first birthday for next year",
+			Now:           time.Date(1900, time.Month(10), 1, 0, 0, 0, 0, time.Now().Location()),
+			ExpectedDay:   1,
+			ExpectedMonth: 2,
+			ExpectedYear:  1900,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.Name, func(t *testing.T) {
+			t.Run("with birthdays sorted", func(t *testing.T) {
+				day, month, year := NextBirthdayDate(birthdays, tc.Now)
+				require.Equal(t, tc.ExpectedDay, day)
+				require.Equal(t, tc.ExpectedMonth, month)
+				require.Equal(t, tc.ExpectedYear, year)
+			})
+			t.Run("with birthdays reversed", func(t *testing.T) {
+				day, month, year := NextBirthdayDate(birthdaysReversed, tc.Now)
+				require.Equal(t, tc.ExpectedDay, day)
+				require.Equal(t, tc.ExpectedMonth, month)
+				require.Equal(t, tc.ExpectedYear, year)
+			})
+		})
+	}
+}

model/config.go

@@ -3,7 +3,7 @@ package model
 import (
 	"errors"
 	"fmt"
-	"io/ioutil"
+	"os"
 	"strings"
 
 	"gopkg.in/yaml.v3"
@@ -19,6 +19,7 @@ var (
 type Config struct {
 	Birthdays             *BirthdaysConfig             `yaml:"birthdays"`
 	Logger                *LoggerConfig                `yaml:"logger"`
+	Web                   *WebConfig                   `yaml:"web"`
 	TelegramNotifications *TelegramNotificationsConfig `yaml:"telegram_notifications"`
 }
 
@@ -31,6 +32,10 @@ func (c *Config) IsValid() error {
 		return fmt.Errorf("invalid logger config: %w", err)
 	}
 
+	if err := c.Web.IsValid(); err != nil {
+		return fmt.Errorf("invalid web config: %w", err)
+	}
+
 	if c.TelegramNotifications != nil {
 		if err := c.TelegramNotifications.IsValid(); err != nil {
 			return fmt.Errorf("invalid telegram notifications config: %w", err)
@@ -53,6 +58,12 @@ func (c *Config) SetDefaults() {
 
 	c.Logger.SetDefaults()
 
+	if c.Web == nil {
+		c.Web = &WebConfig{}
+	}
+
+	c.Web.SetDefaults()
+
 	if c.TelegramNotifications != nil {
 		c.TelegramNotifications.SetDefaults()
 	}
@@ -99,6 +110,17 @@ func (lc *LoggerConfig) IsValid() error {
 	return nil
 }
 
+type WebConfig struct {
+	Enabled bool `yaml:"enabled"`
+	Port    int  `yaml:"port"`
+}
+
+func (wc *WebConfig) SetDefaults() {}
+
+func (wc *WebConfig) IsValid() error {
+	return nil
+}
+
 type TelegramNotificationsConfig struct {
 	BotToken  string `yaml:"bot_token"`
 	ChannelID string `yaml:"channel_id"`
@@ -119,7 +141,7 @@ func (tnc *TelegramNotificationsConfig) IsValid() error {
 }
 
 func ReadConfig(path string) (*Config, error) {
-	fileBytes, err := ioutil.ReadFile(path)
+	fileBytes, err := os.ReadFile(path)
 	if err != nil {
 		return nil, err
 	}

model/config_test.go

@@ -2,7 +2,6 @@ package model
 
 import (
 	"io"
-	"io/ioutil"
 	"os"
 	"testing"
 
@@ -11,7 +10,7 @@ import (
 
 func TestReadConfig(t *testing.T) {
 	t.Run("should correctly read a configuration file", func(t *testing.T) {
-		f, err := ioutil.TempFile("", "birthdaybot-")
+		f, err := os.CreateTemp("", "birthdaybot-")
 		require.NoError(t, err)
 		defer os.Remove(f.Name())
 
@@ -25,7 +24,7 @@ func TestReadConfig(t *testing.T) {
 	})
 
 	t.Run("should fail if the file doesn't exist", func(t *testing.T) {
-		f, err := ioutil.TempFile("", "birthdaybot-")
+		f, err := os.CreateTemp("", "birthdaybot-")
 		require.NoError(t, err)
 		f.Close()
 		os.Remove(f.Name())

notification/service_telegram.go

@@ -43,7 +43,7 @@ func (tns *TelegramNotificationService) Notify(birthday *model.Birthday, templat
 	var msgText string
 	if template != nil {
 		var stringBuffer bytes.Buffer
-		if err := template.Execute(&stringBuffer, birthday.ToMap()); err != nil {
+		if err := template.Execute(&stringBuffer, birthday); err != nil {
 			return fmt.Errorf("cannot execute template for birthday: %w", err)
 		}
 

parser/csv_parser_test.go

@@ -2,7 +2,7 @@ package parser
 
 import (
 	"io"
-	"io/ioutil"
+	"os"
 	"testing"
 
