Search URL

[wojtekmach]

Currently our homepage, https://diff.hex.pm, allows to search for packages but the URL never changes. Let's change that.
While at it, let's also support landing on /?package=...&to=... per #75.

[sigu]

Not sure how to raise feature requests so I am having this in here since its somehow related to having a search URL

1. Can we be able to choose the package versions diff while already on the diff page? This will be helpful to help us quickly find diffs on packages when we jump from hex.pm which only gives us the previous version with the current diff.

1. Can we have it such that by default we get the diff of the last two releases without necessarily specifying the diff versions. Have a look at the screenshot below

Both requests above will make it possible to quickly get diff by directly entering the package names on the URL and even create a custom quick search