I'm a TDDer and often have a need to refactor out common or similar code. Similar code is not always a result of copy and paste.
I'm not looking for tools to identify the regions or suspected duplications, there are a number of tools to do that. And if the code is exactly the same there is no big problem, Eclipse can almost always do that by itself.
I am looking for tools to visualize differences of sections of code that are radically different, but my human eye can see the structural similarities, and could possibly be made even more similar, so that the common code eventually could be factored out.
It would be very handy if there was a possibility to mark two regions and get Eclipse (or some other tool) to mark the differences. With this information it would be much simpler to iteratively move the regions closer until they are the same and then activate the Extract Method refactoring.
It can be done in Emacs of course, but I'd like to have this readily available from Eclipse. Any pointers?
Seems there was somewhat usable answers in this question, a question articulating the same need. But, again those answers focus on finding duplications, not vizualising it.
Two suggestions that works are KDiff3 and Diffuse. Both allow you to open up the same file twice or paste different sections in the panes. There seems to be no way to use them from Eclipse though.
I don not know of a way to mark regions and diff them in eclipse, but you can diff two files. In that way you might get what you are looking for by copying out the parts you want to diff in two paste files, at least 90%?
Select the two files you want to diff in the project tree and right-click -> select compare with -> each other.
cheers,
Jørgen
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I have two 1000+ line programs in Perl, each with about 20 subroutines in the main file. One was forked from the other some time ago and I want to factor out the common parts (before porting features backward.) Is there a diff tool that will treat the subroutines (and preceding comments) as units, and extract the common units into a new file? (if one line of a subroutine is different, the unit doesn’t match.)
My SCM is currently Subversion if that helps. A Perl script that processes the code would be cool.
You can try to use the PPI module; to my knowledge there's no tool for refactoring as the one you mentioned.
If you had 500,000 lines of code it might be useful to have or write such a tool. For 1000 lines, this shouldn't be too hard with a simple visual diff tool, like BeyondCompare ($) or WinMerge (free).
You're trying to compare two different versions of the files?
I use VIM which comes with a built in diff program vimdiff and a fully gui one called gvimdiff. It'll fold common lines and just show you the lines that differ and where.
With gvim, you can open up three splits in one window (the two versions and a blank) and then copy over the various lines you want. If you're using Subversion, you can use the built in merge tool (if you're talking about different versions of the same file). The Subversion merge is pretty good and will probably help you with the merge issues.
I'm looking for some tool/library that would scan given project tree, and report on code duplicates - i.e. blocks of code that are repeated in various files.
Is there anything like this?
As it is now, I have to view them (files) all, and search for duplicates, but it doesn't strike me as very efficient.
A System for Detecting Software Plagiarism might work; it supports Perl.
And here's a list.
Is there any diff tool for Lotus Notes which allows to compare scripts, design elements and documents?
I see this is an old question, and most of the other answers are a little outdated now, so I thought I would add some hopefully valuable information for those who should stumble upon this now.
In Domino Designer, open either the Navigator or Package Explorer (Window menu -> Show Eclipse Views). Here you can expand databases/templates to see the design elements they contain. Select two or three elements (CTRL-click). They can be in different databases or the same database. Right click on one of the elements and select Compare with -> Each other.
You can also compare two databases element by element by selecting two databases/templates, right-clicking and selecting Compare with -> Each other. You will then get the differences between the two databases listed. You will be able to see which elements differ between the two databases, and which elements exist in one database but not the other. By double-clicking on a differing element, you will open a diff tool which lets you see differences line by line, and you can easily copy changes from left to right or right to left.
There is a tool from TeamStudio called Delta: http://www.teamstudio.com/products/delta.html
If all else fails (and by "all else" I mean the often ridiculous corporate procurement system) you can always do a an export to DXL (or a Design Synopsis for code alone) and use any decent text editor with a diff function. It's not TeamStudio Delta, but it will get you where you want to go.
There is a free tool from OpenNTF which does document comparisons:
http://www.openntf.org/Projects/pmt.nsf/ProjectLookup/Compare%20Notes%20Documents
Ytria also has a product which, among other things, will compare data documents (I don't believe it compares design elements).
http://www.ytria.com/website.nsf/WebPageRequest/Solutions_scanEZ_specen
And, I believe Martin Scott (http://www.martinscott.com) has a similar product which compares documents.
DDE (Domino Designer on Eclipse) let's you compare design elements natively. Same way as the search. It's pretty efficient (faster than a DXL exportation) and it's free.
I had a discussion on my blog a little while back about this:
http://rosshawkins.net/archive/2009/12/24/notesdomino-refactoringanalysis-tools.aspx
However what I've ended up doing in the past is exporting the design to the filesystem and using standard text tools (WinMerge and SublimeText for me personally) to do what I need.
Being able to do the raw dump is something that was added with the Eclipse based designer, and isn't overly obvious, but you can read more about it here:
rosshawkins.net/archive/2010/01/20/searching-the-contents-of-notesdomino-design-elements.aspx
(link mangled as my rep is too low to post 2 links in one post yet!)
Teamstudio Delta is really nice. However it might kill you with too many details. As Ross pointed out the Domino Designer 8.5 can use the Diff tool inherited from Eclipse. You also could head over to http://www.openntf.org and look for the DXLMagic project. It can generate a report that shows differences (including code) between 2 databases (typically a template and a variation of it). It is not as complete as Delta, but shows the essentials. It's free and source is included (Disclaimer: I wrote it).
