Refactor senderror_test.go for improved test clarity

Consolidated multiple duplicate test cases into grouped sub-tests with clear names. This enhances readability and maintainability, ensures proper test isolation, and removes redundant code.

senderror_test.go

@@ -6,17 +6,17 @@ package mail
 
 import (
 	"errors"
-	"fmt"
 	"strings"
 	"testing"
 )
 
 // TestSendError_Error tests the SendError and SendErrReason error handling methods
 func TestSendError_Error(t *testing.T) {
-	tl := []struct {
-		n  string
-		r  SendErrReason
-		te bool
+	t.Run("TestSendError_Error with various reasons", func(t *testing.T) {
+		tests := []struct {
+			name   string
+			reason SendErrReason
+			isTemp bool
 		}{
 			{"ErrGetSender/temp", ErrGetSender, true},
 			{"ErrGetSender/perm", ErrGetSender, false},
@@ -43,126 +43,173 @@ func TestSendError_Error(t *testing.T) {
 			{"Unknown/temp", 9999, true},
 			{"Unknown/perm", 9999, false},
 		}
-
-	for _, tt := range tl {
-		t.Run(tt.n, func(t *testing.T) {
-			if err := returnSendError(tt.r, tt.te); err != nil {
-				exp := &SendError{Reason: tt.r, isTemp: tt.te}
-				if !errors.Is(err, exp) {
-					t.Errorf("error mismatch, expected: %s (temp: %t), got: %s (temp: %t)", tt.r, tt.te,
-						exp.Error(), exp.isTemp)
+		for _, tt := range tests {
+			t.Run(tt.name, func(t *testing.T) {
+				err := returnSendError(tt.reason, tt.isTemp)
+				if err == nil {
+					t.Fatalf("error expected, got nil")
 				}
-				if !strings.Contains(fmt.Sprintf("%s", err), tt.r.String()) {
+				want := &SendError{Reason: tt.reason, isTemp: tt.isTemp}
+				if !errors.Is(err, want) {
+					t.Errorf("error mismatch, expected: %s (temp: %t), got: %s (temp: %t)",
+						tt.reason, tt.isTemp, want.Error(), want.isTemp)
+				}
+				if !strings.Contains(err.Error(), tt.reason.String()) {
 					t.Errorf("error string mismatch, expected: %s, got: %s",
-						tt.r.String(), fmt.Sprintf("%s", err))
-				}
+						tt.reason.String(), err.Error())
 				}
 			})
 		}
+	})
+	t.Run("TestSendError_Error with multiple errors", func(t *testing.T) {
+		message := testMessage(t)
+		err := &SendError{
+			affectedMsg: message,
+			errlist:     []error{ErrNoRcptAddresses, ErrNoFromAddress},
+			rcpt:        []string{"<toni.tester@domain.tld>", "<tina.tester@domain.tld>"},
+			Reason:      ErrAmbiguous,
+		}
+		if !strings.Contains(err.Error(), "ambiguous reason, check Msg.SendError for message specific reasons") {
+			t.Errorf("error string mismatch, expected: ambiguous reason, check Msg.SendError for message "+
+				"specific reasons, got: %s", err.Error())
+		}
+		if !strings.Contains(err.Error(), "no recipient addresses set, no FROM address set") {
+			t.Errorf("error string mismatch, expected: no recipient addresses set, no FROM address set, got: %s",
+				err.Error())
+		}
+		if !strings.Contains(err.Error(), "affected recipient(s): <toni.tester@domain.tld>, "+
+			"<tina.tester@domain.tld>") {
+			t.Errorf("error string mismatch, expected: affected recipient(s): <toni.tester@domain.tld>, "+
+				"<tina.tester@domain.tld>, got: %s", err.Error())
+		}
+	})
+}
+
+func TestSendError_Is(t *testing.T) {
+	t.Run("TestSendError_Is errors match", func(t *testing.T) {
+		err1 := returnSendError(ErrAmbiguous, false)
+		err2 := returnSendError(ErrAmbiguous, false)
+		if !errors.Is(err1, err2) {
+			t.Error("error mismatch, expected ErrAmbiguous to be equal to ErrAmbiguous")
+		}
+	})
+	t.Run("TestSendError_Is errors mismatch", func(t *testing.T) {
+		err1 := returnSendError(ErrAmbiguous, false)
+		err2 := returnSendError(ErrSMTPMailFrom, false)
+		if errors.Is(err1, err2) {
+			t.Error("error mismatch, ErrAmbiguous should not be equal to ErrSMTPMailFrom")
+		}
+	})
+	t.Run("TestSendError_Is on nil", func(t *testing.T) {
+		var err *SendError
+		if err.Is(ErrNoFromAddress) {
+			t.Error("expected false on nil-senderror")
+		}
+	})
 }
 
