Running test on windows fails

[inspiraller]

OS: Windows 10
Steps:

1. git clone git@github.com:jsx-eslint/eslint-plugin-jsx-a11y.git
2. cd eslint-plugin-jsx-a11y
3. npm i
4. npm run test

output:

eslint-plugin-jsx-a11y@6.5.1 pretest
> npm run lint:fix && npm run flow


> eslint-plugin-jsx-a11y@6.5.1 lint:fix
> npm run lint -- --fix


> eslint-plugin-jsx-a11y@6.5.1 lint
> eslint . "--fix"


> eslint-plugin-jsx-a11y@6.5.1 flow
> if [ ! -e ./.flowconfig ]; then echo "Could not find .flowconfig"; else flow; test $? -eq 0 -o $? -eq 2; fi

! was unexpected at this time.

[inspiraller]

I have created a fork of this repo to fix this bug.
#856 (comment)

[inspiraller]

Note:
When running test - it runs flow - not jest
npm run test

I came across this github issue which describes the same problem:
zulip/zulip-mobile#3178

Which is odd when the package.json clear shows it should run jest:
"test": "npm run jest",
"jest": "jest --coverage tests/*",