Test2:...::Delta(3perl) Perl Programmers Reference GuideTest2:...::Delta(3perl)
NAME
Test2::Compare::Delta - Representation of differences between nested
data structures.
DESCRIPTION
This is used by Test2::Compare. When data structures are compared a
delta will be returned. Deltas are a tree data structure that represent
all the differences between two other data structures.
METHODS
CLASS METHODS
$class->add_column($NAME => sub { ... })
$class->add_column($NAME, %PARAMS)
This can be used to add columns to the table that it produced when a
comparison fails. The first argument should always be the column
name, which must be unique.
The first form simply takes a coderef that produces the value that
should be displayed in the column for any given delta. The arguments
passed into the sub are the delta, and the row ID.
Test2::Compare::Delta->add_column(
Foo => sub {
my ($delta, $id) = @_;
return $delta->... ? 'foo' : 'bar'
},
);
The second form allows you some extra options. The 'value' key is
required, and must be a coderef. All other keys are optional.
Test2::Compare::Delta->add_column(
'Foo', # column name
value => sub { ... }, # how to get the cell value
alias => 'FOO', # Display name (used in table header)
no_collapse => $bool, # Show column even if it has no values?
);
$bool = $class->remove_column($NAME)
This will remove the specified column. This will return true if the
column existed and was removed. This will return false if the column
did not exist. No exceptions are thrown. If a missing column is a
problem then you need to check the return yourself.
$class->set_column_alias($NAME, $ALIAS)
This can be used to change the table header, overriding the default
column names with new ones.
ATTRIBUTES
$bool = $delta->verified
$delta->set_verified($bool)
This will be true if the delta itself matched, if the delta matched
then the problem is in the delta's children, not the delta itself.
$aref = $delta->id
$delta->set_id([$type, $name])
ID for the delta, used to produce the path into the data structure.
An example is "['HASH' => 'foo']" which means the delta is in the
path "...->{'foo'}". Valid types are "HASH", "ARRAY", "SCALAR",
"META", and "METHOD".
$val = $delta->got
$delta->set_got($val)
Deltas are produced by comparing a received data structure 'got'
against a check data structure 'check'. The 'got' attribute contains
the value that was received for comparison.
$check = $delta->chk
$check = $delta->check
$delta->set_chk($check)
$delta->set_check($check)
Deltas are produced by comparing a received data structure 'got'
against a check data structure 'check'. The 'check' attribute
contains the value that was expected in the comparison.
"check" and "chk" are aliases for the same attribute.
$aref = $delta->children
$delta->set_children([$delta1, $delta2, ...])
A Delta may have child deltas. If it does then this is an arrayref
with those children.
$dne = $delta->dne
$delta->set_dne($dne)
Sometimes a comparison results in one side or the other not existing
at all, in which case this is set to the name of the attribute that
does not exist. This can be set to 'got' or 'check'.
$e = $delta->exception
$delta->set_exception($e)
This will be set to the exception in cases where the comparison
failed due to an exception being thrown.
OTHER
$string = $delta->render_got
Renders the string that should be used in a table to represent the
received value in a comparison.
$string = $delta->render_check
Renders the string that should be used in a table to represent the
expected value in a comparison.
$bool = $delta->should_show
This will return true if the delta should be shown in the table.
This is normally true for any unverified delta. This will also be
true for deltas that contain extra useful debug information.
$aref = $delta->filter_visible
This will produce an arrayref of "[ $path => $delta ]" for all
deltas that should be displayed in the table.
$aref = $delta->table_header
This returns an array ref of the headers for the table.
$string = $delta->table_op
This returns the operator that should be shown in the table.
$string = $delta->table_check_lines
This returns the defined lines (extra debug info) that should be
displayed.
$string = $delta->table_got_lines
This returns the generated lines (extra debug info) that should be
displayed.
$aref = $delta->table_rows
This returns an arrayref of table rows, each row is itself an
arrayref.
@table_lines = $delta->table
Returns all the lines of the table that should be displayed.
SOURCE
The source code repository for Test2-Suite can be found at
https://github.com/Test-More/Test2-Suite/.
MAINTAINERS
Chad Granum <exodist@cpan.org>
AUTHORS
Chad Granum <exodist@cpan.org>
COPYRIGHT
Copyright 2018 Chad Granum <exodist@cpan.org>.
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
See http://dev.perl.org/licenses/
perl v5.40.1 2026-08-30 Test2:...::Delta(3perl)
Generated by dwww version 1.16 on Sat Oct 3 07:36:58 CEST 2026.