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Re: [extremeperl] Testing, Audience, etc.

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  • Uwe Voelker
    ... Does the book only refer to bOP examples? It then would be like Instant CGI/Perl which relates to the Extropia web application framework. I would like to
    Message 1 of 20 , Jan 29, 2002
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      > I am writing to an advanced audience. To me, XPL is not for junior
      > programmers picking up a book and reading about it. It takes a lot of
      > sophistication to understand OO, customer-developer relationships, and
      > testing. There are a gadzillion perl shops out there with senior
      > people who just haven't been exposed to some of the ideas such as
      > declarative programming, but can easily understand them.



      Does the book only refer to bOP examples?

      It then would be like "Instant CGI/Perl" which relates to the Extropia
      web application framework.

      I would like to see also other examples that use the Perl Test::*
      modules. Or some of the GUI testing modules mentioned in the other
      mailing lists (I think it was 'Bricolage-Devel').


      >>yieah...
      >>
      >> return &{\&{'_inc_'.lc($self->get_name)}}($date_time);
      >>
      >>is an "improved" syntax?
      >>
      >
      > Yes. :) It embodies once and only once. You have to stare at it, but
      > it guarantees a number of good things:
      >
      > * dies if there is no implementation without having extra code
      > to say the same thing.
      > * dispatches correctly without chance of cut-and-paste errors.
      > * doesn't use temporary variables.
      > * is declarative


      Do you run it inside eval?
      For me, a dispatch table has other advantages: You can store additional
      information (like validation hooks, access privileges).
      Do you think temporary variables are bad?
      Why do you build a reference first and then dereference? I mean:
      return &{'_inc_'.lc($self->get_name)}($date_time);
      should also possible, or even
      ('_inc_'.lc($self->get_name))->($date_time);

      I am not so experienced, maybe I don't get the point.


      > I use int() with arrays. This seems the right place for it. scalar
      > doesn't place a type on the value, i.e.
      >
      > $second_arg = 35 if int(@_) < 3;


      So, you only use it, because it is more descriptive?


      Thank you,

      good bye, Uwe
    • Rob Nagler
      ... For the most part, yes. I am not particularly happy about it. My goal is to sell the idea that perl is an application programming language, and that it
      Message 2 of 20 , Jan 29, 2002
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        > Does the book only refer to bOP examples?

        For the most part, yes. I am not particularly happy about it. My
        goal is to sell the idea that perl is an application programming
        language, and that it is ideally suited to XP style development. When
        you read Java code, you see tremendous consistency. The style flows.
        We use CPAN quite a bit, but it isn't consistent. In particular the
        OO model is used inconsistently and naming is not uniform. In XP,
        the team writes code in one voice. If they don't, refactoring is
        more difficult.

        In no way do I mean that perl should be programmed in only one way.
        The team needs to agree on the way, but it can be any way.

        An important theme in the book is that declarative programming is the
        ultimate application of the once in only once principle, and that perl
        lets you program declaratively more easily than other imperative
        languages, e.g. VB, Java and C++. I just read an interesting quote:

        Programming languages teach you not to want to what they cannot
        provide. -- Paul Graham, ANSI Common Lisp

        The difference between bOP and other frameworks is that bOP tries hard
        to allow you program declaratively.

        > It then would be like "Instant CGI/Perl" which relates to the Extropia
        > web application framework.

        We released bOP not necessarily as a replacement for existing
        frameworks. Rather we released it to give our consulting group an
        anchor, and provide another example of how to program perl.

        I have never been afraid of writing infrastructure. We didn't write
        bOP in one day. It evolved over time. We had an end-to-end
        implementation running for our mail service within a month. The
        architecture has gone through many major revisions. For example, we
        just changed the basic object type from a hash_ref to an array_ref.

        > I would like to see also other examples that use the Perl Test::*
        > modules. Or some of the GUI testing modules mentioned in the other
        > mailing lists (I think it was 'Bricolage-Devel').

        I try to steer clear of stuff I don't know. I am not a GUI
        programmer, and I have very little experience testing GUIs. I talked
        about it a little bit, and included some references because it is an
        important topic.

        Another goal of the book is to keep it under 300 pages. I isn't a
        cookbook, or perl reference book. XPL is not revolutionary, it builds
        on a lot of existing material.

        > Do you run it inside eval?

        No.

        > For me, a dispatch table has other advantages: You can store additional
        > information (like validation hooks, access privileges).

        YAGNI. In this particular case, the dispatch table would have added
        more code, violated the once and only once principle, and probably be
        slower.

        > Do you think temporary variables are bad?

        Yes, unless you need them to save an expensive operation (no rules
        here). Temporary variables are state, and reliability is improved
        when all you have to deal with is stateless algorithms.

