Ensuring typesafe

[smpa01]

how can I ensure, the function execution result returns same type as mentioned in the function?

let
    test_type = () as text=> "Hello",
    tbl = #table(type table [Name = text, Score = number], {{"Betty", 90.3}, {"Carl", 89.5}}),
    #"Added Custom" = Table.AddColumn(tbl, "Custom", each test_type())
    /*want to avoid doing below and the type needs to cascade from the function*/
    /*Table.AddColumn(tbl, "Custom", each test_type(), type text)*/
in
    #"Added Custom"

getting this

desire this

without requiring to do this

Table.AddColumn(tbl, "Custom", each test_type(), type text)

 @AlexisOlson @ImkeF 

[AlexisOlson · Accepted solution]

How about this?

= Table.AddColumn(tbl, "Custom", each test_type(), Value.Type(test_type()))

[smpa01]

Smashing

[nathancwatkins]

Why not first define the records, then build your #table by referring to the records and the the function, and assign the text type in the #table function itself?

--Nate