SYNOPSIS

Bash programming does not read clearly inside a package.json script field. This program helps test environment variables and create conditional output.

EXAMPLE

package.json scripts likely want some context about their environment. In this example we want to add the --debug flag to the browserify program before we run it, but only if the NODE_ENV environment variable has not been set.

"scripts": {
  "build-js": "browserify $(test-env !NODE_ENV '--debug') browser/*.js > static/bundle.js"
}

USAGE

TESTING

If the variable exists, the second argument will be written to stdout. If the test is false, and a third variable is supplied it will be printed.

$test-env VARIABLE_NAME Yes

$test-env VARIABLE_NAME Yep Nope

If the variable does not exist, the second argument will be written to stdout. If the test is false, and a third variable is supplied it will be printed.

$test-env !USER "Yeah ok, sure"

$test-env !USER 1 2

COMPARING

The comparison operators are supported

• == (or eq) Equal
• != (or not) Not Equal
• gt Greater Than
• lt Less Than
• gte Greater Than or Equal To
• lte Less Than or Equal To

$test-env SHLVL == 2 Yep Nope
Yep

$test-env SHLVL gte 1 OK "NOT OK"
OK