        One of the frustrations of functional programmers is that their
        systems are unpopular. To me, this is throwing out the baby with the
        bath water. There are a lot of great concepts in functional and
        declarative programming, which are obscured by their practitioners.
        Try to find a nonmathematical explanation of declarative programming.
        Most programmers are not mathematicians in the formal sense, and
        descriptions of the power of declarative programming are usually
        written for mathematicians. With the advent of XML, we are starting
        to see a change. Unfortunately, XML is a purely declarative language,
        and it suffers as a result. You can't program anything XML so now you
        need two languages at least to actually do something.

        In perl you can program imperatively, and create cool declarative
        interpreters. This allows you to create large applications with very
        little code, which is understandable by only knowing one language.

        > Why do you build a reference first and then dereference? I mean:
        > return &{'_inc_'.lc($self->get_name)}($date_time);
        > should also possible, or even
        > ('_inc_'.lc($self->get_name))->($date_time);

        We always use strict and -w. This requires you to build referenceduring,
        and then dereference it.

        >
        > > I use int() with arrays. This seems the right place for it. scalar
        > > doesn't place a type on the value, i.e.
        > >
        > > $second_arg = 35 if int(@_) < 3;
        >
        >
        > So, you only use it, because it is more descriptive?

        I guess so. perhaps all of the examples I have seen used int() on
        arrays. It seems intuitive to me as well.

        Cheers,
        Robthe
      • Tom Brown
        ... but it s not. An array in a scalar context is the number of elements in it. I don t need to tell you that, your knowledge of the language is better than
        Message 3 of 20 , Jan 29, 2002
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          > > >
          > > > $second_arg = 35 if int(@_) < 3;
          > >
          > >
          > > So, you only use it, because it is more descriptive?
          >
          > I guess so. perhaps all of the examples I have seen used int() on
          > arrays. It seems intuitive to me as well.

          but it's not. An array in a scalar context is the number of elements in
          it. I don't need to tell you that, your knowledge of the language is
          better than mine....

          adding the int() function makes me look at _why_ you are adding the
          function, and try to find the twist that needs it. There isn't one, so
          I've wasted time figuring that out. That is why I prefer either scalar()
          or nothing.

          Obviously, it's mostly a matter of style. Does it matter? I can't answer
          that. For the book to be used/popular you probably want to try to code to
          your target audience. No individual can claim to represent that.

          -Tom
        • Rob Nagler
          ... I m not so sure about that. ... Nothing like data to backup a hypothesis: trgrep bint (? s*@ /usr/lib/perl | grep -v Bivio | wc 6 trgrep
          Message 4 of 20 , Jan 29, 2002
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            Tom Brown writes:
            > but it's not. An array in a scalar context is the number of elements in
            > it. I don't need to tell you that, your knowledge of the language is
            > better than mine....

            I'm not so sure about that.

            > adding the int() function makes me look at _why_ you are adding the
            > function, and try to find the twist that needs it. There isn't one, so
            > I've wasted time figuring that out. That is why I prefer either scalar()
            > or nothing.

            Nothing like data to backup a hypothesis:

            trgrep '\bint\(?\s*@' /usr/lib/perl | grep -v Bivio | wc
            6

            trgrep '\bscalar\(?\s*@' /usr/lib/perl | grep -v Bivio | wc
            157

            The scalars have it. I'll change it to be nothing or scalar where
            required, thanks.

            > Obviously, it's mostly a matter of style. Does it matter? I can't answer
            > that. For the book to be used/popular you probably want to try to code to
            > your target audience. No individual can claim to represent that.

            This is the danger of writing a book about perl and XP. Whenever I
            mention that I program in perl at an XP meeting, I get the strangest
            looks. Fortunately, the perl community is more forgiving about XP.
            Yet they aren't the easiest audience to please either. :)

            Cheers,
            Rob
          • chromatic
            ... I ve had fairly good results combining the two. It s convincing free software folks to write tests that s tricky. -- chromatic
            Message 5 of 20 , Jan 29, 2002
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              On Tuesday 29 January 2002 13:15, you wrote:

              > This is the danger of writing a book about perl and XP. Whenever I
              > mention that I program in perl at an XP meeting, I get the strangest
              > looks. Fortunately, the perl community is more forgiving about XP.
              > Yet they aren't the easiest audience to please either. :)

              I've had fairly good results combining the two. It's convincing free
              software folks to write tests that's tricky.

              -- chromatic
            • Ged Haywood
              Hi Rob, ... I spent the better part of the previous two years doing both, for a system with something approaching 4 million users world-wide (IE and Netscape,
              Message 6 of 20 , Jan 29, 2002
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                Hi Rob,

                On Tue, 29 Jan 2002, Rob Nagler wrote:

                > I am not a GUI programmer, and I have very little experience testing GUIs.

                I spent the better part of the previous two years doing both, for a
                system with something approaching 4 million users world-wide (IE and
                Netscape, versions 4+ only). If there's anything you want to ask, do
                please ask. I won't know the answer.

