Added tests and readme

internal/alerts/message_test.go

@@ -0,0 +1,52 @@
+package alerts
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/jasper/quptime/internal/checks"
+	"github.com/jasper/quptime/internal/config"
+)
+
+func TestRenderDownTransition(t *testing.T) {
+	check := &config.Check{Name: "homepage", Target: "https://example.com", Type: config.CheckHTTP}
+	snap := checks.Snapshot{Reports: 3, OKCount: 0, NotOK: 3, Detail: "connection refused"}
+	msg := Render("master-node", check, checks.StateUp, checks.StateDown, snap)
+
+	if !strings.Contains(msg.Subject, "DOWN") {
+		t.Errorf("subject missing DOWN: %q", msg.Subject)
+	}
+	if !strings.Contains(msg.Subject, "homepage") {
+		t.Errorf("subject missing check name: %q", msg.Subject)
+	}
+	if !strings.Contains(msg.Body, "connection refused") {
+		t.Errorf("body missing detail: %q", msg.Body)
+	}
+	if !strings.Contains(msg.Body, "master-node") {
+		t.Errorf("body missing reporter: %q", msg.Body)
+	}
+	if !strings.Contains(msg.Body, "3 (ok=0, fail=3)") {
+		t.Errorf("body missing report count: %q", msg.Body)
+	}
+}
+
+func TestRenderRecoveryTransition(t *testing.T) {
+	check := &config.Check{Name: "api", Target: "https://api/", Type: config.CheckHTTP}
+	snap := checks.Snapshot{Reports: 3, OKCount: 3, NotOK: 0}
+	msg := Render("master", check, checks.StateDown, checks.StateUp, snap)
+	if !strings.Contains(msg.Subject, "RECOVERED") {
+		t.Errorf("subject missing RECOVERED: %q", msg.Subject)
+	}
+}
+
+func TestRenderUpInitialTransition(t *testing.T) {
+	check := &config.Check{Name: "api", Target: "https://api/"}
+	snap := checks.Snapshot{Reports: 1, OKCount: 1}
+	msg := Render("master", check, checks.StateUnknown, checks.StateUp, snap)
+	if !strings.Contains(msg.Subject, "UP") {
+		t.Errorf("subject missing UP: %q", msg.Subject)
+	}
+	if strings.Contains(msg.Subject, "RECOVERED") {
+		t.Error("first-time UP should not be tagged RECOVERED")
+	}
+}