tests,ci: replace yarn ci with npm ci, use typescript to run tests (#1875)

* deps: install dev-deps for ts, tests and friends

* tests: replace test.js with test.ts and fp

* change compat tests

* ci: replace tests to use npm as per usual

Author: waynevanson

.circleci/config.yml

@@ -8,8 +8,8 @@ jobs:
 
       - restore_cache:
           keys:
-          - v1-dependencies-{{ checksum "package.json" }}
-          - v1-dependencies-
+            - v1-dependencies-{{ checksum "package.json" }}
+            - v1-dependencies-
 
       - run: npm install
 

.prettierrc

@@ -0,0 +1,4 @@
+{
+  "tabWidth": 2,
+  "useTabs": false
+}