 	"github.com/stretchr/testify/require"
@@ -10,7 +10,7 @@ import (
 
 func TestParseCsv(t *testing.T) {
 	t.Run("should correctly parse a valid CSV file", func(t *testing.T) {
-		f, err := ioutil.TempFile("", "birthdaybot-")
+		f, err := os.CreateTemp("", "birthdaybot-")
 		require.NoError(t, err)
 
 		_, werr := io.WriteString(f, "John Doe , john@doe.com, 1234, 17/04/2192\nJane Doe,jane@doe.com,4321,15/01/2020\n")

sample.tmpl

@@ -1 +1 @@
-¡Mañana es el cumpleaños de {{.Name}}! Puedes felicitarle o bien escribiendo a {{.Email}} o bien llamando al número {{.Phone}}
+¡Mañana es el cumpleaños de {{.Name}}! Cumple {{getYearsOld .YearOfBirth}} años, puedes felicitarle o bien escribiendo a {{.Email}} o bien llamando al número {{.Phone}}

server/helpers_test.go

@@ -1,10 +1,11 @@
 package server
 
 import (
-	"io/ioutil"
+	"fmt"
 	"os"
 	"testing"
 
+	"git.ctrlz.es/mgdelacroix/birthdaybot/client"
 	"git.ctrlz.es/mgdelacroix/birthdaybot/model"
 	"git.ctrlz.es/mgdelacroix/birthdaybot/notification"
 	notification_mocks "git.ctrlz.es/mgdelacroix/birthdaybot/notification/mocks"
@@ -20,18 +21,22 @@ type TestHelper struct {
 	mockNotificationService *notification_mocks.MockNotificationService
 	mockWorker              *server_mocks.MockWorker
 	srv                     *Server
+	client                  *client.Client
 }
 
 func testConfig(t *testing.T) *model.Config {
-	f, err := ioutil.TempFile("", "birthdaybot-")
+	f, err := os.CreateTemp("", "birthdaybot-")
 	require.NoError(t, err)
 	require.NoError(t, f.Close())
 	require.NoError(t, os.Remove(f.Name()))
 
-	return &model.Config{Birthdays: &model.BirthdaysConfig{File: f.Name()}}
+	return &model.Config{
+		Web:       &model.WebConfig{Enabled: true, Port: 0},
+		Birthdays: &model.BirthdaysConfig{File: f.Name()},
+	}
 }
 
-func SetupTestHelper(t *testing.T) *TestHelper {
+func SetupTestHelper(t *testing.T, opts ...Option) *TestHelper {
 	th := &TestHelper{t: t}
 	th.ctrl = gomock.NewController(t)
 
@@ -54,22 +59,28 @@ func SetupTestHelper(t *testing.T) *TestHelper {
 		},
 	}
 
-	var err error
+	serverOpts := append([]Option{
-	th.srv, err = New(
 		WithConfig(testConfig(t)),
 		WithLogger(log.New(os.Stderr)),
 		WithBirthdays(birthdays),
 		WithNotificationServices(notificationServices),
 		WithWorkers(workers),
-	)
+	}, opts...)
+
+	var err error
+	th.srv, err = New(serverOpts...)
 	require.NoError(t, err)
 
-	th.srv.Start()
+	require.NoError(t, th.srv.Start())
+
+	client, err := client.New(client.WithURL(fmt.Sprintf("http://127.0.0.1:%d", th.srv.WebServer.Port())))
+	require.NoError(t, err)
+	th.client = client
 
 	return th
 }
 
 func (th *TestHelper) TearDown() {
-	th.srv.Stop()
+	require.NoError(th.t, th.srv.Stop())
 	th.ctrl.Finish()
 }

server/server.go

@@ -3,7 +3,9 @@ package server
 import (
 	"errors"
 	"fmt"
+	"path"
 	"text/template"
+	"time"
 
 	"git.ctrlz.es/mgdelacroix/birthdaybot/model"
 	"git.ctrlz.es/mgdelacroix/birthdaybot/notification"
@@ -20,6 +22,7 @@ var (
 type Server struct {
 	Logger               *log.Logger
 	Config               *model.Config
+	WebServer            *WebServer
 	workers              []Worker
 	birthdays            []*model.Birthday
 	notificationServices []notification.NotificationService
@@ -89,30 +92,70 @@ func New(options ...Option) (*Server, error) {
 	if srv.Config.Birthdays.Template != "" {
 		srv.Logger.Debug("parsing birthday template", "file", srv.Config.Birthdays.Template)
 
