feat(keycodes): add utilities for checking modifier keys

[crisbeto]

Based off of the conversation in #13790, these changes add some utilities for dealing with modifier keys on keyboard events.

[crisbeto]

@devversion I'm not too sure how the tests should be set up with Bazel since this isn't an NgModule.

[devversion]

@crisbeto Have a look in the coercion entry-point. It uses the ts_library and jasmine_node_test.

[jelbourn]

This one is definitely a feat for the next minor

[crisbeto]

@devversion by the looks of it, the jasmine_node_test isn't running in a browser environment.

[devversion]

@crisbeto Ah I didn't realize you wanted to run them in the browser. You should be able to use ts_web_test_suite (you can see an example in tools/defaults.bzl).

Just be aware that the one in defaults.bzl loads some Angular things you won't need if you just run standard tests on the browser.

[josephperrott]

LGTM

[ngbot]

Hi @crisbeto! This PR has merge conflicts due to recent upstream merges.
Please help to unblock it by resolving these conflicts. Thanks!

[crisbeto]

Sorted out the test issues with help from @devversion. @jelbourn@devversion can you take another look?

[devversion]

LGTM.

[jelbourn]

LGTM

[mmalerba]

should we use an enum for this?

[crisbeto]

We could, but I wanted to keep the consumption as short as possible. With the enum people would need another import and the call would look like hasModifierKeys(event, ModifierKey.altKey, ModifierKey.shiftKey) which gets a little long.

[jelbourn]

Strings also make sense here because they are the real properties on KeyboardEvent

[angular-automatic-lock-bot]

This issue has been automatically locked due to inactivity.
Please file a new issue if you are encountering a similar or related problem.

Read more about our automatic conversation locking policy.

_{This action has been performed automatically by a bot.}