Add comprehensive test suite with unit and integration tests

message_test.go

@@ -0,0 +1,285 @@
+package sendamatic
+
+import (
+	"encoding/base64"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestNewMessage(t *testing.T) {
+	msg := NewMessage()
+
+	if msg == nil {
+		t.Fatal("NewMessage returned nil")
+	}
+
+	if msg.To == nil || msg.CC == nil || msg.BCC == nil {
+		t.Error("Slices not initialized")
+	}
+
+	if msg.Headers == nil || msg.Attachments == nil {
+		t.Error("Headers or Attachments not initialized")
+	}
+}
+
+func TestMessageBuilderMethods(t *testing.T) {
+	msg := NewMessage().
+		SetSender("sender@example.com").
+		AddTo("to@example.com").
+		AddCC("cc@example.com").
+		AddBCC("bcc@example.com").
+		SetSubject("Test Subject").
+		SetTextBody("Test Body").
+		SetHTMLBody("<p>Test Body</p>").
+		AddHeader("X-Custom", "value")
+
+	if msg.Sender != "sender@example.com" {
+		t.Errorf("Sender = %q, want %q", msg.Sender, "sender@example.com")
+	}
+
+	if len(msg.To) != 1 || msg.To[0] != "to@example.com" {
+		t.Errorf("To = %v, want [to@example.com]", msg.To)
+	}
+
+	if len(msg.CC) != 1 || msg.CC[0] != "cc@example.com" {
+		t.Errorf("CC = %v, want [cc@example.com]", msg.CC)
+	}
+
+	if len(msg.BCC) != 1 || msg.BCC[0] != "bcc@example.com" {
+		t.Errorf("BCC = %v, want [bcc@example.com]", msg.BCC)
+	}
+
+	if msg.Subject != "Test Subject" {
+		t.Errorf("Subject = %q, want %q", msg.Subject, "Test Subject")
+	}
+
+	if msg.TextBody != "Test Body" {
+		t.Errorf("TextBody = %q, want %q", msg.TextBody, "Test Body")
+	}
+
+	if msg.HTMLBody != "<p>Test Body</p>" {
+		t.Errorf("HTMLBody = %q, want %q", msg.HTMLBody, "<p>Test Body</p>")
+	}
+
+	if len(msg.Headers) != 1 {
+		t.Fatalf("Headers length = %d, want 1", len(msg.Headers))
+	}
+
+	if msg.Headers[0].Header != "X-Custom" || msg.Headers[0].Value != "value" {
+		t.Errorf("Header = %+v, want {X-Custom value}", msg.Headers[0])
+	}
+}
+
+func TestAddMultipleRecipients(t *testing.T) {
+	msg := NewMessage().
+		AddTo("to1@example.com").
+		AddTo("to2@example.com").
+		AddTo("to3@example.com")
+
+	if len(msg.To) != 3 {
+		t.Errorf("To length = %d, want 3", len(msg.To))
+	}
+
+	expected := []string{"to1@example.com", "to2@example.com", "to3@example.com"}
+	for i, email := range expected {
+		if msg.To[i] != email {
+			t.Errorf("To[%d] = %q, want %q", i, msg.To[i], email)
+		}
+	}
+}
+
+func TestAttachFile(t *testing.T) {
+	msg := NewMessage()
+	data := []byte("test file content")
+
+	msg.AttachFile("test.txt", "text/plain", data)
+
+	if len(msg.Attachments) != 1 {
+		t.Fatalf("Attachments length = %d, want 1", len(msg.Attachments))
+	}
+
+	att := msg.Attachments[0]
+	if att.Filename != "test.txt" {
+		t.Errorf("Filename = %q, want %q", att.Filename, "test.txt")
+	}
+
+	if att.MimeType != "text/plain" {
+		t.Errorf("MimeType = %q, want %q", att.MimeType, "text/plain")
+	}
+
+	// Verify base64 encoding
+	decoded, err := base64.StdEncoding.DecodeString(att.Data)
+	if err != nil {
+		t.Fatalf("Failed to decode base64: %v", err)
+	}
+
+	if string(decoded) != string(data) {
+		t.Errorf("Decoded data = %q, want %q", decoded, data)
+	}
+}
+
+func TestAttachFileFromPath(t *testing.T) {
+	msg := NewMessage()
+
+	testFile := filepath.Join("testdata", "test.txt")
+	err := msg.AttachFileFromPath(testFile, "text/plain")
+	if err != nil {
+		t.Fatalf("AttachFileFromPath failed: %v", err)
+	}
+
+	if len(msg.Attachments) != 1 {
+		t.Fatalf("Attachments length = %d, want 1", len(msg.Attachments))
+	}
+
+	att := msg.Attachments[0]
+	if att.Filename != "test.txt" {
+		t.Errorf("Filename = %q, want %q", att.Filename, "test.txt")
+	}
+
+	// Verify content
+	decoded, err := base64.StdEncoding.DecodeString(att.Data)
+	if err != nil {
+		t.Fatalf("Failed to decode base64: %v", err)
+	}
+
+	expected, _ := os.ReadFile(testFile)
+	if string(decoded) != string(expected) {
+		t.Errorf("File content mismatch")
+	}
+}
+
+func TestAttachFileFromPath_NonExistent(t *testing.T) {
+	msg := NewMessage()
+
+	err := msg.AttachFileFromPath("nonexistent.txt", "text/plain")
+	if err == nil {
+		t.Error("Expected error for non-existent file, got nil")
+	}
+}
+
+func TestAttachMultipleFiles(t *testing.T) {
+	msg := NewMessage().