                73,
                Ged.
              • Ed Grimm
                ... Correction: it s convincing *anybody* to write tests when they haven t learned to on their own that s tricky. I ve also noticed it s rather difficult to
                Message 7 of 20 , Feb 1 5:40 PM
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                  On Tue, 29 Jan 2002, chromatic wrote:
                  > On Tuesday 29 January 2002 13:15, you wrote:
                  >
                  >> This is the danger of writing a book about perl and XP. Whenever I
                  >> mention that I program in perl at an XP meeting, I get the strangest
                  >> looks. Fortunately, the perl community is more forgiving about XP.
                  >> Yet they aren't the easiest audience to please either. :)
                  >
                  > I've had fairly good results combining the two. It's convincing free
                  > software folks to write tests that's tricky.

                  Correction: it's convincing *anybody* to write tests when they haven't
                  learned to on their own that's tricky.

                  I've also noticed it's rather difficult to get a lot of XPers to
                  understand you can do it outside their chosen language. Except that I
                  have seen some Java XPers that seemed to understand you can do it in
                  SmallTalk.

                  Ed
                • drewbie74
                  Well, as a new convert to writing tests I can attest to your hypothesis. In general I have not sat down and written a good test suite when coding something
                  Message 8 of 20 , Feb 5 3:50 PM
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                    Well, as a new convert to writing tests I can attest to your
                    hypothesis. In general I have not sat down and written a good test
                    suite when coding something new. But I did so with a new module I
                    just wrote and I'm sold on the utility of tests.

                    Case in point. I wanted to make getting config vars case insensitive.
                    So I saved everything as lowercase hash keys. But this broke
                    something else, so I had to go back. Because I had tests, it was very
                    easy to see when everything was working correctly again. This benefit
                    alone is what really sold me on tests.

                    How to convince people to wite tests? Chromatic's article on perl.com
                    was excellent in showing HOW to write tests. Perhaps we need an short
                    article showing exactly how tests made a project easier? Heck, I've
                    got time, maybe I'll put something together...

                    Drew

                    --- In extremeperl@y..., chromatic <chromatic@r...> wrote:

                    > I've had fairly good results combining the two. It's convincing
                    free
                    > software folks to write tests that's tricky.
                    >
                    > -- chromatic
                  • chromatic
                    ... How about some brainstorming then? Here are several benefits of writing tests, in no particular order: - to clarify the intent of the code - to enforce
                    Message 9 of 20 , Feb 6 11:34 AM
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                      On Tuesday 05 February 2002 16:50, drewbie74 wrote:

                      > How to convince people to wite tests? Chromatic's article on perl.com
                      > was excellent in showing HOW to write tests. Perhaps we need an short
                      > article showing exactly how tests made a project easier? Heck, I've
                      > got time, maybe I'll put something together...

                      How about some brainstorming then? Here are several benefits of writing
                      tests, in no particular order:

                      - to clarify the intent of the code
                      - to enforce behavioral compatibility
                      - to explore boundary conditions
                      - to ensure that bugs have been corrected
                      - to ensure that bugs remain corrected
                      - to exercise an interface
                      - to help with decoupling (when writing code for testability)
                      - to add explanations of behavior (when using good test names with
                      Test::More)

                      There's obviously more (to make refactoring possible), but there's a
                      disturbing tendency to rewrite software from scratch, and I'm picking my
                      battles for now.

                      -- c
                    • Drew Taylor
                      ... Well, based on some work I did last night I have a prime example. I had written some modules previously that worked and are currently in production. Since
                      Message 10 of 20 , Feb 6 1:02 PM
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                        At 11:49 AM 2/6/2002 -0800, chromatic wrote:

                        >On Tuesday 05 February 2002 16:50, drewbie74 wrote:
                        >
                        > > How to convince people to wite tests? Chromatic's article on perl.com
                        > > was excellent in showing HOW to write tests. Perhaps we need an short
                        > > article showing exactly how tests made a project easier? Heck, I've
                        > > got time, maybe I'll put something together...
                        >
                        >How about some brainstorming then? Here are several benefits of writing
                        >tests, in no particular order:
                        >
                        > - to clarify the intent of the code
                        > - to enforce behavioral compatibility
                        > - to explore boundary conditions
                        > - to ensure that bugs have been corrected
                        > - to ensure that bugs remain corrected
                        > - to exercise an interface
                        > - to help with decoupling (when writing code for testability)
                        > - to add explanations of behavior (when using good test names with
                        >Test::More)
                        >
                        >There's obviously more (to make refactoring possible), but there's a
                        >disturbing tendency to rewrite software from scratch, and I'm picking my
                        >battles for now.
                        >
                        >-- c

                        Well, based on some work I did last night I have a prime example. I had
                        written some modules previously that worked and are currently in
                        production. Since there were no tests for said modules, I begun witing them
                        last night using Test::More (Thank you SO much Schwern - it rocks!). In the
                        process of doing so, I ended up doing some refactoring to make the modules
                        more flexible and worked out a couple of possible bugs. In the end, I had
                        better, more flexible, and refactored code that had good,comprehensive
                        tests - fulfilling the last 5 items in your list above. I was also forced
                        to setup a development environment (including a db) that had test data and
                        which I could use for testing purposes in perpetuity. This alone was worth
                        it's weight in gold.

