promise/no-nesting Style

🚧 An auto-fix is still under development.

Disallow nested then() or catch() statements.

Nesting promises makes code harder to read and understand.

Examples of incorrect code for this rule:

javascript

doThing().then(() => a.then());

javascript

doThing().then(function () {
  a.then();
});

javascript

doThing().then(() => {
  b.catch();
});

Examples of correct code for this rule:

javascript

doThing().then(() => 4);

javascript

doThing().then(function () {
  return 4;
});

javascript

doThing().catch(() => 4);

javascript

doThing()
  .then(() => Promise.resolve(1))
  .then(() => Promise.resolve(2));

This example is not a rule violation as unnesting here would result in a being undefined in the expression getC(a, b).

javascript

doThing().then((a) => getB(a).then((b) => getC(a, b)));

How to use

To enable this rule in the CLI or using the config file, you can use:

CLIConfig (.oxlintrc.json)

bash

oxlint --deny promise/no-nesting --promise-plugin

json

{
  "plugins": ["promise"],
  "rules": {
    "promise/no-nesting": "error"
  }
}