# Modernizr's Feature detection approach
- Conformance testing (like WebKit layoutTests, Mozilla Mochitests, and W3C Test Suites) test the full range of functionality to make sure the browser handles all edge cases in the spec correctly
- Feature testing will run through behavior (like setting a value into localStorage and reading it out).
- Feature detection will lightly see if such a feature's API exists (
!!window.localStorage)
Many browsers get 80-100% coverage on conformance tests. Even robust implementations that most developers are content with may only get 80%.
Modernizr aims to write the fastest executable test that satisfies the 90% use case of what a developer wants to use a feature for.
So if a light sniff of !!window.localStorage will give the same result as a run through a conformance test, then we'll use it. (In localStorage's case, it doesn't and we have much more trickery involved.)
# Testing techniques
Testling is great for writing small tests that you can run on 30 different browsers in under a minute. Here are some testling feature tests we used to explore possible feature detects.
The Browserstack API is another great technique to try out some feature detects on a wide array of mobile phones. Look at node-browserstack for digging into that.
# Browsers we test in
# primary targets
- IE6 - IE10
- FF ESR, FF stable - FF Nightly
- Chrome stable - Chrome Canary
- Opera stable, Opera Next
- Safari 5.1, Webkit Nightly
- iOS4+
- Android 2.2+, Chrome on Android
# secondary targets
- Safari 4
- WebOS
- WP7
- BB6
- Opera Mobile
- Kindle Fire
# incomplete list of browsers that are lucky if they're compatible
- BB pre-6
- Opera Mini