session 6

Author: tebeka

README.md

@@ -286,5 +286,35 @@ Miki Tebeka
 - [Secure Code Slides](_extra/secure-go.pdf)
 - [journal.tar.gz](_extra/journal.tar.gz)
 
+---
+## Session 6: Testing
+
+### Agenda
+
+- Running services
+- Mocking and when to avoid them
+- Reading test data from files
+- Fuzzing
+
+### Code
+
+TBD
+
+### Links
+
+- Linters
+    - [staticcheck](https://staticcheck.dev/)
+    - [golangci-lint](https://golangci-lint.run/)
+    - [x/tools/analysis](https://pkg.go.dev/golang.org/x/tools/go/analysis) - Write your own
+- [Getting Started with Fuzzing](https://go.dev/doc/tutorial/fuzz)
+- [Testcontainers for Go](https://golang.testcontainers.org/)
+
+
+### Data & Other
+
+```
+¯\_(ツ)_/¯
+```
+
 
 ![](https://pixel-73339669570.me-west1.run.app/p/para2/p.png)

unter/.gitignore

@@ -0,0 +1 @@
+cars.db

unter/Makefile

@@ -0,0 +1,8 @@
+tag = cars/httpd
+
+build-docker:
+	docker build -t $(tag) .
+
+
+run-docker:
+	docker run --rm -p 8080:8080 $(tag)

unter/api.go

@@ -0,0 +1,64 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"log/slog"
+	"net/http"
+)
+
+type API struct {
+	log *slog.Logger
+	db  *DB
+}
+
+func (a *API) Health(w http.ResponseWriter, r *http.Request) {
+	// TODO: Health check
+	fmt.Fprintln(w, "OK")
+}
+
+func (a *API) Get(w http.ResponseWriter, r *http.Request) {
+	id := r.PathValue("id")
+	if id == "" {
+		http.Error(w, "missing ID", http.StatusBadRequest)
+		return
+	}
+
+	rd, err := a.db.Get(id)
+	if err != nil {
+		a.log.Error("scan", "error", err)
+		http.Error(w, "can't get rides", http.StatusInternalServerError)
+		return
+	}
+
+	w.Header().Set("content-type", "application/json")
+	if err := json.NewEncoder(w).Encode(rd); err != nil {
+		a.log.Error("encode", "error", err)
+		return
+	}
+}
+
+func (a *API) Add(w http.ResponseWriter, r *http.Request) {
+	var rd Ride
+	if err := json.NewDecoder(r.Body).Decode(&rd); err != nil {
+		a.log.Error("decode", "error", err)
+		http.Error(w, "bad record", http.StatusBadRequest)
+		return
+	}
+
+	if err := rd.Validate(); err != nil {
+		a.log.Error("validate", "error", err)
+		http.Error(w, "bad record", http.StatusBadRequest)
+		return
+	}
+
+	if err := a.db.Insert(rd); err != nil {
+		a.log.Error("insert", "error", err)
+		http.Error(w, "can't insert", http.StatusInternalServerError)
+		return
+	}
+
+	json.NewEncoder(w).Encode(map[string]any{
+		"id": rd.ID,
+	})
+}

unter/auth.go

@@ -0,0 +1,21 @@
+package main
+
+type User struct {
+	Login string
+}
+
+type Auth struct {
+}
+
+func NewAuth() *Auth {
+	a := Auth{}
+	return &a
+}
+
+func (a *Auth) Login(user, passwd string) (User, bool) {
+	if user == "joe" && passwd == "baz00ka" {
+		return User{"joe"}, true
+	}
+
+	return User{}, false
+}

unter/client.go

@@ -0,0 +1,36 @@
+package main
+
+import (
+	"fmt"
+	"net/http"
+	"net/url"
+)
+
+type Client struct {
+	baseURL string
+	c       http.Client
+}
+
+func NewClient(baseURL string) Client {
+	return Client{baseURL: baseURL}
+}
+
+func (c *Client) Health() error {
+	url, err := url.JoinPath(c.baseURL, "/health")
+	if err != nil {
+		return err
+	}
+
+	resp, err := c.c.Get(url)
+	if err != nil {
+		return err
+	}
+
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return fmt.Errorf("%s: bad status - %s", url, resp.Status)
+	}
+
+	return nil
+}

