Caching

Description:

We want to speed up our builds and we heard about this concept of "caching". We need to start storing a cache of our package.json so that it can be restored in subsequent builds.

In addition we need to know what to do if we need to force a new save of the cache.

Goals:

• Uncomment out the save_cache and restore_cache steps
• Update the key of each of those to point at the proper file
• Push up a commit where you find it successfully saves the cache (should see something like this on the step):

Creating cache archive...
Uploading cache archive...
Stored Cache to yarn-packages-v1-qwa_N++0aXeaXlpPu1TzrRMKJU1V7n3NYN+0BxBVg20=
  * /home/circleci/.cache/yarn

• Push another commit and confirm the cache is restored/used (should see something like this):

Found a cache from build 44 at yarn-packages-v1-qwa_N++0aXeaXlpPu1TzrRMKJU1V7n3NYN+0BxBVg20=
Size: 160 B
Cached paths:
  * /home/circleci/.cache/yarn

Downloading cache archive...
Validating cache...

Unarchiving cache...

• Finally make the neccesary edits to the config to 'bust' or 'clear' the cache so it doesn't use the existing saved cache and instead stores a new one.

Help:

Spoiler warning

• https://circleci.com/docs/2.0/caching/
• https://circleci.com/docs/2.0/yarn/#caching
• https://circleci.com/docs/2.0/caching/#clearing-cache