if.t

use v6;

use Test;

plan 29;

=begin kwid

Basic "if" tests.


=end kwid

# L<S04/Conditional statements>

my $x = 'test';
if ($x eq $x) { pass('if ($x eq $x) {} works'); } else { flunk('if ($x eq $x) {} failed'); }
if ($x ne $x) { flunk('if ($x ne $x) {} failed'); } else { pass('if ($x ne $x) {} works'); }
if (1) { pass('if (1) {} works'); } else { flunk('if (1) {} failed'); }
if (0) { flunk('if (0) {} failed'); } else { pass('if (0) {} works'); }
if (Mu) { flunk('if (Mu) {} failed'); } else { pass('if (Mu) {} works'); }

{
    # die called in the condition part of an if statement should die immediately
    # rather than being evaluated as true
    my $foo = 1;
    try { if (die "should die") { $foo = 3 } else { $foo = 2; } };
    #say '# $foo = ' ~ $foo;
    is $foo, 1, "die should stop execution immediately.";
}

{
    my $foo = 1; # just in case
    if 1 > 2 { $foo = 2 } else { $foo = 3 };
    is $foo, 3, 'if with no parens';
};

# if...elsif
{
    my $foo = 1;
    if (1) { $foo = 2 } elsif (1) { $foo = 3 };
    is $foo, 2, 'if (1) {} elsif (1) {}';
}

{
    my $foo = 1;
    if (1) { $foo = 2 } elsif (0) { $foo = 3 };
    is $foo, 2, 'if (1) {} elsif (0) {}';
}

{
    my $foo = 1;
    if (0) { $foo = 2 } elsif (1) { $foo = 3 };
    is $foo, 3, 'if (0) {} elsif (1) {}';
}

{
    my $foo = 1;
    if (0) { $foo = 2 } elsif (0) { $foo = 3 };
    is $foo, 1, 'if (0) {} elsif (0) {}';
}


# if...elsif...else

{
    my $foo = 1;
    if (0) { $foo = 2 } elsif (0) { $foo = 3 } else { $foo = 4 };
    is $foo, 4;
}

{
    my $foo = 1;
    if (1) { $foo = 2 } elsif (0) { $foo = 3 } else { $foo = 4 };
    is $foo, 2;
}

{
    my $foo = 1;
    if (1) { $foo = 2 } elsif (1) { $foo = 3 } else { $foo = 4 };
    is $foo, 2;
}

{
    my $foo = 1;
    if (0) { $foo = 2 } elsif (1) { $foo = 3 } else { $foo = 4 };
    is $foo, 3;
}

{
    my $foo = 1;
    if ({ 1 > 0 }) { $foo = 2 } else { $foo = 3 };
    is $foo, 2, 'if with parens, and closure as cond';
}

{
    my $var = 9;
    my sub func( $a, $b, $c ) { $var };    #OK not used
    if func 1, 2, 3 { $var = 4 } else { $var = 5 };
    is $var, 4, 'if with no parens, and call a function without parenthesis';
}

# I'm not sure where this should go

{
    my $flag = 0;
    if ( my $x = 2 ) == 2 { $flag = $x }
    is($flag, 2, "'my' variable within 'if' conditional");
}

{
    eval_dies_ok('if 1; 2', '"if" requires a block');
}

# L<S04/"Conditional statements"/The value of the conditional expression may be optionally bound to a closure parameter>
{
    my ($got, $a_val, $b_val);
    my sub testa { $a_val };
    my sub testb { $b_val };

    $a_val = 'truea';
    $b_val = 0;
    if    testa() -> $a { $got = $a }
    elsif testb() -> $b { $got = $b }
    else          -> $c { $got = $c }
    is $got, 'truea', 'if test() -> $a { } binding';

    $a_val = 0;
    $b_val = 'trueb';
    if    testa() -> $a { $got = $a }
    elsif testb() -> $b { $got = $b }
    else          -> $c { $got = $c }
    is $got, 'trueb', 'elsif test() -> $b { } binding';

    $a_val = '';
    $b_val = 0;
    if    testa() -> $a { $got = $a }
    elsif testb() -> $b { $got = $b }
    else          -> $c { $got = $c }
    is $got, 0, 'else -> $c { } binding previous elsif';

    $a_val = '';
    $b_val = 0;
    if    testa() -> $a { $got = $a }
    else          -> $c { $got = $c }
    is $got, '', 'else -> $c { } binding previous if';
}

{
    my $called = 0;
    sub cond($when) {
        is $called,$when,"condition is checked in correct order";
        $called++;
        0;
    }
    if cond(0) {
    } elsif cond(1) {
    } elsif cond(2) {
    }
    is $called,3,"all conditions are checked";
}


# L<S04/Statement parsing/keywords require whitespace>
eval_dies_ok('if($x > 1) {}','keyword needs at least one whitespace after it');

# RT #76174
# scoping of $_ in 'if' shouldn't break aliasing
{
    my @a = 0, 1, 2;
    for @a { if $_ { $_++ } };
    is ~@a, '0 2 3', '"if" does not break lexical aliasing of $_'
}

# vim: ft=perl6