error starting create-react-app uv_cwd not found

I can NOT get create-react-app to run tests!

npx create-react-app testing
cd testing
npm start   <--- compiles successfully, opens in browser
(new tab)  npm test 

ERROR:

path.js:1167
          cwd = process.cwd();
                        ^

Error: ENOENT: no such file or directory, uv_cwd
    at Object.resolve (path.js:1167:25)
    at Function.Module._resolveLookupPaths (module.js:424:17)
    at Function.Module._resolveFilename (module.js:541:20)
    at Function.Module._load (module.js:474:25)
    at Module.require (module.js:596:17)
    at require (internal/module.js:11:18)
    at /usr/lib/node_modules/npm/bin/npm-cli.js:19:21
    at Object.<anonymous> (/usr/lib/node_modules/npm/bin/npm-cli.js:92:3)
    at Module._compile (module.js:652:30)
    at Object.Module._extensions..js (module.js:663:10)

I've tried:

1. upgrading node -- now am using 10.15.3
2. updated npm
3. deleting node_modules folder and reinstalling (npm i)

Help!