                        For me, the acts of refactoring and writing tests now go hand in hand. Yes,
                        it takes time, sometimes a lot. But it is time well spent because it makes
                        your code better by the very nature of writing tests & making sure they
                        correctly run. It's hard to do one without the other because it's difficult
                        to make sure your "enhancement" isn't really a bug.

                        To address your last point, having tests helps keep me from rewriting code.
                        The tests help keep me from rewriting because I can fix only what is broken
                        or needs enhancing rather than thinking "This code is a bunch of crap!
                        Let's throw it out and just start over." Starting over is likely to
                        introduce more bugs than you fix. And this of course is exactly what you
                        were trying to avoid in the first place.

                        Oh geez, I hope I'm not becoming a zealot. Not that it would be a bad thing...


                        Well, based on some work I did last night I have a prime example. I had
                        written some modules previously that worked and are currently in
                        production. Since there were no tests for said modules, I begun witing them
                        last night using Test::More (Thank you SO much Schwern - it rocks!). In the
                        process of doing so, I ended up doing some refactoring to make the modules
                        more flexible and worked out a couple of possible bugs. In the end, I had
                        better, more flexible, and refactored code that had good,comprehensive
                        tests - fulfilling the last 5 items in your list above. I was also forced
                        to setup a development environment (including a db) that had test data and
                        which I could use for testing purposes in perpetuity. This alone was worth
                        it's weight in gold.

                        For me, the acts of refactoring and writing tests now go hand in hand. Yes,
                        it takes time, sometimes a lot. But it is time well spent because it makes
                        your code better by the very nature of writing tests & making sure they
                        correctly run. It's hard to do one without the other because it's difficult
                        to make sure your "enhancement" isn't really a bug.

                        To address your last point, having tests helps keep me from rewriting code.
                        The tests help keep me from rewriting because I can fix only what is broken
                        or needs enhancing rather than thinking "This code is a bunch of crap!
                        Let's throw it out and just start over." Starting over is likely to
                        introduce more bugs than you fix. And this of course is exactly what you
                        were trying to avoid in the first place.

                        Oh geez, I hope I'm not becoming a zealot. Not that it would be a bad thing...

                        Drew Taylor JA[P|m_p|SQL]H
                        http://www.drewtaylor.com/ Just Another Perl|mod_perl|SQL Hacker
                        mailto:drew@... *** God bless America! ***
                      • Rob Nagler
                        ... I like to distinguish between acceptance and unit tests. For unit tests, I would add: - to validate the API - to enable refactoring - to keep the cost of
                        Message 11 of 20 , Feb 6 2:35 PM
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                          Drew Taylor writes:
                          > At 11:49 AM 2/6/2002 -0800, chromatic wrote:
                          > >How about some brainstorming then? Here are several benefits of writing
                          > >tests, in no particular order:

                          I like to distinguish between acceptance and unit tests. For unit
                          tests, I would add:

                          - to validate the API
                          - to enable refactoring
                          - to keep the cost of change constant

                          A unit test suite is like a semantic compiler. In dynamic languages,
                          like Perl, there needs to be something to validate the code.

                          For acceptance tests, I would add:

                          - to encode concisely the domain knowledge of the customer
                          - to help the development team understand the problem

                          > Oh geez, I hope I'm not becoming a zealot. Not that it would be a bad thing...

                          Praise the Tests brother!

                          Rob
                        • Drew Taylor
                          Could you explain a little more about the two types of tests you mention below? Specifically the acceptance tests, and how they would relate to web apps. I m
                          Message 12 of 20 , Feb 6 3:07 PM
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                            Could you explain a little more about the two types of tests you mention
                            below? Specifically the acceptance tests, and how they would relate to web
                            apps. I'm trying to become more of an "architect", so a lot of the "domain
                            knowledge" stuff you & other texts mention is still a little fuzzy to me. I
                            read some of the docs on bivio, and it sounded very interesting.
                            Unfortunately more of it than I wanted was over my head. I'm very intrigued
                            about the platform you released and how to learn more about it in the
                            future - it would be a great learning tool for me.

                            It sounds like the tests I wrote last night would be unit tests as they
                            test object instantiation & the APIs.

