CircleCI project setup (#138)

.circleci/config.yml

@@ -0,0 +1,53 @@
+version: 2.1
+orbs:
+  node: circleci/node@3.0.0
+
+executors:
+    node:
+      parameters:
+        image:
+          type: string
+          # First 10.x LTS release, but old Yarn
+          default: "10.14"
+      docker:
+        - image: circleci/node:<< parameters.image >>
+
+aliases:
+  install_node_modules: &install_node_modules
+    run:
+      name: Install node modules
+      command: yarn --frozen-lockfile
+  attach_to_bootstrap: &attach_to_bootstrap
+    attach_workspace:
+        at: ./
+
+jobs:
+  bootstrap:
+    executor: node
+    steps:
+      - checkout
+      - run: ./scripts/assert-changed-files.sh "packages/*|(e2e|integration)-tests/*|.circleci/*|yarn.lock"
+      - <<: *install_node_modules
+      - run: yarn bootstrap --concurrency=2
+        # Persist the workspace again with all packages already built
+      - persist_to_workspace:
+          root: ./
+          paths:
+            - "*"
+
+  unit_test:
+    executor: node
+    steps:
+      - checkout
+      - run: ./scripts/assert-changed-files.sh "packages"
+      - <<: *attach_to_bootstrap
+      - run:
+          command: node --max-old-space-size=2048 ./node_modules/.bin/jest -w 1
+
+workflows:
+  test_all:
+    jobs:
+      - bootstrap
+      - unit_test:
+          requires:
+            - bootstrap