Start adding support for lock files.

Start adding support for lock files.

Lock files can be parsed (from strings) with tests.

Committed: https://code.google.com/p/dart/source/detail?r=8362

[Bob Nystrom, 2012-06-05 23:58:29]

Nathan is out, so you're my pub code review "volunteer" for the day. :)

[Jennifer Messerly, 2012-06-06 00:23:52]

lgtm

https://chromiumcodereview.appspot.com/10542015/diff/1/utils/pub/lock_file.dart
File utils/pub/lock_file.dart (right):

https://chromiumcodereview.appspot.com/10542015/diff/1/utils/pub/lock_file.da...
utils/pub/lock_file.dart:68: if (name != id.name) {
How could this happen? It sounds like this means description got mismatched from
the name?

Might be worth giving more information in the exception message, if the message
is intended for end users, so they know what went wrong and how to fix it.

https://chromiumcodereview.appspot.com/10542015/diff/1/utils/tests/pub/pubspe...
File utils/tests/pub/pubspec_test.dart (right):

https://chromiumcodereview.appspot.com/10542015/diff/1/utils/tests/pub/pubspe...
utils/tests/pub/pubspec_test.dart:5: #library('pubspec_test');
Why not empty string? Random characters? Shakespeare sonnet?

kidding ;)

[Bob Nystrom, 2012-06-06 20:44:48]

Thanks!

https://chromiumcodereview.appspot.com/10542015/diff/1/utils/pub/lock_file.dart
File utils/pub/lock_file.dart (right):

https://chromiumcodereview.appspot.com/10542015/diff/1/utils/pub/lock_file.da...
utils/pub/lock_file.dart:68: if (name != id.name) {
On 2012/06/06 00:23:52, John Messerly wrote:
> How could this happen? It sounds like this means description got mismatched
from the name?

Exactly right. This shouldn't occur in practice, but it doesn't hurt to sanity
check it. The "description" is a source-specific string that the source
interprets to uniquely identify a package. For example, it will be a git URL if
the source is git. Given that, the source is also responsible for yielding a
nice short package name.

The lock file lists the packages by the short name and includes the description.
So this just sanity checks that those aren't out of sync.

> 
> Might be worth giving more information in the exception message, if the
message
> is intended for end users, so they know what went wrong and how to fix it.

This shouldn't happen much in practice. The lock file will be generated
automatically by pub (it's the result of solving the version constraints) and
then parsed back in by it. But users could always hand-edit it or do something
weird, so it's good to validate it.

If we find that people hit this error, I'll definitely do better
error-reporting. I consider error-reporting a core piece of pub's UI, given that
it's a command line app that heavily works with files users hand-edit.

https://chromiumcodereview.appspot.com/10542015/diff/1/utils/tests/pub/pubspe...
File utils/tests/pub/pubspec_test.dart (right):

https://chromiumcodereview.appspot.com/10542015/diff/1/utils/tests/pub/pubspe...
utils/tests/pub/pubspec_test.dart:5: #library('pubspec_test');
On 2012/06/06 00:23:52, John Messerly wrote:
> Why not empty string? Random characters? Shakespeare sonnet?
> 
> kidding ;)

Changed to:

#library("""Let those who are in favour with their stars
Of public honour and proud titles boast,
Whilst I, whom fortune of such triumph bars
Unlook'd for joy in that I honour most.
Great princes' favourites their fair leaves spread
But as the marigold at the sun's eye,
And in themselves their pride lies buried,
For at a frown they in their glory die.
The painful warrior famoused for fight,
After a thousand victories once foiled,
Is from the book of honour razed quite,
And all the rest forgot for which he toiled:
Then happy I, that love and am beloved,
Where I may not remove nor be removed.""");