 func TestSendError_IsTemp(t *testing.T) {
-	var se *SendError
-	err1 := returnSendError(ErrAmbiguous, true)
-	if !errors.As(err1, &se) {
-		t.Errorf("error mismatch, expected error to be of type *SendError")
-		return
+	t.Run("TestSendError_IsTemp is true", func(t *testing.T) {
+		err := returnSendError(ErrAmbiguous, true)
+		if err == nil {
+			t.Fatalf("error expected, got nil")
 		}
-	if errors.As(err1, &se) && !se.IsTemp() {
-		t.Errorf("error mismatch, expected temporary error")
-		return
+		var sendErr *SendError
+		if !errors.As(err, &sendErr) {
+			t.Fatal("error expected to be of type *SendError")
 		}
-	err2 := returnSendError(ErrAmbiguous, false)
-	if !errors.As(err2, &se) {
-		t.Errorf("error mismatch, expected error to be of type *SendError")
-		return
+		if !sendErr.IsTemp() {
+			t.Errorf("expected temporary error, got: temperr: %t", sendErr.IsTemp())
 		}
-	if errors.As(err2, &se) && se.IsTemp() {
-		t.Errorf("error mismatch, expected non-temporary error")
-		return
+	})
+	t.Run("TestSendError_IsTemp is false", func(t *testing.T) {
+		err := returnSendError(ErrAmbiguous, false)
+		if err == nil {
+			t.Fatalf("error expected, got nil")
 		}
-}
-
-func TestSendError_IsTempNil(t *testing.T) {
+		var sendErr *SendError
+		if !errors.As(err, &sendErr) {
+			t.Fatal("error expected to be of type *SendError")
+		}
+		if sendErr.IsTemp() {
+			t.Errorf("expected permanent error, got: temperr: %t", sendErr.IsTemp())
+		}
+	})
+	t.Run("TestSendError_IsTemp is nil", func(t *testing.T) {
 		var se *SendError
 		if se.IsTemp() {
 			t.Error("expected false on nil-senderror")
 		}
+	})
 }
 
 func TestSendError_MessageID(t *testing.T) {
-	var se *SendError
+	t.Run("TestSendError_MessageID message ID is set", func(t *testing.T) {
+		var sendErr *SendError
 		err := returnSendError(ErrAmbiguous, false)
-	if !errors.As(err, &se) {
-		t.Errorf("error mismatch, expected error to be of type *SendError")
-		return
+		if !errors.As(err, &sendErr) {
+			t.Fatal("error mismatch, expected error to be of type *SendError")
 		}
-	if errors.As(err, &se) {
-		if se.MessageID() == "" {
-			t.Errorf("sendError expected message-id, but got empty string")
+		if sendErr.MessageID() == "" {
+			t.Error("sendError expected message-id, but got empty string")
 		}
-		if !strings.EqualFold(se.MessageID(), "<this.is.a.message.id>") {
+		if !strings.EqualFold(sendErr.MessageID(), "<this.is.a.message.id>") {
 			t.Errorf("sendError message-id expected: %s, but got: %s", "<this.is.a.message.id>",
-				se.MessageID())
+				sendErr.MessageID())
 		}
+	})
+	t.Run("TestSendError_MessageID message ID is not set", func(t *testing.T) {
+		var sendErr *SendError
+		message := testMessage(t)
+		err := &SendError{
+			affectedMsg: message,
+			errlist:     []error{ErrNoRcptAddresses},
+			rcpt:        []string{"<toni.tester@domain.tld>", "<tina.tester@domain.tld>"},
+			Reason:      ErrAmbiguous,
 		}
-}
-
-func TestSendError_MessageIDNil(t *testing.T) {
-	var se *SendError
-	if se.MessageID() != "" {
-		t.Error("expected empty string on nil-senderror")
+		if !errors.As(err, &sendErr) {
+			t.Fatal("error mismatch, expected error to be of type *SendError")
 		}
+		if sendErr.MessageID() != "" {
+			t.Errorf("sendError expected empty message-id, got: %s", sendErr.MessageID())
+		}
+	})
 }
 
