Project code review

Code review

Structured code review that checks changes for correctness, type safety, security, style, and maintainability. Produces actionable findings categorized by severity.

All underlying rules referenced below are defined in AGENTS.md.

Process

Read the diff or files under review, then evaluate each category below. Skip categories that do not apply to the language or change.

Correctness

• Logic errors, off-by-one, unhandled edge cases
• Missing null/undefined checks
• Race conditions in async code
• Incorrect use of APIs or library methods
• Broken error propagation (swallowed exceptions, silent catch blocks)

Off-by-one and boundary errors

// Bad -- flag as WARNING
const lastItem = items[items.length];

// Good
const lastItem = items.at(-1,);

// Bad -- flag as WARNING: skips the last element
for (let index = 0; index < items.length - 1; index++) { ... }

// Good
// Looping is unavoidable here because each item has side effects
for (const item of items) { ... }

Missing null/undefined checks

// Bad -- flag as BLOCKER
function getUser(id: string,): User {
  const user = users.find(candidate => candidate.id === id);
  return user; // may be undefined
}

// Good
function getUser(id: string,): User {
  return notNullishOrThrow(users.find(function matchesId(candidate,) {
    return candidate.id === id;
  },),);
}

Race conditions

// Bad -- flag as WARNING: shared mutable state with concurrent access
const cache: Map<string, Data> = new Map();

async function getData(key: string,): Promise<Data> {
  if (!cache.has(key,)) {
    const data = await fetchData(key,);
    cache.set(key, data,); // another call may have set it while awaiting
  }
  return notNullishOrThrow(cache.get(key,),);
}

Broken error propagation

// Bad -- flag as WARNING: swallowed exception
try {
  await saveRecord(record,);
}
catch {
  // silently ignored
}

// Good
try {
  await saveRecord(record,);
}
catch (error) {
  console.error('Failed to save record:', error,);
  throw new Error('Failed to save record', { cause: error, },);
}

Type safety (TypeScript)

• Explicit return types on all functions
• unknown over any; no bare Function type
• No non-null assertions (!); use assertion functions or narrowing
• Branded types for domain primitives where appropriate
• satisfies over as when validating shape without widening
• const generic parameters; readonly array parameters
• Proper discriminated unions; narrow typeof === 'symbol' before identity checks

Explicit return types

// Bad -- flag as WARNING
function parseConfig(raw: string,) {
  return JSON.parse(raw,);
}

// Good
function parseConfig(raw: string,): Config {
  return JSON.parse(raw,) as Config;
}

unknown over any

// Bad -- flag as WARNING
function processInput(data: any): void { ... }

// Bad -- flag as WARNING: bare Function type
function runCallback(callback: Function): void { ... }

// Good
function processInput(data: unknown): void { ... }

// Good
function runCallback(callback: () => void): void { ... }

Domain-specific types

// Bad -- flag as NIT: primitive type loses domain meaning
function getUser({ id }: { id: string }): User { ... }
function setPermissions({ level }: { level: number }): void { ... }

// Good -- branded type for opaque identifiers
type UserId = string & { readonly __brand: 'UserId' };
function getUser({ id }: { id: UserId }): User { ... }

// Good -- union type for small finite sets
type PermissionLevel = 1 | 2 | 3;
function setPermissions({ level }: { level: PermissionLevel }): void { ... }

// Good -- template literal type for structured strings
type SemVer = `${number}.${number}.${number}`;
function parseVersion({ version }: { version: SemVer }): VersionInfo { ... }

Explicit type annotations and satisfies

// Bad -- flag as WARNING: as widens the type
const config = { host: 'localhost', port: 8080, } as ServerConfig;

// Good -- explicit type annotation on the variable when possible
const config: ServerConfig = { host: 'localhost', port: 8080, };

// Good -- satisfies when direct annotation is not possible (e.g. exported configs)
export default { host: 'localhost', port: 8080, } satisfies ServerConfig;