                            Drew

                            At 03:35 PM 2/6/2002 -0700, Rob Nagler wrote:

                            >I like to distinguish between acceptance and unit tests. For unit
                            >tests, I would add:
                            >
                            >- to validate the API
                            >- to enable refactoring
                            >- to keep the cost of change constant
                            >
                            >A unit test suite is like a semantic compiler. In dynamic languages,
                            >like Perl, there needs to be something to validate the code.
                            >
                            >For acceptance tests, I would add:
                            >
                            >- to encode concisely the domain knowledge of the customer
                            >- to help the development team understand the problem

                            Drew Taylor JA[P|m_p|SQL]H
                            http://www.drewtaylor.com/ Just Another Perl|mod_perl|SQL Hacker
                            mailto:drew@... *** God bless America! ***
                          • Rob Nagler
                            ... There are many different kinds of tests including performance and load testing. In XP we re mostly concerned about unit and acceptance testing. ... What
                            Message 13 of 20 , Feb 6 9:52 PM
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                              Drew Taylor writes:
                              > Could you explain a little more about the two types of tests you mention
                              > below?

                              There are many different kinds of tests including performance and load
                              testing. In XP we're mostly concerned about unit and acceptance
                              testing.

                              > Specifically the acceptance tests, and how they would relate to web
                              > apps.

                              What is beautiful about the Web is that HTTP and HTML are a messaging
                              interface. You can build a complete acceptance test suite without
                              dealing with GUI scripting.

                              An acceptance test is a way of verifying end-user functions. A unit
                              test verifies programmer level functions. Both can test Web software.

                              > I'm trying to become more of an "architect",

                              Before you do, read this article:

                              http://joel.editthispage.com/stories/storyReader$320

                              One of the things I'm trying to learn is to become less of an architect.

                              > so a lot of the "domain
                              > knowledge" stuff you & other texts mention is still a little fuzzy
                              > to me.

                              Domain knowledge is simply "the problem". What I like about XP is
                              that it is problem-oriented, not solution-oriented.

                              > I
                              > read some of the docs on bivio, and it sounded very interesting.
                              > Unfortunately more of it than I wanted was over my head. I'm very intrigued
                              > about the platform you released and how to learn more about it in the
                              > future - it would be a great learning tool for me.

                              The great thing about perl is that lots of people have created lots of
                              code. We put out bOP, because it has no intrinsic value as a
                              product. There are just too many good toolkits out there. I consider
                              this a testament to perl more than anything else. You can create
                              incredibly solid software very quickly.

                              > It sounds like the tests I wrote last night would be unit tests as they
                              > test object instantiation & the APIs.

                              Yes, it sounds like you wrote unit tests. They are incredibly
                              important tools. We're slowly creating unit tests for our code. It's
                              tough to do, but we regret it every time we make changes and there is
                              no test to validate that we haven't broken anything.

                              Hope this helps.

                              Rob
                            • Drew Taylor
                              ... How do you do that? I ve only heard of tools that allow you to create a script and then playback that script. This is semiuseful, but what happens if you
                              Message 14 of 20 , Feb 6 10:33 PM
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                                At 10:52 PM 2/6/2002 -0700, Rob Nagler wrote:
                                >Drew Taylor writes:
                                > > Specifically the acceptance tests, and how they would relate to web
                                > > apps.
                                >
                                >What is beautiful about the Web is that HTTP and HTML are a messaging
                                >interface. You can build a complete acceptance test suite without
                                >dealing with GUI scripting.
                                >An acceptance test is a way of verifying end-user functions. A unit
                                >test verifies programmer level functions. Both can test Web software.

                                How do you do that? I've only heard of tools that allow you to create a
                                script and then playback that script. This is semiuseful, but what happens
                                if you make a change to the interface? What tools/techniques have you used
                                in the past to do acceptance testing? Do I have to setup a fake web server
                                environment & run the tests that way? That wouldn't be too difficult in a
                                CGI environment, and there are things like Apache::Fake now.

                                > > I'm trying to become more of an "architect",
                                >
                                >Before you do, read this article:
                                >
                                >http://joel.editthispage.com/stories/storyReader$320
                                >
                                >One of the things I'm trying to learn is to become less of an architect.

                                I hadn't seen that one before, although I have read some of Joel's other
                                articles. I'll read it tomorrow morning. My brief look says it will be
                                good. What I'm ultimately interested in learning is better design. Learning
                                patterns is one step, and working to see the problem from a higher level
                                view are two things I'm doing now.

                                > > so a lot of the "domain
                                > > knowledge" stuff you & other texts mention is still a little fuzzy
                                > > to me.
                                >
                                >Domain knowledge is simply "the problem". What I like about XP is
                                >that it is problem-oriented, not solution-oriented.

                                OK. Why don't they just say that? :-) I know that at high levels it's
                                essential that we're all speaking the same language, but can't that
                                language be simpler?