+		AttachFile("file1.txt", "text/plain", []byte("content1")).
+		AttachFile("file2.pdf", "application/pdf", []byte("content2"))
+
+	if len(msg.Attachments) != 2 {
+		t.Errorf("Attachments length = %d, want 2", len(msg.Attachments))
+	}
+}
+
+func TestValidate_Success(t *testing.T) {
+	tests := []struct {
+		name string
+		msg  *Message
+	}{
+		{
+			name: "valid with text body",
+			msg: NewMessage().
+				SetSender("sender@example.com").
+				AddTo("to@example.com").
+				SetSubject("Subject").
+				SetTextBody("Body"),
+		},
+		{
+			name: "valid with html body",
+			msg: NewMessage().
+				SetSender("sender@example.com").
+				AddTo("to@example.com").
+				SetSubject("Subject").
+				SetHTMLBody("<p>Body</p>"),
+		},
+		{
+			name: "valid with both bodies",
+			msg: NewMessage().
+				SetSender("sender@example.com").
+				AddTo("to@example.com").
+				SetSubject("Subject").
+				SetTextBody("Body").
+				SetHTMLBody("<p>Body</p>"),
+		},
+		{
+			name: "valid with multiple recipients",
+			msg: NewMessage().
+				SetSender("sender@example.com").
+				AddTo("to1@example.com").
+				AddTo("to2@example.com").
+				AddCC("cc@example.com").
+				AddBCC("bcc@example.com").
+				SetSubject("Subject").
+				SetTextBody("Body"),
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			err := tt.msg.Validate()
+			if err != nil {
+				t.Errorf("Validate() error = %v, want nil", err)
+			}
+		})
+	}
+}
+
+func TestValidate_Errors(t *testing.T) {
+	tests := []struct {
+		name        string
+		msg         *Message
+		wantErrText string
+	}{
+		{
+			name:        "no recipients",
+			msg:         NewMessage().SetSender("sender@example.com").SetSubject("Subject").SetTextBody("Body"),
+			wantErrText: "at least one recipient required",
+		},
+		{
+			name:        "no sender",
+			msg:         NewMessage().AddTo("to@example.com").SetSubject("Subject").SetTextBody("Body"),
+			wantErrText: "sender is required",
+		},
+		{
+			name:        "no subject",
+			msg:         NewMessage().SetSender("sender@example.com").AddTo("to@example.com").SetTextBody("Body"),
+			wantErrText: "subject is required",
+		},
+		{
+			name:        "no body",
+			msg:         NewMessage().SetSender("sender@example.com").AddTo("to@example.com").SetSubject("Subject"),
+			wantErrText: "either text_body or html_body is required",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			err := tt.msg.Validate()
+			if err == nil {
+				t.Fatal("Validate() error = nil, want error")
+			}
+			if err.Error() != tt.wantErrText {
+				t.Errorf("Validate() error = %q, want %q", err.Error(), tt.wantErrText)
+			}
+		})
+	}
+}
+
+func TestValidate_TooManyRecipients(t *testing.T) {
+	msg := NewMessage().
+		SetSender("sender@example.com").
+		SetSubject("Subject").
+		SetTextBody("Body")
+
+	// Add 256 recipients (more than the limit of 255)
+	for i := 0; i < 256; i++ {
+		msg.AddTo("recipient@example.com")
+	}
+
+	err := msg.Validate()
+	if err == nil {
+		t.Fatal("Validate() error = nil, want error for too many recipients")
+	}
+
+	expected := "maximum 255 recipients allowed"
+	if err.Error() != expected {
+		t.Errorf("Validate() error = %q, want %q", err.Error(), expected)
+	}
+}