 func TestSendError_Msg(t *testing.T) {
-	var se *SendError
+	t.Run("TestSendError_Msg message is set", func(t *testing.T) {
+		var sendErr *SendError
 		err := returnSendError(ErrAmbiguous, false)
-	if !errors.As(err, &se) {
-		t.Errorf("error mismatch, expected error to be of type *SendError")
-		return
+		if !errors.As(err, &sendErr) {
+			t.Fatal("error mismatch, expected error to be of type *SendError")
 		}
-	if errors.As(err, &se) {
-		if se.Msg() == nil {
-			t.Errorf("sendError expected msg pointer, but got nil")
+		msg := sendErr.Msg()
+		if msg == nil {
+			t.Fatalf("sendError expected msg pointer, but got nil")
 		}
-		from := se.Msg().GetFromString()
+		from := msg.GetFromString()
 		if len(from) == 0 {
-			t.Errorf("sendError expected msg from, but got empty string")
-			return
+			t.Fatal("sendError expected msg from, but got empty string")
 		}
 		if !strings.EqualFold(from[0], "<toni.tester@domain.tld>") {
 			t.Errorf("sendError message from expected: %s, but got: %s", "<toni.tester@domain.tld>",
 				from[0])
 		}
-	}
-}
-
-func TestSendError_MsgNil(t *testing.T) {
-	var se *SendError
-	if se.Msg() != nil {
-		t.Error("expected nil on nil-senderror")
-	}
-}
-
-func TestSendError_IsFail(t *testing.T) {
-	err1 := returnSendError(ErrAmbiguous, false)
-	err2 := returnSendError(ErrSMTPMailFrom, false)
-	if errors.Is(err1, err2) {
-		t.Errorf("error mismatch, ErrAmbiguous should not be equal to ErrSMTPMailFrom")
-	}
-}
-
-func TestSendError_ErrorMulti(t *testing.T) {
-	expected := `ambiguous reason, check Msg.SendError for message specific reasons, ` +
-		`affected recipient(s): <email1@domain.tld>, <email2@domain.tld>`
+	})
+	t.Run("TestSendError_Msg message is not set", func(t *testing.T) {
+		var sendErr *SendError
 		err := &SendError{
-		Reason: ErrAmbiguous, isTemp: false, affectedMsg: nil,
-		rcpt: []string{"<email1@domain.tld>", "<email2@domain.tld>"},
+			errlist: []error{ErrNoRcptAddresses},
+			rcpt:    []string{"<toni.tester@domain.tld>", "<tina.tester@domain.tld>"},
+			Reason:  ErrAmbiguous,
 		}
-	if err.Error() != expected {
-		t.Errorf("error mismatch, expected: %s, got: %s", expected, err.Error())
+		if !errors.As(err, &sendErr) {
+			t.Fatal("error mismatch, expected error to be of type *SendError")
 		}
+		if sendErr.Msg() != nil {
+			t.Errorf("sendError expected nil msg pointer, got: %v", sendErr.Msg())
+		}
+	})
 }
 
 // returnSendError is a helper method to retunr a SendError with a specific reason
@@ -173,6 +220,5 @@ func returnSendError(r SendErrReason, t bool) error {
 	message.Subject("This is the subject")
 	message.SetBodyString(TypeTextPlain, "This is the message body")
 	message.SetMessageIDWithValue("this.is.a.message.id")
-
 	return &SendError{Reason: r, isTemp: t, affectedMsg: message}
 }