This is what I do. I run a design synopsis of the database using the Notes Designer. Dump the file to a text file. You can actually split the synopsis out to different objects like Agents, Forms, Views, etc. Then you can run UNIX/Linux/Mac Unix commands to compare the elements. By doing this operation you find out what code is active, and have a complete documented source code. You do a lot of csplit and a few sed commands.
Version 12.0.1 has such a tool as part of the server. Look for comparedbs.ntf and designsynopsis.ntf on the Domino server.
I have a lot of HTML files (10,000's and GBs worth) scraped from a server and I want to check to make sure the server produces the same results after some modifications but ignore kinds of differences that don't matter, e.g. whitespace, missing newlines, timestamps, small changes in some kinds of number, etc.
Does anyone know of a tool for doing this? I'd really rather not do more filtering than I have to.
(Oh and it needs to run under linux)
You might consider using a clone detector such as our CloneDR. This tool parses large sets of computer program (HTML is special case) files, builds abstract syntax trees representing the essential structure of each files, and compares programs for similarity.
Because it is comparing essential program structure, it ignores inessential differences such as comments and whitespace, and deterimines that two code segments are either identical or one can be obtained from the other by substituting other blocks of code. The latter allows the recognition of code that has been modified in various ways. You can see samples of clone detection runs on a variety of computer languages at the web site.
In your case, what you would be looking for are files in system A which are essentially clones (exact or near misses) of files in system B. As a general rule, if a file a is a variant of file b (e.g., with a few changes) the CloneDr will report it as a clone and show the exact differences.
At the scale of 20,000 files, I can see why you want a tool, and I can see why you want near-miss matches rather than exact matches.
Doesn't run under Linux, but I assume your problem is hard to enough to solve so that isn't what you are optimizing.
I use winmerge alot in windows and from what i can see some people enjoy meld in linux, so perhaps that could do the trick for you
http://meld.sourceforge.net/
Other examples i saw from a quick googling was Kompare,xxdiff.sourceforge.net, and kdiff3.sourceforge.net
(could only post 1 link so wrote the adresses to xxdiff and kdiff3 as text)
Beyond Compare is purchased software that is actually worth the money (I never thought I'd hear myself typing that!). It is GUI based but handles thousands of files very well. It will allow you to specify unimportant changes with regular expressions as well as whitespace (beginning, middle and end of line). The feature set is very extensive, check out a trial download.
I do not work for this company, I just use Beyond Compare every day at work and enjoy it every time!
What source control products have a "diff" facility that ignores white space, braces, etc., in calculating the difference between checked-in versions? I seem to remember that Clearcase's diff did this but Visual SourceSafe (or at least the version I used) did not.
The reason I ask is probably pretty typical. Four perfectly reasonable developers on a team have four entirely different ways of formatting their code. Upon checking out the code last changed by someone else, each will immediately run some kind of program or editor macro to format things the way they like. They make actual code changes. They check-in their changes. They go on vacation. Two days later that program, which had been running fine for two years, blows up. The developer assigned to the bug does a diff between versions and finds 204 differences, only 3 of which are of any significance, because the diff algorithm is lame.
Yes, you can have coding standards. Most everyone finds them dreadful. A solution where everyone can have their cake and eat it too seems far more preferable.
=========
EDIT: Thanks to everyone for some great suggestions.
What I take away from this is:
(1) A source control system with plug-in type diffs is preferable.
(2) Find a diff with suitable options.
(3) Use a good source formatting program and settle on a check-in standard.
Sounds like a plan. Thanks again.
Git does have these options:
--ignore-space-at-eol
Ignore changes in whitespace at EOL.
-b, --ignore-space-change
Ignore changes in amount of whitespace. This ignores whitespace at line end, and considers all other sequences of one or more
whitespace characters to be equivalent.
-w, --ignore-all-space
Ignore whitespace when comparing lines. This ignores differences even if one line has whitespace where the other line has
none.
I am not sure if brace changes can be ignored using Git's diff.
If it is C/C++ code, you can define Astyle rules and then convert the source code's brace style to the one that you want, using Astyle. A git diff will then produce sane output.
Choose one (dreadful) coding standard, write it down in some official coding standards document, and get on with your life, messing with whitespace is not productive work.
And remember you are a professional developer, it's your job to get the project done, changing anything in the code because of a personal style preference hurts the project - it wont only make diff-ing more difficult, it can also introduce hard to find problems if your source formatter or compiler has bugs (and your fancy diff tool won't save you when two co-worker start fighting over casing).
And if someone just doesn't agree to work with the selected style just remind him (or her) that he is programming as a profession not as an hobby, see http://www.ericsink.com/entries/No_Great_Hackers.html
Maybe you should choose one format and run some indentation tool before checking in so that each person can check out, reformat to his/her own preferences, do the changes, reformat back to the official standard and then check in?
A couple of extra steps but they already use indentation tools when working. Maybe it can be a triggered check-in script?
Edit: this would perhaps also solve the brace problem.
(I haven't tried this solution myself, hence the "perhapes" and "maybes", but I have been in projects with the same problems, and it is a pain to try to go through diffs with hundreds of irrelevant changes that are not limited to whitespace, but includes the formatting itself.)
As explained in Is it possible for git-merge to ignore line-ending differences?, it is more a matter to associate the right diff tool to your favorite VCS, rather than to rely on the right VCS option (even if Git does have some options regarding whitespace, like the one mentioned in Alan's answer, it will always be not as complete as one would like).
DiffMerge is the more complete on those "ignore" options, as it can not only ignore spaces but also other "variations" based on the programming language used in a given file.
Subversion apparently supports this, either natively in the latest versions, or by using an alternate diff like Gnu Diff.
Beyond Compare does this (and much much more) and you can integrate it either in Subversion or Sourcesafe as an external diff tool.