+		funcs := template.FuncMap{
+			"getYearsOld": func(yearOfBirth int) int {
+				return time.Now().Year() - yearOfBirth
+			},
+		}
+
 		var err error
-		srv.tmpl, err = template.ParseFiles(srv.Config.Birthdays.Template)
+		srv.tmpl, err = template.
+			New(path.Base(srv.Config.Birthdays.Template)).
+			Funcs(funcs).
+			ParseFiles(srv.Config.Birthdays.Template)
 		if err != nil {
 			return nil, fmt.Errorf("cannot parse template file %q: %w", srv.Config.Birthdays.Template, err)
 		}
 	}
 
+	if srv.WebServer == nil && srv.Config.Web.Enabled {
+		srv.Logger.Debug("creating web server")
+
+		ws, err := NewWebServer(srv)
+		if err != nil {
+			return nil, fmt.Errorf("cannot create web server: %w", err)
+		}
+
+		srv.WebServer = ws
+	}
+
 	return srv, nil
 }
 
-func (s *Server) Start() {
+func (s *Server) Start() error {
 	s.Logger.Info("starting server")
+
+	if s.WebServer != nil {
+		if err := s.WebServer.Start(); err != nil {
+			return fmt.Errorf("cannot start web server: %w", err)
+		}
+	}
+
 	for _, worker := range s.workers {
 		worker.Start()
 	}
+
 	s.Logger.Debug("server started", "workers", len(s.workers))
+
+	return nil
 }
 
-func (s *Server) Stop() {
+func (s *Server) Stop() error {
 	s.Logger.Info("stopping server")
+
+	if s.WebServer != nil {
+		if err := s.WebServer.Stop(); err != nil {
+			return fmt.Errorf("cannot stop web server: %w", err)
+		}
+	}
+
 	for _, worker := range s.workers {
 		worker.Stop()
 	}
+
 	s.Logger.Debug("server stopped", "workers", len(s.workers))
+
+	return nil
 }
 
 func (s *Server) Notify(birthday *model.Birthday) error {
@@ -133,3 +176,7 @@ func (s *Server) Notify(birthday *model.Birthday) error {
 func (s *Server) Birthdays() []*model.Birthday {
 	return s.birthdays
 }
+
+func (s *Server) NextBirthdays() []*model.Birthday {
+	return model.NextBirthdays(s.birthdays, time.Now())
+}

server/server_test.go

@@ -1,15 +1,21 @@
 package server
 
 import (
+	"bytes"
 	"errors"
+	"fmt"
+	"os"
 	"testing"
+	"time"
 
+	"git.ctrlz.es/mgdelacroix/birthdaybot/model"
 	"github.com/stretchr/testify/require"
 )
 
 func TestNotify(t *testing.T) {
 	th := SetupTestHelper(t)
 	defer th.TearDown()
+
 	t.Run("should correctly use the notification services to notify", func(t *testing.T) {
 		birthday := th.srv.birthdays[0]
 		th.mockNotificationService.
@@ -35,3 +41,53 @@ func TestNotify(t *testing.T) {
 		require.ErrorIs(t, err, mockErr)
 	})
 }
+
+func TestTemplate(t *testing.T) {
+	t.Run("template should work with birthday data", func(t *testing.T) {
+		// create a template file and populate it
+		f, err := os.CreateTemp("", "birthdaybot-config-")
+		require.NoError(t, err)
+		_, werr := fmt.Fprint(f, "My name is {{.Name}}")
+		require.NoError(t, werr)
+		require.NoError(t, f.Close())
+
+		// create a test config and set the template
+		config := testConfig(t)
+		config.Birthdays.Template = f.Name()
+
+		// create the test helper with the custom config
+		th := SetupTestHelper(t, WithConfig(config))
+		defer th.TearDown()
+
+		birthday := &model.Birthday{Name: "Jane Doe"}
+		expectedString := "My name is Jane Doe"
+
+		var stringBuffer bytes.Buffer
+		require.NoError(t, th.srv.tmpl.Execute(&stringBuffer, birthday))
+		require.Equal(t, expectedString, stringBuffer.String())
+	})
+
+	t.Run("template should work with custom functions", func(t *testing.T) {
+		// create a template file and populate it
+		f, err := os.CreateTemp("", "birthdaybot-config-")
+		require.NoError(t, err)
+		_, werr := fmt.Fprint(f, "I'm getting {{getYearsOld .YearOfBirth}} years old")
+		require.NoError(t, werr)
+		require.NoError(t, f.Close())
+
+		// create a test config and set the template
+		config := testConfig(t)
+		config.Birthdays.Template = f.Name()
+
+		// create the test helper with the custom config
+		th := SetupTestHelper(t, WithConfig(config))
+		defer th.TearDown()
+
+		birthday := &model.Birthday{YearOfBirth: 1980}
+		expectedString := fmt.Sprintf("I'm getting %d years old", time.Now().Year()-birthday.YearOfBirth)
+
+		var stringBuffer bytes.Buffer
+		require.NoError(t, th.srv.tmpl.Execute(&stringBuffer, birthday))
+		require.Equal(t, expectedString, stringBuffer.String())
+	})
+}

