Respect TypeModifierOmitStackTrace in Builder

Previous implementation of `WithCause` method didn't respect the
`TypeModifierOmitStackTrace` modifier. A stack trace was erroneously
collected if the error that was passed to `WithCause` didn't have
stack trace.

builder.go

@@ -33,12 +33,12 @@ func NewErrorBuilder(t *Type) ErrorBuilder {
 }
 
 // WithCause provides an original cause for error.
-// For non-errorx errors, a stack trace is collected.
+// For non-errorx errors, a stack trace is collected unless Type tells otherwise.
 // Otherwise, it is inherited by default, as error wrapping is typically performed 'en passe'.
 // Note that even if an original error explicitly omitted the stack trace, it could be added on wrap.
 func (eb ErrorBuilder) WithCause(err error) ErrorBuilder {
 	eb.cause = err
-	if Cast(err) != nil {
+	if eb.errorType.modifiers.CollectStackTrace() && Cast(err) != nil {
 		eb.mode = stackTraceBorrow
 	}
 

builder_test.go

@@ -20,3 +20,33 @@ func TestBuilderTransparency(t *testing.T) {
 		require.NotEqual(t, testType, err.Type())
 	})
 }
+
+func TestBuilderRespectsNoStackTrace(t *testing.T) {
+	wrapperErrorTypes := []*Type{testTypeSilent, testTypeSilentTransparent}
+
+	for _, et := range wrapperErrorTypes {
+		t.Run(et.String(), func(t *testing.T) {
+			t.Run("Naked", func(t *testing.T) {
+				err := NewErrorBuilder(et).
+					WithCause(errors.New("naked error")).
+					Create()
+				require.Nil(t, err.stackTrace)
+			})
+
+			t.Run("WithoutStacktrace", func(t *testing.T) {
+				err := NewErrorBuilder(et).
+					WithCause(testTypeSilent.NewWithNoMessage()).
+					Create()
+				require.Nil(t, err.stackTrace)
+			})
+
+			t.Run("WithStacktrace", func(t *testing.T) {
+				err := NewErrorBuilder(et).
+					WithCause(testType.NewWithNoMessage()).
+					Create()
+				require.Nil(t, err.stackTrace)
+			})
+		})
+	}
+
+}

error_test.go

@@ -9,14 +9,15 @@ import (
 )
 
 var (
-	testNamespace       = NewNamespace("foo")
-	testType            = testNamespace.NewType("bar")
-	testTypeSilent      = testType.NewSubtype("silent").ApplyModifiers(TypeModifierOmitStackTrace)
-	testTypeTransparent = testType.NewSubtype("transparent").ApplyModifiers(TypeModifierTransparent)
-	testSubtype0        = testType.NewSubtype("internal")
-	testSubtype1        = testSubtype0.NewSubtype("wat")
-	testTypeBar1        = testNamespace.NewType("bar1")
-	testTypeBar2        = testNamespace.NewType("bar2")
+	testNamespace             = NewNamespace("foo")
+	testType                  = testNamespace.NewType("bar")
+	testTypeSilent            = testType.NewSubtype("silent").ApplyModifiers(TypeModifierOmitStackTrace)
+	testTypeTransparent       = testType.NewSubtype("transparent").ApplyModifiers(TypeModifierTransparent)
+	testTypeSilentTransparent = testType.NewSubtype("silent_transparent").ApplyModifiers(TypeModifierTransparent, TypeModifierOmitStackTrace)
+	testSubtype0              = testType.NewSubtype("internal")
+	testSubtype1              = testSubtype0.NewSubtype("wat")
+	testTypeBar1              = testNamespace.NewType("bar1")
+	testTypeBar2              = testNamespace.NewType("bar2")
 )
 
 func TestError(t *testing.T) {