                                > > I
                                > > read some of the docs on bivio, and it sounded very interesting.
                                > > Unfortunately more of it than I wanted was over my head. I'm very
                                > intrigued
                                > > about the platform you released and how to learn more about it in the
                                > > future - it would be a great learning tool for me.
                                >
                                >The great thing about perl is that lots of people have created lots of
                                >code. We put out bOP, because it has no intrinsic value as a
                                >product. There are just too many good toolkits out there. I consider
                                >this a testament to perl more than anything else. You can create
                                >incredibly solid software very quickly.

                                This ability to quickly create a great product is one of the things that
                                really attracted me once I got serious about perl. I've seen several
                                frameworks that have interested me, including OpenInteract, OpenFrame, and
                                Mason. One day I hope I have the time to put some effort into learning each
                                better. I can just imagine all the tidbits of knowledge waiting to be
                                gleaned from each one.

                                > > It sounds like the tests I wrote last night would be unit tests as they
                                > > test object instantiation & the APIs.
                                >
                                >Yes, it sounds like you wrote unit tests. They are incredibly
                                >important tools. We're slowly creating unit tests for our code. It's
                                >tough to do, but we regret it every time we make changes and there is
                                >no test to validate that we haven't broken anything.

                                Yep, they were definitely unit tests. And as I mentioned before, I'm very
                                grateful I've written the ones I have because they did exactly what they're
                                supposed to do. Tell me when bugs appear and when they've been fixed. Once
                                I've gotten more tests done, I need to look into Test::Harness so I can run
                                them all at one swoop.

                                To illuistrate your last point, I have an example. At a previous employer,
                                we had a large codebase of perl modules (I bet it's probably doubled by
                                now) but no tests. I'm still close friends w/ the lead QA person and she
                                often just tests what she can and blindly hopes everything else still
                                works. It's just not possible to test every facet of the code for every
                                release (which is every 1-2 months). I really doubt that a comprehensive
                                test suite will ever be written, even though I have no doubt that it would
                                be an extremely important tool. The CTO's not convinced of the need, and I
                                don't think they would have/put the time to write a comprehensive suite
                                anyway. Besides, they're probably a little afraid of all the little bugs it
                                might turn up. ;-)

                                Could this be a hidden reason some shops are wary of tests?

                                Drew
                                Drew Taylor JA[P|m_p|SQL]H
                                http://www.drewtaylor.com/ Just Another Perl|mod_perl|SQL Hacker
                                mailto:drew@... *** God bless America! ***
                              • chromatic
                                ... If it s hidden, it s not hidden very well. :) Here s my take. Programmers don t want to write tests because: - it s not their job - it s not real
                                Message 15 of 20 , Feb 6 10:45 PM
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                                  On Wednesday 06 February 2002 23:33, Drew Taylor wrote:

                                  > The CTO's not convinced of the need, and I don't think they would have/put
                                  > the time to write a comprehensive suite anyway. Besides, they're probably a
                                  > little afraid of all the little bugs it might turn up. ;-)

                                  > Could this be a hidden reason some shops are wary of tests?

                                  If it's hidden, it's not hidden very well. :) Here's my take.

                                  Programmers don't want to write tests because:

                                  - it's not their job
                                  - it's not "real" coding
                                  - it's not as sexy as "real" coding
                                  - they don't know how
                                  - they don't know (or believe) the benefits
                                  - it's hard (but only the smart ones really believe this)

                                  Managers don't want coders to write tests because:

                                  - it takes time away from "real" coding
                                  - QA should handle it
                                  - it's cheaper to fix bugs when they're found

                                  I'm only sympathetic to the coders who don't yet know how and those who think
                                  writing tests is difficult. (I'll even propose that, unless you're adding
                                  tests to a system that has none, it *shouldn't* be difficult. If it is,
                                  you're not coding for testability and you're asking for trouble.)

                                  Okay, my analyst hat is off. Feel free to jump on this thread with
                                  evangelism if anyone has questions.

                                  * * * * *

                                  As for your Test::Harness question, use h2xs to make a skeleton Makefile.PL
                                  for your project. Put your tests in the t/ subdirectory, edit the @INC paths
                                  if needed, and run 'perl Makefile.PL; make; make test' and it should Just
                                  Work.

                                  Now you know just about as much as I care to remember about the whole process.

                                  -- c
                                • Drew Taylor
                                  ... All your points are right on the money. I would venture to guess that most good programmers would not be against writing tests. IMHO, it s usually
                                  Message 16 of 20 , Feb 7 9:05 AM
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                                    At 11:45 PM 2/6/2002 -0700, chromatic wrote:

                                    ><snip> excellent points </snip>

                                    >I'm only sympathetic to the coders who don't yet know how and those who think
                                    >writing tests is difficult. (I'll even propose that, unless you're adding
                                    >tests to a system that has none, it *shouldn't* be difficult. If it is,
                                    >you're not coding for testability and you're asking for trouble.)