Symbol union narrowing

Flag code that compares a value to a specific symbol and assumes the else branch is non-symbol:

// Anti-pattern -- flag as BLOCKER
if (out === NO_LITERAL) {
  // handle sentinel
}
else {
  // BUG: else may still be a symbol from the union
  use(out.parsed,);
}

// Correct pattern
if (typeof out === 'symbol') {
  if (out === NO_LITERAL) {
    // handle sentinel
  }
  else {
    throw new Error(`Unexpected symbol: ${String(out,)}`,);
  }
}
else {
  use(out.parsed,);
}

Generics

Flag missing const or readonly modifiers:

// Bad -- flag as WARNING
function processItems<T extends { id: string; },>(items: T[],): T[];

// Good
function processItems<const T extends { id: string; },>(
  items: readonly T[],
): readonly T[];

// Bad -- flag as WARNING
function myFn<const T,>(myArr: T[],): T[];

// Good
function myFn<const T,>(myArr: readonly T[],): T[];

Flag non-descriptive generic names:

// Bad -- flag as NIT
<T extends Record<string, unknown>>

// Good
<TUser extends Record<string, unknown>>

Function signatures

• Functions with 2+ parameters must use a single destructured object parameter (named params)
• No rest parameters (...args) in functions we control; accept an array parameter instead
• No const x = function() {} -- use a function declaration instead
• No calling functions before their declaration in source order
• Exempt: callbacks whose signature is dictated by an external API or library (e.g. .map(), .sort(), event handlers)

No variable function expressions

Flag function expressions assigned to variables:

// Bad -- flag as WARNING
const greet = function greet(name: string,): void {};
const greet = function(name: string,): void {};

// Good -- use a function declaration
function greet(name: string,): void {}

Named parameters

Flag any function declaration or named arrow function with 2+ positional parameters:

// Bad -- flag as WARNING
function clamp(value: number, min: number, max: number,): number {
  return Math.max(min, Math.min(max, value,),);
}

// Good
function clamp(
  { value, min, max, }: { value: number; min: number; max: number; },
): number {
  return Math.max(min, Math.min(max, value,),);
}

// Bad -- flag as WARNING
function fetchUser(id: string, signal: AbortSignal): Promise<User> { ... }

// Good
function fetchUser({ id, signal }: { id: string; signal: AbortSignal }): Promise<User> { ... }

Callbacks passed to external APIs are exempt because the caller dictates the signature:

// OK -- signature dictated by Array.prototype.map
const doubled = items.map(function doubleByIndex(item, index,) {
  return multiply({ value: item, by: index, },);
},);

// OK -- signature dictated by Array.prototype.sort
const sorted = items.sort(function byPriority(left, right,) {
  return left.priority - right.priority;
},);

No use before declaration

Flag function calls that appear before the function's declaration in source order. Hoisting makes this legal at runtime but breaks top-down readability:

// Bad -- flag as WARNING: b() called before its declaration
const a = b();

function b(): string {
  return 'hello';
}

// Good -- declaration before use
function b(): string {
  return 'hello';
}

const a = b();

Rest parameters

Flag rest parameters in functions we control:

// Bad -- flag as WARNING
function logMessages(...messages: readonly string[]): void { ... }

// Good
function logMessages({ messages }: { messages: readonly string[] }): void { ... }

Immutability and style

• const over let; no unnecessary mutation
• Justify or refactor: any deviation from the preferred pattern must have a comment explaining why refactoring to the preferred approach is not feasible; if no justification is given, flag it as WARNING
• Functional patterns (map/filter/reduce) over imperative loops
• for...of when iteration is unavoidable, never classic for loops
• No single-letter variables (except math formulas)
• Magic numbers/strings extracted to named constants (0, 1, 2, -1, -2 exempt); when a named constant's value is composed from exempt-range arithmetic (e.g. 1 / (2 * 2) for 1/4, (16 - 2 - 1) / 16 for 13/16), do not flag the expression as a readability issue
• Extract and name complex conditions

const over let

// Bad -- flag as WARNING
let baseUrl = 'https://api.example.com';

