Macro file

macro_rules! file {
    [_] => { ... };
    [_ : $type:ident] => { ... };
    [$path:literal] => { ... };
    [$path:literal : $type:ident] => { ... };
}

Declare an expected value for an assert from a file

This is relative to the source file the macro is run from

Output type: [Data]

file!["./test_data/bar.json"];
file!["./test_data/bar.json": Text];  // do textual rather than structural comparisons
file![_];
file![_: Json];  // ensure its treated as json since a type can't be inferred