1 files changed, 109 insertions, 0 deletions
diff --git a/internal/errors/errors_test.go b/internal/errors/errors_test.go
new file mode 100644
index 0000000..9193e38
--- /dev/null
+++ b/internal/errors/errors_test.go
@@ -0,0 +1,109 @@
+package errors
+
+import (
+	"errors"
+	"strings"
+	"testing"
+)
+
+func TestWrap(t *testing.T) {
+	tests := []struct {
+		name     string
+		err      error
+		msg      string
+		expected string
+	}{
+		{
+			name:     "wrap with message",
+			err:      ErrFileNotFound,
+			msg:      "opening config file",
+			expected: "opening config file: file not found",
+		},
+		{
+			name:     "wrap nil error",
+			err:      nil,
+			msg:      "should return nil",
+			expected: "",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := Wrap(tt.err, tt.msg)
+			if tt.err == nil && result != nil {
+				t.Errorf("expected nil, got %v", result)
+			}
+			if tt.err != nil && result.Error() != tt.expected {
+				t.Errorf("expected %q, got %q", tt.expected, result.Error())
+			}
+		})
+	}
+}
+
+func TestWrapf(t *testing.T) {
+	err := Wrapf(ErrConnectionFailed, "connecting to %s:%d", "localhost", 2222)
+	expected := "connecting to localhost:2222: connection failed"
+	if err.Error() != expected {
+		t.Errorf("expected %q, got %q", expected, err.Error())
+	}
+}
+
+func TestIs(t *testing.T) {
+	wrapped := Wrap(ErrPermissionDenied, "accessing /etc/passwd")
+	
+	if !Is(wrapped, ErrPermissionDenied) {
+		t.Error("expected Is to return true for wrapped error")
+	}
+	
+	if Is(wrapped, ErrFileNotFound) {
+		t.Error("expected Is to return false for different error")
+	}
+}
+
+func TestMultiError(t *testing.T) {
+	multi := NewMultiError()
+	
+	// Test empty multi-error
+	if multi.HasErrors() {
+		t.Error("new MultiError should not have errors")
+	}
+	if multi.ErrorOrNil() != nil {
+		t.Error("ErrorOrNil should return nil for empty MultiError")
+	}
+	
+	// Add errors
+	multi.Add(ErrConnectionFailed)
+	multi.Add(nil) // Should be ignored
+	multi.Add(ErrTimeout)
+	
+	if !multi.HasErrors() {
+		t.Error("MultiError should have errors after adding")
+	}
+	
+	if len(multi.Errors()) != 2 {
+		t.Errorf("expected 2 errors, got %d", len(multi.Errors()))
+	}
+	
+	// Test error message
+	errMsg := multi.Error()
+	if !strings.Contains(errMsg, "multiple errors occurred") {
+		t.Errorf("unexpected error message: %s", errMsg)
+	}
+	
+	// Test single error
+	single := NewMultiError()
+	single.Add(ErrInvalidArgument)
+	if single.Error() != "invalid argument" {
+		t.Errorf("single error message incorrect: %s", single.Error())
+	}
+}
+
+func TestErrorUnwrapping(t *testing.T) {
+	base := errors.New("base error")
+	wrapped := Wrap(base, "context")
+	
+	unwrapped := Unwrap(wrapped)
+	if unwrapped != base {
+		t.Error("Unwrap did not return base error")
+	}
+}
+\ No newline at end of file