// Good
const baseUrl = 'https://api.example.com';

// Bad -- flag as WARNING: accumulator mutated via let
let total = 0;
for (const item of items)
  total += item.price;

// Good
const total = items.reduce(function addPrice(sum, item,) {
  return sum + item.price;
}, 0,);

Magic numbers and strings

// Bad -- flag as WARNING
if (retries > 3) { ... }
await wait(5000);

// Good
const maxRetries = 3;
const retryDelayMs = 5000;
if (retries > maxRetries) { ... }
await wait(retryDelayMs);

// OK -- exempt-range composition in a named constant; do NOT flag
const BORDER_RADIUS = 1 / (2 * 2);
const FONT_SIZE = (16 - 2 - 1) / 16;

for...of over classic for

// Bad -- flag as WARNING
for (let index = 0; index < items.length; index++)
  process(items[index],);

// Good (when functional patterns do not apply)
// Iteration is unavoidable because process() has side effects
for (const item of items)
  process(item,);

Functional over imperative

Flag imperative patterns when functional alternatives exist:

// Bad -- flag as WARNING
let results = [];
for (let i = 0; i < items.length; i++) {
  if (items[i].isActive)
    results.push(items[i].value * 2,);
}

// Good
const results = items
  .filter(function isActive(item,) {
    return item.isActive;
  },)
  .map(function doubleValue(item,) {
    return item.value * 2;
  },);

Object iteration

Flag for...in loops on objects:

// Bad -- flag as WARNING
for (const key in obj) {
  if (Object.prototype.hasOwnProperty.call(obj, key,))
    result[key] = process(obj[key],);
}

// Good
Object.entries(obj,).forEach(function applyProcess([key, value,],) {
  result[key] = process(value,);
},);

// Good (for transformations)
const result = Object.fromEntries(
  Object.entries(obj,).map(function processEntry([key, value,],) {
    return [key, process(value,),];
  },),
);

No switch statements

Flag all switch statements. Use if/else chains for branching or Record lookups for mapping a discriminant to a value.

switch adds break boilerplate, risks accidental fallthrough, and encourages large blocks. If/else works naturally with early returns and needs no special syntax. When the logic is a pure mapping from key to value, a Record is more declarative and type-safe.

// Bad -- flag as WARNING: switch statement
switch (toolName) {
  case 'Read': {
    return `Reading ${shortPath(filePath,)}`;
  }
  case 'Edit': {
    return `Editing ${shortPath(filePath,)}`;
  }
  case 'Bash': {
    return `Running ${shortCommand(command,)}`;
  }
  default: {
    return toolName;
  }
}

// Good -- if/else for branching with logic
if (toolName === 'Read')
  return `Reading ${shortPath(filePath,)}`;
else if (toolName === 'Edit')
  return `Editing ${shortPath(filePath,)}`;
else if (toolName === 'Bash')
  return `Running ${shortCommand(command,)}`;
else
  return toolName;

// Good -- Record lookup for pure mappings
const TOOL_LABELS: Record<string, (input: ToolInput,) => string> = {
  Read: function readLabel({ filePath, },) {
    return `Reading ${shortPath(filePath,)}`;
  },
  Edit: function editLabel({ filePath, },) {
    return `Editing ${shortPath(filePath,)}`;
  },
  Bash: function bashLabel({ command, },) {
    return `Running ${shortCommand(command,)}`;
  },
};

const labelFn = TOOL_LABELS[toolName];
return labelFn !== undefined ? labelFn(input,) : toolName;

Naming extracted concepts

Flag inline complex conditions:

// Bad -- flag as NIT
if (status === 'pending' && retries < maxRetries && !isTimeout) {
  // retry logic
}

// Good
function canRetry(): boolean {
  return status === 'pending' && retries < maxRetries && !isTimeout;
}

if (canRetry()) {
  // retry logic
}

Single-letter variables

// Bad -- flag as WARNING
for (let i = 0; i < items.length; i++)

// Good
for (let itemIndex = 0; itemIndex < items.length; itemIndex++)
items.forEach(function processItem(item, itemIndex) { ... })

Security

• No hardcoded secrets, API keys, or credentials
• No unsanitized user input in SQL, shell commands, or HTML
• No overly permissive CORS, file permissions, or network exposure
• Secrets not logged, even at debug level

Hardcoded secrets

// Bad -- flag as BLOCKER
const apiKey = 'sk-live-abc123def456';

// Good
const apiKey = notNullishOrThrow(process.env['API_KEY'],);

Unsanitized user input

// Bad -- flag as BLOCKER: shell injection
const output = execSync(`grep ${userQuery} /var/log/app.log`,);

// Good
const output = execSync('grep', [userQuery, '/var/log/app.log',],);

// Bad -- flag as BLOCKER: SQL injection
const rows = db.query(`SELECT * FROM users WHERE name = '${name}'`,);

// Good
const rows = db.query('SELECT * FROM users WHERE name = ?', [name,],);

Secrets in logs

// Bad -- flag as BLOCKER
console.log('Authenticating with token:', token,);

// Good
const tokenPrefixLength = 4;
console.log('Authenticating with token:',
  token.slice(0, tokenPrefixLength,) + '...',);

Naming and readability

• Semantic, descriptive names for variables, functions, types
• Comments explain WHY, not WHAT
• TSDoc on all declarations (functions, types, constants, classes -- including locals inside function bodies) with @param, @returns, @example; do not skip declarations that seem "obvious from context"
• @throws only on functions that actually throw; do not add @throws to functions that never throw
• Comments on their own line above code, never inline after code
• No narrative or promotional language in docs
• Region markers for substantial code blocks; flag missing markers as WARNING for substantial blocks and NIT for smaller ones

Comments inside template literals

Embed comments inside template literals using the ${''} trick. Do not use target-language comments (XML, HTML, etc.) or move the comment outside the template.

Reasons:

• Target-language comments require context switching between JS and the target language
• Editors cannot properly highlight target-language comments inside JS template literals
• Target-language comment syntax is easy to get wrong or forget across different languages

// Bad -- flag as NIT: target-language comment
const xml = `
  <os><type arch='x86_64'>hvm</type></os>
  <!-- Guest CPU requires AVX -->
  <cpu mode='host-passthrough'/>
`;

// Bad -- flag as NIT: comment disconnected from the line it explains
// Guest CPU requires AVX
const xml = `
  <os><type arch='x86_64'>hvm</type></os>
  <cpu mode='host-passthrough'/>
`;

// Good
const xml = `
  <os><type arch='x86_64'>hvm</type></os>
  ${
  // Guest CPU requires AVX
  ''}
  <cpu mode='host-passthrough'/>
`;

TSDoc quality

Flag WHY-less comments:

// Bad -- flag as NIT
/** Line counter starting at 1 */

// Good
/** Mutable counter needed to track newlines encountered while scanning */

Flag TSDoc on non-declarations:

// Bad -- flag as WARNING: TSDoc on a statement
/** Increment the counter */
counter++;

// Good
// Increment the counter to account for the trailing newline
counter++;

Escaping block comment terminators

Flag unescaped */ inside TSDoc blocks:

// Bad -- flag as BLOCKER: premature comment termination
/**
 * Returns a string like "/* comment */"
 */

// Good
/**
 * Returns a string like "/* comment *\\/"
 */

Async patterns

• async/await over raw promises or callbacks
• No .then(), .catch(), .finally() -- use async/await with try/catch or let errors propagate naturally by throwing
• Promise.all for independent concurrent operations
• Promise.allSettled when partial failure is acceptable
• No await in loops without justification and eslint-disable comment
• AbortController for cancellable operations
• Streams and subprocesses properly consumed or cleaned up

