npm run test just hangs on jest w/o any feedback about typescript HOT 15 CLOSED

$ tsc --noEmit -p . && jest --no-cache
hello-world.test.ts(11,12): error TS2554: Expected 0 arguments, but got 1.
hello-world.test.ts(15,12): error TS2554: Expected 0 arguments, but got 1.
error An unexpected error occurred: "Command failed.
Exit code: 1
Command: sh
Arguments: -c tsc --noEmit -p . && jest --no-cache
Directory: /Users/matty/exercism/typescript/hello-world
Output:
".
info If you think this is a bug, please open a bug report with the information provided in "/Users/matty/exercism/typescript/hello-world/yarn-error.log".
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

Arguments: 
  /Users/matty/.nvm/versions/node/v8.10.0/bin/node /Users/matty/.nvm/versions/node/v8.10.0/bin/yarn test

PATH: 
  /Users/matty/.nvm/versions/node/v8.10.0/bin:/usr/local/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin

Yarn version: 
  1.5.1

Node version: 
  8.10.0

Platform: 
  darwin x64
  
Trace: 
  Error: Command failed.
  Exit code: 1
  Command: sh
  Arguments: -c tsc --noEmit -p . && jest --no-cache
  Directory: /Users/matty/exercism/typescript/hello-world
  Output:
  
      at ProcessTermError.MessageError (/Users/matty/.nvm/versions/node/v8.10.0/lib/node_modules/yarn/lib/cli.js:186:110)
      at new ProcessTermError (/Users/matty/.nvm/versions/node/v8.10.0/lib/node_modules/yarn/lib/cli.js:226:113)
      at ChildProcess.<anonymous> (/Users/matty/.nvm/versions/node/v8.10.0/lib/node_modules/yarn/lib/cli.js:30281:17)
      at emitTwo (events.js:126:13)
      at ChildProcess.emit (events.js:214:7)
      at maybeClose (internal/child_process.js:925:16)
      at Process.ChildProcess._handle.onexit (internal/child_process.js:209:5)

class HelloWorld {
    static hello( name = 'World' ) {
        return `Hello ${name}!`
    }
}

export default HelloWorld

import HelloWorld from "./hello-world"

describe('Hello World', () => {

  it('says hello world with no name', () => {
    expect(HelloWorld.hello()).toEqual('Hello, World!')
  })

  xit('says hello to bob', () => {
    expect(HelloWorld.hello('Bob')).toEqual('Hello, Bob!')
  })

  xit('says hello to sally', () => {
    expect(HelloWorld.hello('Sally')).toEqual('Hello, Sally!')
  })
})

$ yarn test
yarn run v1.5.1
$ tsc --noEmit -p . && jest --no-cache

rm -rf ~/exercism/typescript # your exercism directory
npm uninstall -g typescript && npm uninstall -g yarn # if originally installed via npm
rm -rf ~/node_modules/ # remove node modules
brew install typescript yarn
exercism fetch typescript
cd ~/exercism/typescript/hello_world/ # or wherever exercism places the directory

matty@laptop: ~/exercism/typescript/hello-world
$ yarn install && yarn test
yarn install v1.5.1
[1/4] 🔍  Resolving packages...
[2/4] 🚚  Fetching packages...
[3/4] 🔗  Linking dependencies...
[4/4] 📃  Building fresh packages...
✨  Done in 3.41s.
yarn run v1.5.1

$ tsc --noEmit -p . && jest --no-cache
hello-world.test.ts(11,12): error TS2554: Expected 0 arguments, but got 1.
hello-world.test.ts(15,12): error TS2554: Expected 0 arguments, but got 1.
error An unexpected error occurred: "Command failed.
Exit code: 1
Command: sh
Arguments: -c tsc --noEmit -p . && jest --no-cache
Directory: /Users/matty/exercism/typescript/hello-world
Output:
".
info If you think this is a bug, please open a bug report with the information provided in "/Users/matty/exercism/typescript/hello-world/yarn-error.log".
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.
matty@laptop: ~/exercism/typescript/hello-world

class HelloWorld {
    static hello( name = 'World' ) {
        return `Hello ${name}!`
    }
}

export default HelloWorld

$ yarn install && yarn test
yarn install v1.5.1
[1/4] 🔍  Resolving packages...
success Already up-to-date.
✨  Done in 0.32s.
yarn run v1.5.1
$ tsc --noEmit -p . && jest --no-cache

➜ tsc -v
Version 2.7.2
➜ yarn -v
1.5.1
➜ node -v
v9.8.0
➜ npm -v
5.6.0

class HelloWorld {
    static hello( name = 'World' ) {
        return `Hello ${name}!`
    }
}

export default HelloWorld