                                    All your points are right on the money. I would venture to guess that most
                                    "good" programmers would not be against writing tests. IMHO, it's usually
                                    managements edicts & timelines that forces the lack of tests. As for the
                                    last point, I read somewhere (perhaps in one of Steve McConnell's books)
                                    that a study found it takes magnitudes of more time/money to fix a bug
                                    after the fact that to fix it before. And if it negatively affects a
                                    customer, then multiply that cost by several factors for pissed off said
                                    customer. If only management could be made to understand this fact, getting
                                    tests would be much simpler. If I ever get a fulltime job again, I
                                    certainly will push for good tests, even if it's just unit tests.

                                    I was once one of those people who didn't understand how easy it is to
                                    write tests. Yes, it took some time to get a good test environment setup,
                                    but it was worth the few hous it took. And now I can easily and _quickly_
                                    add new tests. Modules like Test::Simple & Test::More are the key.

                                    >As for your Test::Harness question, use h2xs to make a skeleton Makefile.PL
                                    >for your project. Put your tests in the t/ subdirectory, edit the @INC paths
                                    >if needed, and run 'perl Makefile.PL; make; make test' and it should Just
                                    >Work.

                                    That's almost too easy... But then, this IS perl we're talking about. :-)

                                    [OT] As an aside, why is it that when I do Reply TO All in Eudora that the
                                    mailing list is on the to line twice, rather than the poster & the list?
                                    It's rather annoying since that is my usual behavior. Or is this considered
                                    bad form? I've never gotten a good answer on this question.

                                    Drew
                                    Drew Taylor JA[P|m_p|SQL]H
                                    http://www.drewtaylor.com/ Just Another Perl|mod_perl|SQL Hacker
                                    mailto:drew@... *** God bless America! ***
                                  • Ged Haywood
                                    Hi all, ... [snip] ... See attached. I once had to fly to seven or eight different countries over a period of several weeks to fix a $0.25 problem in a couple
                                    Message 17 of 20 , Feb 7 5:11 PM
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                                      Hi all,

                                      On Thu, 7 Feb 2002, Drew Taylor wrote:

                                      > At 11:45 PM 2/6/2002 -0700, chromatic wrote:
                                      [snip]
                                      > managements edicts & timelines that forces the lack of tests. As for the
                                      > last point, I read somewhere (perhaps in one of Steve McConnell's books)
                                      > that a study found it takes magnitudes of more time/money to fix a bug
                                      > after the fact that to fix it before. And if it negatively affects a
                                      > customer, then multiply that cost by several factors for pissed off said
                                      > customer. If only management could be made to understand this fact...

                                      See attached.

                                      I once had to fly to seven or eight different countries over a period
                                      of several weeks to fix a $0.25 problem in a couple of hundred $22,000
                                      instruments because the guy in procurement had ignored my written
                                      procurement specification and the guy in test had ignored my written
                                      test secification. The problems only started to surface when the
                                      instruments were used in hot places.

                                      It still bugs me that I didn't send a bill to their employer, who was
                                      my supplier and contracted to make the things to the specification.

                                      It's called experience.

                                      73,
                                      Ged.


                                      [Non-text portions of this message have been removed]
                                    • Rob Nagler
                                      ... The first step is to make sure your interface has structure. If you are testing arbitrarily constructed templates, you re going to have a rough time. If
                                      Message 18 of 20 , Feb 8 4:41 PM
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                                        > How do you do that? I've only heard of tools that allow you to create a
                                        > script and then playback that script. This is semiuseful, but what happens
                                        > if you make a change to the interface?

                                        The first step is to make sure your interface has structure. If you
                                        are testing arbitrarily constructed templates, you're going to have a
                                        rough time. If you build your HTML pages from widgets or
                                        parameterized templates, you'll have some structure to grab on to.

                                        > What tools/techniques have you used
                                        > in the past to do acceptance testing?

                                        The best tool is perl. We used it to test our CORBA based Web server,
                                        and we use it to test our application written in perl. It is not very
                                        hard to build an acceptance test suite using tools like LWP and
                                        HTMLParser.

                                        I am a little behind schedule. My goal is to release our internal
                                        infrastructure by the end of the month. It will come with a test
                                        suite which tests our pet shop demo (http://petshop.bivio.biz).

                                        > Do I have to setup a fake web server
                                        > environment & run the tests that way?

                                        I find for acceptance testing you need a test environment which is as
                                        close to your production environment as possible. Any of our
                                        developers can run the test suite on their personal Web servers.
                                        Every night we run the test suite against our test servers, which are
                                        relatively clean machines.

                                        > good. What I'm ultimately interested in learning is better design. Learning
                                        > patterns is one step, and working to see the problem from a higher level
                                        > view are two things I'm doing now.

