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typescript/prefer-array-type-alias

Prefer reusable alias names for array and tuple type aliases.

Targeted pattern scope​

This rule targets type alias identifiers when the alias annotation is:

  • TSArrayType (T[]), or
  • TSTupleType ([A, B]).

The alias name must match a PascalCase pattern ending in Array or s.

What this rule reports​

This rule reports array/tuple type aliases that do not follow preferred reusable alias naming.

Why this rule exists​

Collection-shaped aliases become easier to recognize and search when naming is consistent.

❌ Incorrect​

type Item = string[];

✅ Correct​

type Items = string[];

Behavior and migration notes​

This rule reports only and does not provide an autofix.

Migration is typically renaming the alias and updating references.

Options​

This rule has no options.

Additional examples​

type Pair = [string, string];
// ❌ reported

type Pairs = [string, string];
// ✅ valid

ESLint flat config example​

import etcMisc from "eslint-plugin-etc-misc";

export default [
 {
  plugins: { "etc-misc": etcMisc },
  rules: {
   "etc-misc/typescript/prefer-array-type-alias": "error",
  },
 },
];

When not to use it​

Disable this rule if your project does not standardize alias naming for array and tuple types.

Package documentation​

Rule catalog ID: R103

Further reading​

Adoption resources​

  • Start at warning level in CI, then move to error after cleanup.
  • Use focused codemods/autofix batches per package or directory.