reorganization of _examples and add some new examples such as iris+groupcache+mysql+docker

Former-commit-id: ed635ee95de7160cde11eaabc0c1dcb0e460a620

_examples/url-shortener/main_test.go

@@ -0,0 +1,76 @@
+package main
+
+import (
+	"io/ioutil"
+	"os"
+	"testing"
+	"time"
+
+	"github.com/kataras/iris/v12/httptest"
+)
+
+// TestURLShortener tests the simple tasks of our url shortener application.
+// Note that it's a pure test.
+// The rest possible checks is up to you, take it as as an exercise!
+func TestURLShortener(t *testing.T) {
+	// temp db file
+	f, err := ioutil.TempFile("", "shortener")
+	if err != nil {
+		t.Fatalf("creating temp file for database failed: %v", err)
+	}
+
+	db := NewDB(f.Name())
+	app := newApp(db)
+
+	e := httptest.New(t, app)
+	originalURL := "https://google.com"
+
+	// save
+	e.POST("/shorten").
+		WithFormField("url", originalURL).Expect().
+		Status(httptest.StatusOK).Body().Contains("<pre><a target='_new' href=")
+
+	keys := db.GetByValue(originalURL)
+	if got := len(keys); got != 1 {
+		t.Fatalf("expected to have 1 key but saved %d short urls", got)
+	}
+
+	// get
+	e.GET("/u/" + keys[0]).Expect().
+		Status(httptest.StatusTemporaryRedirect).Header("Location").Equal(originalURL)
+
+	// save the same again, it should add a new key
+	e.POST("/shorten").
+		WithFormField("url", originalURL).Expect().
+		Status(httptest.StatusOK).Body().Contains("<pre><a target='_new' href=")
+
+	keys2 := db.GetByValue(originalURL)
+	if got := len(keys2); got != 1 {
+		t.Fatalf("expected to have 1 keys even if we save the same original url but saved %d short urls", got)
+	} // the key is the same, so only the first one matters.
+
+	if keys[0] != keys2[0] {
+		t.Fatalf("expected keys to be equal if the original url is the same, but got %s = %s ", keys[0], keys2[0])
+	}
+
+	// clear db
+	e.POST("/clear_cache").Expect().Status(httptest.StatusOK)
+	if got := db.Len(); got != 0 {
+		t.Fatalf("expected database to have 0 registered objects after /clear_cache but has %d", got)
+	}
+
+	// give it some time to release the db connection
+	db.Close()
+	time.Sleep(1 * time.Second)
+	// close the file
+	if err := f.Close(); err != nil {
+		t.Fatalf("unable to close the file: %s", f.Name())
+	}
+
+	// and remove the file
+	if err := os.Remove(f.Name()); err != nil {
+		t.Fatalf("unable to remove the file from %s", f.Name())
+	}
+
+	time.Sleep(1 * time.Second)
+}