shebang.md

Suggest correct usage of shebang (node/shebang)

When we make a CLI tool on Node.js, we add bin field to package.json, then we add a shebang the entry file. This rule suggests correct usage of shebang.

Rule Details

This rule looks up package.json file from each linitng target file. Starting from the directory of the target file, it goes up ancestor directories until found.

If package.json was not found, this rule does nothing.

This rule checks bin field of package.json, then if a target file matches one of bin files, it checks whether or not there is a correct shebang. Otherwise it checks whether or not there is not a shebang.

For files in bin field of package.json:

The following patterns are considered problems:

console.log("hello"); /*error This file needs shebang "#!/usr/bin/env node".*/

The following patterns are considered not problems:

#!/usr/bin/env node
console.log("hello");

For other files:

The following patterns are considered problems:

#!/usr/bin/env node   /*error This file needs no shebang.*/
console.log("hello");

The following patterns are considered not problems:

console.log("hello");

When Not To Use It

If you don't want to be notified about usage of shebang, then it's safe to disable this rule.