                                        To me, there are two sides: analysis and synthesis. Patterns are
                                        about synthesis. XP is about analysis. I'm not a big fan of
                                        patterns, because they're very focused on classical object-oriented
                                        programming, and I try to program declaratively whenever I can. In
                                        addition, languages like Java, have some serious deficiencies such as
                                        weak ability to delegate and no class level inheritance.

                                        I find reading books about Lisp, functional programming, and logic
                                        programming expands my solution set much better than reading a book
                                        about design patterns.

                                        > OK. Why don't they just say that? :-) I know that at high levels it's
                                        > essential that we're all speaking the same language, but can't that
                                        > language be simpler?

                                        It is really hard to write cogent prose, which addresses a wide
                                        audience. They're just some concepts which are hard to explain in
                                        simpler language. I'm reading a book by Einstein which is incredibly
                                        well written but I have a really hard time understanding his
                                        discussions about the special theory and general theory of
                                        relativity. That's why I'm a programmer, I guess.

                                        > anyway. Besides, they're probably a little afraid of all the little bugs it
                                        > might turn up. ;-)
                                        >
                                        > Could this be a hidden reason some shops are wary of tests?

                                        I don't think so. In general, people have a hard time quantifying
                                        quality. If it works in the general case, it may be enough. The user
                                        base may be small. I really like Gerry Weinberg's comments on quality
                                        in his book "Quality Software Management: Vol. 1 Systems Thinking":

                                        The Quality Statement: Every statement about quality is a statement about some
                                        person(s).

                                        The Political Dilemma: More quality for one person may mean less
                                        quality for another.

                                        The Quality Decision: Whose opinion of quality is to count when making
                                        decisions?

                                        The Inadequate Definition of Quality: Quality is the absence of error.

                                        The Absence of Errors Fallacy: Though copious errors guarantees
                                        worthlessness, having zero errors guarantees nothing at all about the
                                        value of software.

                                        I highly recommend the book.

                                        Rob
                                      • Stas Bekman
                                        ... Since you are talking about testing apps against webserver, I d plug in the new Apache::Test framework which most Apache::* modules and frameworks
                                        Message 19 of 20 , Feb 21 3:37 AM
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                                          Rob Nagler wrote:

                                          >>What tools/techniques have you used
                                          >>in the past to do acceptance testing?
                                          >>
                                          >
                                          > The best tool is perl. We used it to test our CORBA based Web server,
                                          > and we use it to test our application written in perl. It is not very
                                          > hard to build an acceptance test suite using tools like LWP and
                                          > HTMLParser.
                                          >
                                          > I am a little behind schedule. My goal is to release our internal
                                          > infrastructure by the end of the month. It will come with a test
                                          > suite which tests our pet shop demo (http://petshop.bivio.biz).
                                          >
                                          >
                                          >>Do I have to setup a fake web server
                                          >>environment & run the tests that way?
                                          >>
                                          >
                                          > I find for acceptance testing you need a test environment which is as
                                          > close to your production environment as possible. Any of our
                                          > developers can run the test suite on their personal Web servers.
                                          > Every night we run the test suite against our test servers, which are
                                          > relatively clean machines.

                                          Since you are talking about testing apps against webserver, I'd plug in
                                          the new Apache::Test framework which most Apache::* modules' and
                                          frameworks' developers will find very helpful. The goal is to have every
                                          Apache::* module needing mod_perl or just plain apache env, use
                                          Apache::Test for its test. There is no more excuses for not having
                                          tests. And if something is missing from its functionality now it's the
                                          time to jump in and ask for it/add it.

                                          httpd-test project is using this Perl framework for testing C modules
                                          for Apache 1.3 and 2.0 and the server itself. And of course originally
                                          it was developed for mod_perl 2.0. The same test suite can work with
                                          httpd 1.3 and httpd 2.0. For more info see:
                                          http://perl.apache.org/preview/modperl-site/docs/2.0/devel/testing/testing.html

                                          Once we release the new modperl site (hopefully in a few weeks) this URL
                                          will appear as:
                                          http://perl.apache.org/docs/2.0/devel/testing/testing.html

                                          I've started mentioning XP in this doc and mention reasons for a need to
                                          test, but more work in needed so your help is very welcome.

                                          To get the framework grab the httpd-test rep from cvs or the snapshot:
                                          http://cvs.apache.org/snapshots/modperl-2.0/

                                          also see:
                                          http://cvs.apache.org/viewcvs.cgi/httpd-test/perl-framework/README?rev=1.8&content-type=text/vnd.viewcvs-markup

                                          _____________________________________________________________________
                                          Stas Bekman JAm_pH -- Just Another mod_perl Hacker
                                          http://stason.org/ mod_perl Guide http://perl.apache.org/guide
                                          mailto:stas@... http://ticketmaster.com http://apacheweek.com
                                          http://singlesheaven.com http://perl.apache.org http://perlmonth.com/
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