No .then()/.catch()/.finally()

// Bad -- flag as WARNING
function loadConfig(): Promise<Config> {
  return readFile('config.json', 'utf8',)
    .then(raw => JSON.parse(raw,) as Config)
    .catch(error => {
      console.error('Failed:', error,);
      throw error;
    },);
}

// Good
async function loadConfig(): Promise<Config> {
  const raw = await readFile('config.json', 'utf8',);
  return JSON.parse(raw,) as Config;
}

No await in loops

// Bad -- flag as WARNING: sequential when concurrency is possible
for (const url of urls) {
  const response = await fetch(url,);
  results.push(await response.json(),);
}

// Good
async function fetchJson(url: string,): Promise<unknown> {
  const response = await fetch(url,);
  return response.json();
}

const results = await Promise.all(urls.map(fetchJson,),);

Manual promise creation

Flag explicit new Promise when utilities exist:

// Bad -- flag as WARNING
function delay(ms,) {
  return new Promise(function resolveAfterDelay(resolve,) {
    setTimeout(resolve, ms,);
  },);
}

// Good
import { wait, } from '@monochromatic-dev/module-es';
// Use wait(ms) directly

Imports and modules

• Grouped: builtins, external deps, workspace packages, relative, type-only
• Named imports over default imports
• import type for type-only imports
• File extensions in relative imports when required by config
• No circular dependencies

Import grouping and style

// Bad -- flag as WARNING: ungrouped, missing extension, default import, missing import type
import { readFile, } from 'node:fs/promises';
import { z, } from 'zod';
import config from './config';
import { Config, } from './types';

// Good
import { readFile, } from 'node:fs/promises';

import { z, } from 'zod';

import { parseConfig, } from '@monochromatic-dev/module-es';

import { loadSettings, } from './config.ts';

import type { Config, } from './types.ts';

Error handling

• Prefer letting errors propagate by throwing
• No try...finally -- use using/await using with Symbol.dispose/Symbol.asyncDispose for cleanup
• Custom error classes extending Error for domain errors
• No process.exit(); throw instead
• Multi-line error messages use outdent from @cspotcode/outdent
• @throws in TSDoc only for functions that actually throw; flag @throws on non-throwing functions as NIT
• notNullishOrThrow instead of non-null assertion (!)
• Every catch block must log the error with console.error()

using over try...finally

// Bad -- flag as WARNING
const handle = openResource();
try {
  await process(handle,);
}
finally {
  handle.close();
}

// Good
await using handle = openResource();
await process(handle,);

No process.exit()

// Bad -- flag as WARNING
if (!isValid) {
  console.error('Invalid input',);
  process.exit(1,);
}

// Good
if (!isValid)
  throw new Error('Invalid input',);

outdent for multi-line error messages

// Bad -- flag as NIT
throw new Error(
  'Failed to process record.\n'
    + `Expected type: ${expectedType}\n`
    + `Received type: ${receivedType}`,
);

// Good
import { outdent, } from '@cspotcode/outdent';

throw new Error(outdent`
  Failed to process record.
  Expected type: ${expectedType}
  Received type: ${receivedType}
`,);

Custom error classes

class ValidationError extends Error {
  constructor(
    message: string,
    public readonly field: string,
  ) {
    super(message,);
    this.name = 'ValidationError';
  }
}

Type guards

function isString(value: unknown,): value is string {
  return typeof value === 'string';
}

Assertion functions

function assertIsString(value: unknown,): asserts value is string {
  if (typeof value !== 'string')
    throw new TypeError('Expected string',);
}

notNullishOrThrow over non-null assertion

// Bad -- flag as BLOCKER
const value = possiblyUndefined!;

