test: add tests for handler, email, cmd/server, version and enforce 80% coverage

cmd/server/main_test.go

@@ -0,0 +1,118 @@
+//go:build linux || freebsd
+
+package main
+
+import (
+	"io"
+	"log/slog"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+func TestItoa(t *testing.T) {
+	tests := []struct {
+		n    int
+		want string
+	}{
+		{0, "0"},
+		{1, "1"},
+		{9, "9"},
+		{10, "10"},
+		{42, "42"},
+		{100, "100"},
+		{-1, "-1"},
+		{-42, "-42"},
+		{8080, "8080"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.want, func(t *testing.T) {
+			if got := itoa(tt.n); got != tt.want {
+				t.Errorf("itoa(%d) = %q, want %q", tt.n, got, tt.want)
+			}
+		})
+	}
+}
+
+func TestLast(t *testing.T) {
+	tests := []struct {
+		s    string
+		c    byte
+		want int
+	}{
+		{"hello", 'l', 3},
+		{"hello", 'o', 4},
+		{"hello", 'h', 0},
+		{"hello", 'x', -1},
+		{"", 'a', -1},
+		{"aaa", 'a', 2},
+	}
+
+	for _, tt := range tests {
+		if got := last(tt.s, tt.c); got != tt.want {
+			t.Errorf("last(%q, %q) = %d, want %d", tt.s, tt.c, got, tt.want)
+		}
+	}
+}
+
+func TestClientIP(t *testing.T) {
+	tests := []struct {
+		name       string
+		remoteAddr string
+		want       string
+	}{
+		{"ipv4 with port", "192.168.1.1:12345", "192.168.1.1"},
+		{"ipv6 with brackets", "[::1]:12345", "[::1]"},
+		{"ipv4 without port", "192.168.1.1", "192.168.1.1"},
+		{"empty", "", ""},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			req := httptest.NewRequest(http.MethodGet, "/", nil)
+			req.RemoteAddr = tt.remoteAddr
+			if got := clientIP(req); got != tt.want {
+				t.Errorf("clientIP() = %q, want %q", got, tt.want)
+			}
+		})
+	}
+}
+
+func TestStatusRecorder(t *testing.T) {
+	rec := httptest.NewRecorder()
+	sr := &statusRecorder{ResponseWriter: rec, status: http.StatusOK}
+
+	// Default status before WriteHeader.
+	if sr.status != http.StatusOK {
+		t.Errorf("initial status = %d, want %d", sr.status, http.StatusOK)
+	}
+
+	sr.WriteHeader(http.StatusNotFound)
+	if sr.status != http.StatusNotFound {
+		t.Errorf("status after WriteHeader = %d, want %d", sr.status, http.StatusNotFound)
+	}
+
+	// rec should also have the status set.
+	if rec.Code != http.StatusNotFound {
+		t.Errorf("rec.Code = %d, want %d", rec.Code, http.StatusNotFound)
+	}
+}
+
+func TestWithRequestLog(t *testing.T) {
+	handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusOK)
+	})
+
+	logger := slog.New(slog.NewTextHandler(io.Discard, nil))
+	wrapped := withRequestLog(handler, logger)
+	req := httptest.NewRequest(http.MethodGet, "/test", nil)
+	req.RemoteAddr = "192.168.1.1:12345"
+	rec := httptest.NewRecorder()
+
+	wrapped.ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusOK {
+		t.Errorf("status = %d, want 200", rec.Code)
+	}
+}