refactor: use npm instead of yarn

Author: codepunkt

.github/workflows/test.yml

@@ -22,7 +22,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        node-version: [12.x, 14.x]
+        node-version: [14.x, 16.x]
     steps:
     - uses: actions/checkout@v2
     - name: Use Node.js ${{ matrix.node-version }}
@@ -31,14 +31,14 @@ jobs:
         node-version: ${{ matrix.node-version }}
     - name: Install dependencies
       run: |
-        yarn install --frozen-lockfile
+        npm ci
         cd test/e2e/example
-        yarn install --frozen-lockfile
+        npm ci
       env:
         CI: true
     - name: Run tests and generate coverage information
       run: |
-        yarn run test:ci
+        npm run test:ci
       env:
         CI: true
     - name: Upload coverage to Codecov

.npmrc

@@ -0,0 +1 @@
+legacy-peer-deps=true

jest.config.js

@@ -9,6 +9,11 @@ module.exports = {
     '!src/index.ts',
     '!src/defaultOptions.ts',
   ],
+  globals:{
+    'ts-jest': {
+      diagnostics: false
+    },
+  },
   watchPlugins: [
     require.resolve('jest-watch-typeahead/filename'),
     require.resolve('jest-watch-typeahead/testname'),