In most editors, you can double-click anywhere in the leading whitespace of a line to select all such leading whitespace (even mixed tab/space). In VS Code, double-clicking leading whitespace only selects that single whitespace character. Examples of expected behavior in Notepad++ and VS, and unexpected behavior in Code: 
In most editors, you can double-click anywhere in the leading whitespace of a line to select all such leading whitespace (even mixed tab/space).
In VS Code, double-clicking leading whitespace only selects that single whitespace character.
Examples of expected behavior in Notepad++ and VS, and unexpected behavior in Code: