library ieee;
    use ieee.std_logic_1164.all;
    use ieee.numeric_std.all;
    use ieee.float_pkg.all;

library std;
    use std.textio.all;

package test_utility is
    constant TEST_FAIL : string := "[ FAIL ]";
    constant TEST_OK : string := "[ OK ]" & LF;

    type real_array is array ( natural range <> ) of real;

    procedure assert_eq( a : in std_logic_vector; b : in std_logic_vector );

    procedure assert_near( variable a : in real;
        variable b : in real;
        variable abs_err : in real );

    procedure assert_element_near( variable a : in real;
        variable b : in real;
        variable abs_err : in real;
        variable index : in integer );

end package test_utility;

package body test_utility is

    procedure assert_eq( a : in std_logic_vector; b : in std_logic_vector ) is
    begin

        assert( a = b )
            report TEST_FAIL & "assert_eq" & LF &
                "    a: " & to_string( a ) & LF &
                "    b: " & to_string( b ) & LF
                severity error;
    end procedure assert_eq;

    procedure assert_near( variable a : in real;
        variable b : in real;
        variable abs_err : in real ) is
        variable abs_diff : real;
    begin
        abs_diff := abs( a - b );
        assert( abs_diff <= abs_err )
            report TEST_FAIL & "assert_near" & LF &
                "    a: " & to_string( a ) & LF &
                "    b: " & to_string( b ) & LF &
                "    " & to_string( abs_diff ) & " > " & to_string( abs_err ) & LF
                severity error;
    end procedure assert_near;

    procedure assert_element_near( variable a : in real;
        variable b : in real;
        variable abs_err : in real;
        variable index : in integer ) is
        variable abs_diff : real;
    begin
        abs_diff := abs( a - b );
        assert( abs_diff <= abs_err )
            report TEST_FAIL & "assert_element_near" & LF &
                "    element: " & integer'image( index ) & LF &
                "    a: " & to_string( a ) & LF &
                "    b: " & to_string( b ) & LF &
                "    " & to_string( abs_diff ) & " > " & to_string( abs_err ) & LF
                severity error;
    end procedure assert_element_near;

end package body test_utility;