ERROR in Module build failed (from ./node_modules/sass-loader/dist/cjs.js): SassError: Undefined mixin. angular cli code example

Example 1: Firebase deploy error - Cannot find module 'firebase'

Figured out the solution. I hadn't installed the firebase module in the functions folder but had included it in the parent folder of functions. I went into functions and ran npm install --save firebase and the deploy was successful.

Example 2: TS2307: Cannot find module './archive.svg' jest react

"jest": {
  "setupTestFrameworkScriptFile": "<rootDir>/jest.setup.js",
  "testPathIgnorePatterns": [
    "<rootDir>/.next/",
    "<rootDir>/node_modules/"
  ],
  "transform": {
    "\\.(gql|graphql)$": "jest-transform-graphql",
    ".*": "babel-jest",
    "^.+\\.js?$": "babel-jest"
  },
  "moduleFileExtensions": [
    "js",
    "json",
    "ts",
    "tsx"
  ],
  "modulePaths": [
    "<rootDir>/components/",
    "<rootDir>/pages/",
    "<rootDir>/shared/"
  ]
}