n/no-path-concat

When you glue a path together by hand, you hardcode the separator. On Windows, __dirname + "/data.json" gives C:\app/data.json, which isn't equal to the same path from path.join(). path.join() and path.resolve() use the platform's separator and clean up .. and doubled separators.

The rule reports __dirname or __filename followed by text that starts with / or \, or by path.sep.

Configure#

Off by default. To turn it on:

[lint.rules]
"n/no-path-concat" = "error" # or "warn"

Examples#

Reported:

const config = __dirname + "/config.json";
const cache = `${__dirname}/cache/${name}`;
const logs = __dirname + path.sep + "logs";

Not reported:

const path = require("path");

const config = path.join(__dirname, "config.json");
const cache = path.resolve(__dirname, "cache", name);

Adding something that isn't a new path segment is fine:

const sourceMap = __filename + ".map";