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no-try

Disallow try/catch/finally.

Targeted pattern scope​

This rule targets TryStatement nodes.

What this rule reports​

  • Any try { ... } catch { ... } or try/finally pattern

Why this rule exists​

This encourages explicit, value-oriented control flow over exception-based branching.

❌ Incorrect​

try {
  run();
} catch {
  recover();
}

✅ Correct​

const result = runSafely();
if (!result.ok) {
  return recover(result.error);
}

Additional examples​

// ❌ try/catch around JSON parsing
let payload;
try {
  payload = JSON.parse(raw);
} catch {
  return { ok: false, error: "Invalid JSON" };
}

// ✅ Dedicated safe parser that returns a result
const parseJson = (text: string) => {
  const parsed = safeJsonParse(text);
  return parsed.success
    ? { ok: true, value: parsed.value }
    : { ok: false, error: "Invalid JSON" };
};

return parseJson(raw);

ESLint flat config example​

import immutable from "eslint-plugin-immutable-2";

export default [
  {
    files: ["**/*.{js,mjs,cjs,ts,mts,cts,tsx}"],
    plugins: { immutable },
    rules: {
      "immutable/no-try": "error",
    },
  },
];

When not to use it​

try/finally remains valuable for resource cleanup (file handles, locks, tracing spans). If your runtime boundary needs exception handling for interoperability, keep the rule off in those adapters while preserving it in pure domain code.

Rule catalog ID: R912

Further reading​