server/web.go

@@ -0,0 +1,88 @@
+package server
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net"
+	"net/http"
+
+	"github.com/charmbracelet/log"
+)
+
+type WebServer struct {
+	server     *Server
+	listener   net.Listener
+	logger     *log.Logger
+	httpServer *http.Server
+}
+
+func NewWebServer(server *Server) (*WebServer, error) {
+	listener, err := net.Listen("tcp", fmt.Sprintf(":%d", server.Config.Web.Port))
+	if err != nil {
+		return nil, fmt.Errorf("cannot create listener: %w", err)
+	}
+
+	ws := &WebServer{
+		server:   server,
+		listener: listener,
+		logger:   server.Logger,
+	}
+
+	mux := http.NewServeMux()
+	mux.HandleFunc("/health", ws.healthHandler)
+	mux.HandleFunc("/next_birthdays", ws.nextBirthdayHandler)
+
+	ws.httpServer = &http.Server{Handler: mux}
+
+	return ws, nil
+}
+
+func (ws *WebServer) Start() error {
+	ws.logger.Debug("starting web server")
+
+	go func() {
+		if err := ws.httpServer.Serve(ws.listener); err != nil && !errors.Is(err, http.ErrServerClosed) {
+			ws.logger.Fatal("cannot start web server", "error", err)
+		}
+	}()
+
+	return nil
+}
+
+func (ws *WebServer) Stop() error {
+	ws.logger.Debug("stopping web server")
+
+	if err := ws.httpServer.Close(); err != nil {
+		return fmt.Errorf("cannot stop web server: %w", err)
+	}
+
+	return nil
+}
+
+func (ws *WebServer) Port() int {
+	return ws.listener.Addr().(*net.TCPAddr).Port
+}
+
+func (ws *WebServer) healthHandler(w http.ResponseWriter, r *http.Request) {
+	fmt.Fprint(w, "OK")
+}
+
+func (ws *WebServer) nextBirthdayHandler(w http.ResponseWriter, r *http.Request) {
+	ws.JSON(w, http.StatusOK, ws.server.NextBirthdays())
+}
+
+func (ws *WebServer) JSON(w http.ResponseWriter, statusCode int, data any) {
+	b, err := json.Marshal(data)
+	if err != nil {
+		ws.logger.Error("cannot marshal data", "error", err)
+		http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
+		return
+	}
+
+	w.WriteHeader(statusCode)
+	if _, err := w.Write(b); err != nil {
+		ws.logger.Error("cannot write to response writer", "error", err)
+		http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
+	}
+}

server/web_test.go

@@ -0,0 +1,39 @@
+package server
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestPort(t *testing.T) {
+	th := SetupTestHelper(t)
+	defer th.TearDown()
+
+	port := th.srv.WebServer.Port()
+	require.NotEmpty(t, port)
+}
+
+func TestHealthHandler(t *testing.T) {
+	th := SetupTestHelper(t)
+	defer th.TearDown()
+
+	t.Run("should return ok if the server is up and running", func(t *testing.T) {
+		health, err := th.client.Health(context.Background())
+		require.NoError(t, err)
+		require.True(t, health)
+	})
+}
+
+func TestNextBirthdaysHandler(t *testing.T) {
+	th := SetupTestHelper(t)
+	defer th.TearDown()
+
+	t.Run("should return a list if the server is up and running", func(t *testing.T) {
+		birthdays, err := th.client.NextBirthdays(context.Background())
+		require.NoError(t, err)
+		require.Len(t, birthdays, 1)
+		require.Equal(t, "john@doe.com", birthdays[0].Email)
+	})
+}

server/worker.go

@@ -48,7 +48,9 @@ func (w *SimpleWorker) notifyDay(year, month, day int) {
 
 	for _, b := range birthdays {
 		w.logger.Info("notifying for birthday", "name", b.Name)
-		w.server.Notify(b)
+		if err := w.server.Notify(b); err != nil {
+			w.logger.Error("error notifying for birthday", "name", b.Name, "error", err)
+		}
 	}
 }
 

shell.nix

@@ -15,6 +15,7 @@ pkgs.mkShell {
     gnumake
     modd
     mockgen
+    golangci-lint
   ];
 
   shellHook = ''