Code action DR008 (Readability) Simplify multi-variable block
Description
A variable block with multiple variables where each is a simple measure reference, which are only used once in the RETURN section without any context modifiers, should be simplified.
Example
Change:
VAR _sales = [Total Sales]
VAR _cost = [Total Cost]
RETURN
_sales - _cost
To:
[Total Sales] - [Total Cost]
Why is Tabular Editor suggesting this?
A common pattern in DAX is to declare a variable for each measure that is used in a calculation. This is a good practice when the value of a measure is needed in multiple places in the calculation (for performance reasons). However, when each such variable is used exactly once in the RETURN part of the code, in an evaluation context that would not change the result of the measure, there is no need to declare the variables at all. Instead, referencing the measures directly in the calculation should be preferred to make the code more concise and easier to read.
Remarks:
The DAX Debugger in Tabular Editor 3 will show the values of measures used in the calculation within the Locals view. This makes it easy to inspect the values of the measures during debugging, even when their values are not stored in variables.