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max-identifier-blocks

Restrict identifier complexity to at most four casing blocks.

Targeted pattern scope​

This rule checks identifier names in:

  • declaration identifiers (Identifier.id), and
  • non-shorthand object property keys (Identifier.key where shorthand is false).

It counts naming "blocks" by splitting on case transitions and non-alphanumeric separators.

What this rule reports​

This rule reports identifiers that contain more than four casing blocks (for example, AaaBbbCccDddEee).

Why this rule exists​

Long compound identifiers are harder to read and often indicate mixed concerns in one symbol.

❌ Incorrect​

const AaaBbbCccDddEee = 1;
function aaaBbbCccDddEee() {}

const obj = {
 veryLongCompoundIdentifierName: 1,
};

✅ Correct​

const AaaBbbCccDdd = 1;
function aaaBbbCccDdd() {}

Behavior and migration notes​

The block limit is fixed at 4 in the current implementation.

This rule reports only and does not provide an autofix.

Options​

This rule has no options.

Additional examples​

const parse_http_response_body = true;
// underscore-separated segments are also counted as blocks

const parseHttpBody = true;
// ✅ shorter identifier

ESLint flat config example​

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

export default [
 {
  plugins: { "etc-misc": etcMisc },
  rules: {
   "etc-misc/max-identifier-blocks": "error",
  },
 },
];

When not to use it​

Disable this rule if your project allows long compound identifier names.

Package documentation​

Rule catalog ID: R021

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.