feat: add require-assert-message rule

[electrohyun]

Disclosure: I'm a participant of open source contribution program OSSCA

Important

This PR currently supports only node:assert and node:assert/strict; bare assert and assert/strict specifiers are not supported.
I would appreciate feedback on whether this scope is appropriate before merging.

To avoid false positives, the rule conservatively skips all calls through a CommonJS assertion binding if that binding is reassigned after initialization. This can also skip calls that appear before the reassignment. It does not currently exclude property mutations such as assert.ok = mock.

What is the purpose of this pull request?

This PR adds n/require-assert-message, a rule that requires messages for Node.js assert calls.

Without a message, assertion failures fall back to Node.js's default AssertionError message, which can make the reason for a failure harder to identify. The rule reports missing or obviously empty messages for assertion APIs whose message position can be determined statically.

What changes did you make? (Give an overview)

• Added n/require-assert-message.
  • Tracks node:assert, node:assert/strict, and the strict export from node:assert.
  • Checks assert(), assert.ok(), equality assertions, match(), doesNotMatch(), and partialDeepStrictEqual().
  • Reports a missing message, global undefined, a void expression, an empty string, and an empty template literal.
• Excluded throws, doesNotThrow, rejects, and doesNotReject because their optional error argument makes the message position ambiguous.
• Excluded ifError, which has no message parameter, and fail, which is commonly used to mark unreachable code.
• To avoid false positives, conservatively skips all calls through a CommonJS assertion binding if that binding is reassigned after initialization. This can also skip calls that appear before the reassignment.
• Added rule tests and documentation, and updated the generated rule list in the README.

Related Issues

refs #322

Is there anything you'd like reviewers to focus on?

1. Bare specifier scope

• The rule currently supports only node:assert and node:assert/strict. Should it also support bare assert and assert/strict specifiers to align with existing plugin rules?

2. Property mutation policy

• Reassigned bindings are excluded:

  let assert = require("node:assert");
  assert = mock;
  assert.ok(user); // Not reported.

• The current binding-reassignment policy is intentionally conservative and may also create false negatives for calls before the reassignment.

• However, property mutations are not currently excluded:

  const assert = require("node:assert");
  assert.ok = mock;
  assert.ok(user); // May still be reported.

• This is an uncommon case. Please let me know whether it should also be excluded, or whether limiting the rule to binding reassignment is the right scope.

[Copilot]

Pull request overview

Adds n/require-assert-message to enforce meaningful messages for supported Node.js assertion APIs.

Changes:

• Implements assertion reference tracking and message validation.
• Adds comprehensive rule tests and documentation.
• Registers the rule and updates the generated rule list.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
lib/rules/require-assert-message.js	Implements the new rule.
lib/all-rules.js	Registers the rule.
tests/lib/rules/require-assert-message.js	Adds rule test cases.
docs/rules/require-assert-message.md	Documents behavior and scope.
README.md	Adds the rule to the rule list.

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[electrohyun]

Applied the Copilot review feedback and renamed isEmptyString to isEmptyMessage since it now also checks for null.