Git pre-commit hooks
Git's pre-commit hooks are pretty useful. You could use them, for instance, to run your tests and abort the commit if there are failures. All you have to do is write a simple shellscript. The example below runs a php syntax check on all php files and aborts the commit if it detects anything invalid. It's based on a script that was going around at $work, no idea who the original author is, but kudos!
Save this as .git/pre-commit, and make sure you make it executable (chmod u+x)!
#!/bin/sh
syntax_errors=0
error_msg=$(mktemp /tmp/error_msg.XXXXXX)
if git rev-parse --verify HEAD >/dev/null 2>&1
then
against=HEAD
else
# Initial commit: diff against an empty tree object
against=4b825dc642cb6eb9a060e54bf8d69288fbee4904
fi
# Get a list of modified php files and run php -l against them.
for indexfile in `git diff-index --diff-filter=AM --name-only --cached $against | egrep '\.(php)'`
do
# Don't check empty files
if [ `git cat-file -s :0:$indexfile` -gt 0 ]
then
case $indexfile in
*.php )
# Check php syntax
git cat-file blob :0:$indexfile | php -l > $error_msg ;;
esac
if [ "$?" -ne 0 ]
then
echo -n "$indexfile: "
cat $error_msg
syntax_errors=`expr $syntax_errors + 1`
fi
fi
done
rm -f $error_msg
if [ "$syntax_errors" -ne 0 ]
then
echo "@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"
echo "@@ Error: syntax errors found, aborting commit. @@"
echo "@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"
exit 1
fi
Extending or modifying this script to suit your needs is pretty trivial. You can expand the egrep and case to include any other filetype you want to perform magic on, or you can run your unit tests after the loop, or send an e-mail, or make coffee, etc.
On Ruby & PHP
So I quit my job. That was a relatively big change for me, after spending 3 years sat on the same chair working with the same team. But I felt it was time for a change. The new job is quite a bit different from the old one. One rather obvious difference is the programming language .. I've gone back to my proverbial roots and am now churning out PHP on a daily basis. And because I'm such a programming nut, I'm working on some after-hours Ruby projects as well.
PHP and Ruby are both obviously very different from Java - and very different from each other. Sometimes in good ways, sometimes in bad ways. Syntax wise, PHP and Java are very similar. The dollar sign on my keyboard is definitely seeing a lot more action now, but other than that not many dramatic finger changes are required. PHP doesn't have have a bunch of things I like, like final method arguments, multit-hreading or a half decent collection of standard classes. What it does have is excellent documentation and easy & interesting meta-programming. That, and it's obviously much more tailored for the web than Java. For the first time in 3 years I *don't* actually need a whole armada of frameworks just to get something simple done. Still .. I miss my (Concurrent)HashMap, ArrayList, and most importantly my trusted BigDecimal.
And then there's Ruby .. Even after a couple of months of Ruby, I have very mixed feelings about it. The documentation sucks. Don't argue with me, it really does suck big fucking donkey balls. RDoc (especially online) is to JavaDoc what Spam is to nice and tasty Prosciutto. Then there's the lack of backwards compatibility (granted, Java may take this a bit too far, but still).
And then ... there's the syntax. This is where my feelings are mixed, rather than plain negative. There's too much choice. You can mix and match a bunch of styles, do..end, curly brackets, semicolons or no semicolons, method arguments with or without braces, and the list probably goes on. This leads to code that's hard to read (and thus hard to maintain), especially when different people stick to different styles. On the other hand, it also leads to nice syntactic sugar. Clever use of methods can make it look like you're defining your own keywords, which is very nice for creating your own DSLs. It's also rather nice to have Operator Overloading, and being able to treat everything like an object also has its benefits.
Still .. my feelings remain mixed. And in spite of everything, I feel like Java is still the only choice for Serious work. Not only because of the amazing documentation, the excellent standard library or even the massive community, but also for the amazing JVM, its security model and its thriving ecosystem.
Java ain't dead, folks.
Fosdem 2011
Of course I'll be there. I'm helping out with the Beer Event again. I'll see you there!
OutOfMemoryError while running Maven Surefire tests
Imagine you have a project which works perfectly fine and well. All tests pass, each and every time. Then one day you commit a couple of new classes with related tests. Of course you ran all tests before committing, and everything worked just fine. Then, a minute or so later, you get a mail from Hudson (or whatever you're using for CI) saying that there are test failures. "Maybe I forgot a file", I thought. Checked the test results on Hudson. About a dozen tests were failing, unrelated to anything I touched. Odd. OutOfMemoryErrors all over the place. Most odd. Hudson's tomcat has 1G, which should be plenty. Same with each build's MAVEN_OPTS.
Apparently, someone who wrote the Maven Surefire Plugin thought that it would be a GREAT idea to ignore things like MAVEN_OPTS and other memory settings. The plugin seems to start a new JVM instance to run the tests. Without any of the arguments you so carefully selected. No. Apparently you have to explicitly tell the Surefire plugin that maybe, just maybe, it would be a good idea to use the memory settings you already provided elsewhere.
Anyhoo, this fixed it:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.6</version>
<configuration>
<argLine>-Xmx512m</argLine>
</configuration>
</plugin>
DRY, you say? Not so much, eh.
Maven 3 resource filtering weirdness
Maven 3 is all nice and fast(er) and shiny, so I decided to upgrade a Maven 2 project to Maven 3. It (cl)aims to be backwards-compatible, so my consternation was pretty great when my build failed straight away. That's to say, my tests failed. For some reason, my resources were no longer being filtered. Yup, ${property.keys} weren't being replaced by values.
This struck me as being somewhat odd, because it worked fine with 2.2.1. A bit of debugging led me to the cause of the problem:
<!-- @Transactional can now be used as well -->
... apparently, the @ symbol is an escape character of sorts.
Considering that blurb on their website doesn't even qualify as English, I'm not sure if this is a feature or a bug. But whatever. Removing that comment fixed the problem. Whoever came up with that bright idea (especially in an age where @annotations are as rampant as the black plague in the 14th century) probably deserves a spanking.
Bored Java Dev looking for Open Source project
I've got a bit too much spare time on my hands and I'm having a hard time finding an interesting open source java project. My definition of interesting is pretty broad, but it generally includes "useful".
If you want my assistance, just give me a shout!