Update healthcheck_test.go

Author: dmarkwat

internal/healthcheck/healthcheck_test.go

@@ -16,6 +16,7 @@ package healthcheck_test
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"io"
 	"net"
@@ -56,9 +57,14 @@ func dialTCP(t *testing.T, addr string) net.Conn {
 	return nil
 }
 
-type fakeDialer struct{}
+type fakeDialer struct {
+	isClosed bool
+}
 
-func (*fakeDialer) Dial(_ context.Context, _ string, _ ...cloudsqlconn.DialOption) (net.Conn, error) {
+func (f *fakeDialer) Dial(_ context.Context, _ string, _ ...cloudsqlconn.DialOption) (net.Conn, error) {
+	if f.isClosed {
+		return nil, errors.New("closed")
+	}
 	conn, _ := net.Pipe()
 	return conn, nil
 }
@@ -67,7 +73,11 @@ func (*fakeDialer) EngineVersion(_ context.Context, _ string) (string, error) {
 	return "POSTGRES_14", nil
 }
 
-func (*fakeDialer) Close() error {
+func (f *fakeDialer) Close() error {
+	if f.isClosed {
+		return errors.New("closed")
+	}
+	f.isClosed = true
 	return nil
 }
 
@@ -222,3 +232,56 @@ func TestHandleReadinessForMaxConns(t *testing.T) {
 		t.Fatalf("want max connections error, got = %v", string(body))
 	}
 }
+func TestHandleReadinessForMinReady(t *testing.T) {
+	p := newTestProxy(t)
+	defer func() {
+		p.Close()
+	}()
+	started := make(chan struct{})
+	check := healthcheck.NewCheck(p, logger)
+	go p.Serve(context.Background(), func() {
+		check.NotifyStarted()
+		close(started)
+	})
+	select {
+	case <-started:
+		// proxy has started
+	case <-time.After(10 * time.Second):
+		t.Fatal("proxy has not started after 10 seconds")
+	}
+
+	conn := dialTCP(t, proxyAddr())
+	defer conn.Close()
+
+	minReadyTest := func(t *testing.T, minReady int, wantCode int) *http.Response {
+		rec := httptest.NewRecorder()
+		check.HandleReadiness(rec, &http.Request{URL: &url.URL{RawQuery: fmt.Sprintf("min-ready=%d", minReady)}})
+		resp := rec.Result()
+		if resp.StatusCode == wantCode {
+			return resp
+		}
+		t.Fatalf("failed to receive status code = %v: %v", wantCode, resp.StatusCode)
+		return nil
+	}
+
+	var resp *http.Response
+
+	resp = minReadyTest(t, 0, http.StatusOK)
+	resp = minReadyTest(t, 1, http.StatusOK)
+	resp = minReadyTest(t, 2, http.StatusBadRequest)
+
+	conn.Close()
+	if err := p.Close(); err != nil {
+		t.Logf("failed to close proxy client: %v", err)
+	}
+
+	resp = minReadyTest(t, 1, http.StatusServiceUnavailable)
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		t.Fatalf("failed to read response body: %v", err)
+	}
+	if !strings.Contains(string(body), "min ready") {
+		t.Fatalf("want max connections error, got = %v", string(body))
+	}
+}