Someone please name this matcher for me

Testing RSpec
1

I’ve had a matcher in my head for a couple months, that I frequently
want but never get around to writing because I can’t think of the name
for it. Here’s how it would look

[1, 2, 3, 4, 1].should … [1, 3, 1, 4, 2]

I have a couple ideas for names, but I’ll hold off on them so I don’t
influence anyone’s opinion.

btw, I realize that .sort works in this case. But that’s slightly
less clear than I’d like, and it doesn’t work for non-Comparable
objects (like activerecords).

Pat

2

perhaps verbose but how about

foo.should equal_in_any_order [1, 3, 1, 4, 2]

3

On Wed, Aug 6, 2008 at 1:50 PM, Pat M. [email protected] wrote:

less clear than I’d like, and it doesn’t work for non-Comparable
objects (like activerecords).

[1, 2, 3, 4, 1].should consist_of([1, 3, 1, 4, 2])

Since consist means “to be composed or made up of”, which matches the
usage.

To me it reads like, this thing should be made up of these other things.

WDYT?

–
Zach D.
http://www.continuousthinking.com

4

On Wed, Aug 6, 2008 at 12:50 PM, Pat M. [email protected] wrote:

I’ve had a matcher in my head for a couple months, that I frequently
want but never get around to writing because I can’t think of the name
for it. Here’s how it would look

[1, 2, 3, 4, 1].should … [1, 3, 1, 4, 2]

[1, 2, 3, 4, 1].should include_all [1, 3, 1, 4, 2]

5

Consider:
should_have_the_same_members_as

6

How about
[1, 2, 3, 4, 1].should contain([1, 3, 1, 4, 2])

[1, 2, 3, 4, 1].should contain_only([1, 3, 1, 4, 2])

or (riffing off Zach)

[1, 2, 3, 4, 1].should be_composed_from([1, 3, 1, 4, 2])

Matt

7

.should be_bag_of( [1, 3, 1, 4, 2] )

8

On Wed, 6 Aug 2008 13:50:27 -0400, you wrote:

I’ve had a matcher in my head for a couple months, that I frequently
want but never get around to writing because I can’t think of the name
for it. Here’s how it would look

[1, 2, 3, 4, 1].should … [1, 3, 1, 4, 2]

An unordered collection with possibly multiple occurrences of its
members is known in mathematics as a “multiset,” or, informally, a
“bag.”

-Steve

9

2008-08-06 13:11, Mike V.:

[1, 2, 3, 4, 1].should … [1, 3, 1, 4, 2]
[1, 2, 3, 4, 1].should include_all [1, 3, 1, 4, 2]

I’d then think that

[1, 1, 1, 2, 3, 4].should include_all [1, 3, 1, 4, 2]
[1, 2, 3, 4, 5, 6].should include_all [1, 3, 1, 4, 2]

Which afaik was not what Pat had in mind. Or was it?

And include_all_and_nothing_but is a bit verbose. :slight_smile:

10

2008-08-06 14:33, Steve Schafer:

An unordered collection with possibly multiple occurrences of its
members is known in mathematics as a “multiset,” or, informally, a
“bag.”

I (standing knee-deep in mathematics) was about to offer the following

be_multiset_equal_to
be_set_equal_to

Set equality is slightly (imo not fatally) incorrect, and multiset
might be alien to majority of hackers out there. I’d prefer either of
these or modifications.

11

On 07/08/2008, at 05:04 , Jonathan L. wrote:

.should be_bag_of( [1, 3, 1, 4, 2] )

FWIW, I am in favour of this naming. Now back to lurking :slight_smile:

12

On Wed, Aug 6, 2008 at 1:25 PM, Cohen, Joseph [email protected] wrote:

Consider:
should_have_the_same_members_as

Similarly, I have a have_same_elements_as(arr) matcher.

k

13

Lots of good, interesting suggestions.
If you don’t mind its length, for the non-mathematically inclined
something like

has_same_members_as

may be easier to remember and corresponds to Ruby’s member? predicate.

14

i wrote this matcher myself for a project i’m working on and have been
calling it `equals_without_regard_to_order’. it’s an unwieldy name
and i’ve never really been comfortable with it but i’ve continued to
use it, mostly because i’m dim.

very curious to find a winning replacement on this list!

–
Dhruv Bansal
http://www.infochimps.org || http://www.dhruvbansal.com ||
[email protected]

“Mark W.” [email protected] writes:

15

Zach D. wrote:

[1, 2, 3, 4, 1].should consist_of([1, 3, 1, 4, 2])

+1

16

Would such a matcher also work in this instance:

Car.should_receive(:find).with(bag_of[@ford.id, @fiat.id])

Such that if I don’t know (or care) what order the IDs will be passed to
the find method, this will pass?

Or is there already some other way to achieve that?

17

is_permutation_of would be technically correct, but it doesn’t really
express equality to me, which is the intent of the match.

///ark

18

On 07/08/2008, at 05:04 , Jonathan L. wrote:

.should be_bag_of( [1, 3, 1, 4, 2] )

+1