Test::More how come?

sem999 has asked for the wisdom of the Perl Monks concerning the following question:

Test::More confuse me;

1. the code

#!/usr/local/bin/perl

use Test::More;

print "4 - 2 = " , ( 4 - 2 ) . "\n";

cmp_ok ( 4 - 2 , '==', 2, "maths works" );

print "\n";

print "-2.3 - -0.6 = " . ( -2.3 - -0.6 ) ."\n";

cmp_ok ( -2.3 - -0.6 , '==', -1.7, "maths works" );

done_testing();
[download]

2. the output

# ./p.pl
4 - 2 = 2
ok 1 - maths works

-2.3 - -0.6 = -1.7
not ok 2 - maths works
#   Failed test 'maths works'
#   at ./p.pl line 13.
#          got: -1.7
#     expected: -1.7
1..2
# Looks like you failed 1 test of 2.
[download]

Comment on Test::More how come? Select or Download Code

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Re: Test::More how come? by tmharish (Friar) on Jan 30, 2013 at 17:10 UTC
Generally STDOUT does not show up with `make test` You can use diag or print STDERR : `#!/usr/local/bin/perl use Test::More; print STDERR "4 - 2 = " , ( 4 - 2 ) . "\n"; cmp_ok ( 4 - 2 , '==', 2, "maths works" ); print STDERR "\n"; print STDERR "-2.3 - -0.6 = " . ( -2.3 - -0.6 ) ."\n"; cmp_ok ( -2.3 - -0.6 , '==', -1.7, "maths works" ); done_testing();` [download]	[reply] [d/l] [select]
Re^2: Test::More how come? by sem999 (Initiate) on Jan 30, 2013 at 17:13 UTC
Sure, but don't you think the second test should PASS? have i made some really simple mistake but just can't see it??	[reply]
Re^3: Test::More how come? by keszler (Priest) on Jan 30, 2013 at 17:24 UTC
Try: `perl -e 'printf "%.32g\n", -2.3 - -0.6;' -1.6999999999999997` [download] See for other examples Perl 5.8.x floating point representation error, RFC: Large Floating Point Numbers - Rounding Errors, etc.	[reply] [d/l]
Re^3: Test::More how come? by thmsdrew (Scribe) on Jan 30, 2013 at 17:26 UTC
It'll work if you use `eq` instead of `==`.	[reply] [d/l] [select]
Re^4: Test::More how come? by sem999 (Initiate) on Jan 30, 2013 at 17:44 UTC
Re^3: Test::More how come? by tmharish (Friar) on Jan 30, 2013 at 17:20 UTC
Ah!! I misunderstood! ( and miss read! ) Operator Precedence maybe?	[reply]
Re^4: Test::More how come? by soonix (Chancellor) on Jan 30, 2013 at 17:26 UTC