message: Turn on alwaysStrict and noFallthroughCasesInSwitch (no errors)
diff: "moduleResolution": "node",
  "allowSyntheticDefaultImports": true,
  "noImplicitThis": true,
  + "alwaysStrict": true,
  + "strictNullChecks": true,
  + "noFallthroughCasesInSwitch": true,
  "noEmitOnError": false,
  "noEmit": true,
  - "strictNullChecks": true,
  "inlineSourceMap": true,
  "inlineSources": true,
  "baseUrl": ".",
  