update readme and add example

* dcca987 add an old example and a basic one

examples/blog/blog.go

@@ -0,0 +1,81 @@
+package main
+
+import (
+	"database/sql"
+	"encoding/json"
+	"net/http"
+)
+
+type api struct {
+	db *sql.DB
+}
+
+type post struct {
+	ID    int
+	Title string
+	Body  string
+}
+
+func (a *api) posts(w http.ResponseWriter, r *http.Request) {
+	rows, err := a.db.Query("SELECT id, title, body FROM posts")
+	if err != nil {
+		a.fail(w, "failed to fetch posts: "+err.Error(), 500)
+		return
+	}
+	defer rows.Close()
+
+	var posts []*post
+	for rows.Next() {
+		p := &post{}
+		if err := rows.Scan(&p.ID, &p.Title, &p.Body); err != nil {
+			a.fail(w, "failed to scan post: "+err.Error(), 500)
+			return
+		}
+		posts = append(posts, p)
+	}
+	if rows.Err() != nil {
+		a.fail(w, "failed to read all posts: "+rows.Err().Error(), 500)
+		return
+	}
+
+	data := struct {
+		Posts []*post
+	}{posts}
+
+	a.ok(w, data)
+}
+
+func main() {
+	// @NOTE: the real connection is not required for tests
+	db, err := sql.Open("mysql", "root@/blog")
+	if err != nil {
+		panic(err)
+	}
+	app := &api{db: db}
+	http.HandleFunc("/posts", app.posts)
+	http.ListenAndServe(":8080", nil)
+}
+
+func (a *api) fail(w http.ResponseWriter, msg string, status int) {
+	w.Header().Set("Content-Type", "application/json")
+
+	data := struct {
+		Error string
+	}{Error: msg}
+
+	resp, _ := json.Marshal(data)
+	w.WriteHeader(status)
+	w.Write(resp)
+}
+
+func (a *api) ok(w http.ResponseWriter, data interface{}) {
+	w.Header().Set("Content-Type", "application/json")
+
+	resp, err := json.Marshal(data)
+	if err != nil {
+		w.WriteHeader(http.StatusInternalServerError)
+		a.fail(w, "oops something evil has happened", 500)
+		return
+	}
+	w.Write(resp)
+}

examples/blog/blog_test.go

@@ -0,0 +1,102 @@
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/DATA-DOG/go-sqlmock"
+)
+
+func (a *api) assertJSON(actual []byte, data interface{}, t *testing.T) {
+	expected, err := json.Marshal(data)
+	if err != nil {
+		t.Fatalf("an error '%s' was not expected when marshaling expected json data", err)
+	}
+
+	if bytes.Compare(expected, actual) != 0 {
+		t.Errorf("the expected json: %s is different from actual %s", expected, actual)
+	}
+}
+
+func TestShouldGetPosts(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()
+
+	// create app with mocked db, request and response to test
+	app := &api{db}
+	req, err := http.NewRequest("GET", "http://localhost/posts", nil)
+	if err != nil {
+		t.Fatalf("an error '%s' was not expected while creating request", err)
+	}
+	w := httptest.NewRecorder()
+
+	// before we actually execute our api function, we need to expect required DB actions
+	rows := sqlmock.NewRows([]string{"id", "title", "body"}).
+		AddRow(1, "post 1", "hello").
+		AddRow(2, "post 2", "world")
+
+	mock.ExpectQuery("^SELECT (.+) FROM posts$").WillReturnRows(rows)
+
+	// now we execute our request
+	app.posts(w, req)
+
+	if w.Code != 200 {
+		t.Fatalf("expected status code to be 200, but got: %d", w.Code)
+	}
+
+	data := struct {
+		Posts []*post
+	}{Posts: []*post{
+		{ID: 1, Title: "post 1", Body: "hello"},
+		{ID: 2, Title: "post 2", Body: "world"},
+	}}
+	app.assertJSON(w.Body.Bytes(), data, t)
+
+	// we make sure that all expectations were met
+	if err := mock.ExpectationsWereMet(); err != nil {
+		t.Errorf("there were unfulfilled expections: %s", err)
+	}
+}
+
+func TestShouldRespondWithErrorOnFailure(t *testing.T) {
+	db, mock, err := sqlmock.New()
+	if err != nil {
+		t.Fatalf("an error '%s' was not expected when opening a stub database connection", err)
+	}
+	defer db.Close()
+
+	// create app with mocked db, request and response to test
+	app := &api{db}
+	req, err := http.NewRequest("GET", "http://localhost/posts", nil)
+	if err != nil {
+		t.Fatalf("an error '%s' was not expected while creating request", err)
+	}
+	w := httptest.NewRecorder()
+
+	// before we actually execute our api function, we need to expect required DB actions
+	mock.ExpectQuery("^SELECT (.+) FROM posts$").WillReturnError(fmt.Errorf("some error"))
+
+	// now we execute our request
+	app.posts(w, req)
+
+	if w.Code != 500 {
+		t.Fatalf("expected status code to be 500, but got: %d", w.Code)
+	}
+
+	data := struct {
+		Error string
+	}{"failed to fetch posts: some error"}
+	app.assertJSON(w.Body.Bytes(), data, t)
+
+	// we make sure that all expectations were met
+	if err := mock.ExpectationsWereMet(); err != nil {
+		t.Errorf("there were unfulfilled expections: %s", err)
+	}
+}