unter/db.go

@@ -0,0 +1,78 @@
+package main
+
+import (
+	"bytes"
+	"encoding/gob"
+	"fmt"
+
+	"go.etcd.io/bbolt"
+)
+
+var (
+	bucketName = []byte("rides")
+)
+
+type DB struct {
+	conn *bbolt.DB
+}
+
+func NewDB(fileName string) (*DB, error) {
+	conn, err := bbolt.Open(fileName, 0666, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	err = conn.Update(func(tx *bbolt.Tx) error {
+		_, err := tx.CreateBucketIfNotExists(bucketName)
+		return err
+	})
+
+	if err != nil {
+		conn.Close()
+		return nil, err
+	}
+
+	db := DB{conn}
+	return &db, nil
+}
+
+func (db *DB) Close() error {
+	return db.conn.Close()
+}
+
+func (db *DB) Insert(r Ride) error {
+	var buf bytes.Buffer
+	if err := gob.NewEncoder(&buf).Encode(r); err != nil {
+		return err
+	}
+
+	err := db.conn.Update(func(tx *bbolt.Tx) error {
+		b := tx.Bucket(bucketName)
+		return b.Put([]byte(r.ID), buf.Bytes())
+	})
+	return err
+}
+
+func (db *DB) Get(id string) (Ride, error) {
+	var r Ride
+
+	err := db.conn.View(func(tx *bbolt.Tx) error {
+		b := tx.Bucket(bucketName)
+		data := b.Get([]byte(id))
+		if data == nil {
+			return fmt.Errorf("%q not found", id)
+		}
+
+		if err := gob.NewDecoder(bytes.NewReader(data)).Decode(&r); err != nil {
+			return err
+		}
+
+		return nil
+	})
+
+	if err != nil {
+		return Ride{}, err
+	}
+
+	return r, nil
+}

unter/go.mod

@@ -0,0 +1,10 @@
+module unter
+
+go 1.25
+
+require go.etcd.io/bbolt v1.4.3
+
+require (
+	github.com/stretchr/testify v1.11.1 // indirect
+	golang.org/x/sys v0.39.0 // indirect
+)

unter/go.sum

@@ -0,0 +1,14 @@
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
+github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
+go.etcd.io/bbolt v1.4.3 h1:dEadXpI6G79deX5prL3QRNP6JB8UxVkqo4UPnHaNXJo=
+go.etcd.io/bbolt v1.4.3/go.mod h1:tKQlpPaYCVFctUIgFKFnAlvbmB3tpy1vkTnDWohtc0E=
+golang.org/x/sync v0.10.0 h1:3NQrjDixjgGwUOCaF8w2+VYHv0Ve/vGYSbdkTa98gmQ=
+golang.org/x/sync v0.10.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
+golang.org/x/sys v0.39.0 h1:CvCKL8MeisomCi6qNZ+wbb0DN9E5AATixKsvNtMoMFk=
+golang.org/x/sys v0.39.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

unter/main.go

@@ -0,0 +1,45 @@
+package main
+
+import (
+	"fmt"
+	"log/slog"
+	"net/http"
+	"os"
+)
+
+func main() {
+	log := slog.Default().With("app", "cars")
+	dbFile := os.Getenv("CARS_DB")
+	if dbFile == "" {
+		dbFile = "cars.db"
+	}
+	addr := os.Getenv("CARS_ADDR")
+	if addr == "" {
+		addr = ":8080"
+	}
+
+	db, err := NewDB(dbFile)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "error: can't create DB (%s)\n", err)
+		os.Exit(1)
+	}
+
+	api := API{
+		log: log,
+		db:  db,
+	}
+	mux := http.NewServeMux()
+	mux.HandleFunc("GET /health", api.Health)
+	mux.HandleFunc("POST /rides", api.Add)
+	mux.HandleFunc("GET /ride/{id}", api.Get)
+
+	srv := http.Server{
+		Addr:    addr,
+		Handler: mux,
+	}
+	log.Info("server starting", "address", srv.Addr)
+	if err := srv.ListenAndServe(); err != nil {
+		log.Error("serve", "error", err)
+		os.Exit(1)
+	}
+}