flutter doesn’t know whether the text is LTR or RTL, so you need to tell him the textDirection explicitly
new Text("Hello", textDirection: TextDirection.ltr)
or you can just wrap the Text with a Directionality Widget
new Directionality( textDirection: TextDirection.ltr, child: new Text('Hello')
and the purpuse of that is :
A widget that determines the ambient directionality of text and
text-direction-sensitive render objects.
And a Text widget in the scope of a MaterialApp widget does not need to be given an explicit writing direction because The default localization in the widgets and material libraries is LTR