feat: enhanced error handling module

internal/gperr/multiline_test.go

@@ -0,0 +1,38 @@
+package gperr
+
+import (
+	"net"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestMultiline(t *testing.T) {
+	multiline := Multiline()
+	multiline.Addf("line 1 %s", "test")
+	multiline.Adds("line 2")
+	multiline.AddLines([]any{1, "2", 3.0, net.IPv4(127, 0, 0, 1)})
+	t.Error(New("result").With(multiline))
+	t.Error(multiline.Subject("subject").Withf("inner"))
+}
+
+func TestWrapMultiline(t *testing.T) {
+	multiline := Multiline()
+	var wrapper error = wrap(multiline)
+	_, ok := wrapper.(*MultilineError)
+	if !ok {
+		t.Errorf("wrapper is not a MultilineError")
+	}
+}
+
+func TestPrependSubjectMultiline(t *testing.T) {
+	multiline := Multiline()
+	multiline.Addf("line 1 %s", "test")
+	multiline.Adds("line 2")
+	multiline.AddLines([]any{1, "2", 3.0, net.IPv4(127, 0, 0, 1)})
+	multiline.Subject("subject")
+
+	builder := NewBuilder()
+	builder.Add(multiline)
+	require.Equal(t, len(builder.errs), len(multiline.Extras), builder.errs)
+}