// Good
import { notNullishOrThrow, } from '@monochromatic-dev/module-es';
const value = notNullishOrThrow(possiblyUndefined,);

Silent error handling

Flag empty catch blocks without logging:

// Bad -- flag as WARNING
catch (error) { }

// Good -- fatal error
catch (error) {
   throw new Error('Failed to get index stats', { cause: error });
}

// Good - expected error that shouldn't interrupt program operation.
catch (error) {
   console.error('Failed to get index stats:', error);
}

Flag silently discarded unexpected states:

// Bad -- flag as BLOCKER
if (!(event instanceof CustomEvent))
  return;

// Good
if (!(event instanceof CustomEvent))
  throw new TypeError('Expected CustomEvent',);

Markdown quality

• No tables in markdown files -- use nested headings or lists instead
• Flag any existing tables in changed markdown files as WARNING with a suggestion to convert

Tables to lists

<!-- Bad -- flag as WARNING -->

| Name | Type   | Default   |
| ---- | ------ | --------- |
| host | string | localhost |
| port | number | 8080      |

<!-- Good -->

- host -- `string`, default `localhost`
- port -- `number`, default `8080`

Testing gaps

• New logic paths missing corresponding test cases
• Edge cases not covered (empty input, boundary values, error paths)
• Mocking that hides real integration issues
• Flaky patterns (timing dependencies, shared mutable state)

Commit messages

When reviewing PRs or multi-commit bundles, also review commit messages.

Format

Conventional Commits: <type>(<scope>): <subject> with optional body and footer. Types: feat, fix, docs, style, refactor, perf, test, build, ci, chore, revert. Scope: package name or * for multi-package changes.

Single type and scope

feat(module-es): add a

Description of a

Multiple types and/or scopes

feat(module-es): enhance error handling utilities

error.assert.throw: add assertion-based error throwing
- Implement conditional error throwing based on assertions
- Include TypeScript type narrowing support

error.throw: add unified error throwing utility
- Implement consistent error creation
- Provide better stack traces
- Include custom error types

test(module-es): achieve 100% coverage for error utilities
- Add comprehensive test cases
- Use parameterized tests for edge cases
- Ensure proper type inference testing

Rules

• Group related changes by type (feat, fix, test, etc.)
• Do not mix different types in the same scope section
• Be specific about what changed, not just which files
• Focus on "what" and "why"
• Flag partial commit messages (describing only some changes) as WARNING

CSS quality

When changes include CSS, check:

• Native platform features over JS reimplementations (<dialog>, Popover API, CSS nesting)
• rem for all sizing; calc() for derivation; no px except device-pixel contexts
• Logical properties everywhere (no physical left/right/top/bottom)
• No shorthand properties that combine unrelated axes or sub-properties; single-axis/single-concept shorthands are fine (padding-inline, margin-block, border-radius, inset, gap)
• Colors via CSS custom properties; no var() fallbacks (exception: user-configurable)
• No !important
• :focus-visible on interactive elements; 48px minimum touch targets
• Shallow native nesting (3 levels max)
• Data attributes for state/variant styling, not BEM modifiers

Logical properties

/* Bad -- flag as WARNING: physical properties */
margin-left: 1rem;
padding-top: 0.5rem;
text-align: left;
top: 0;
right: 0;

/* Good */
margin-inline-start: 1rem;
padding-block-start: 0.5rem;
text-align: start;
inset-block-start: 0;
inset-inline-end: 0;

rem sizing

/* Bad -- flag as WARNING */
font-size: 14px;
padding-block: 8px;
border-radius: 4px;

/* Good */
font-size: calc(14 / 16 * 1rem);
padding-block: calc(8 / 16 * 1rem);
border-radius: calc(4 / 16 * 1rem);

:focus-visible and touch targets

/* Bad -- flag as WARNING: :focus instead of :focus-visible */
button:focus {
  outline-color: var(--focus-ring);
}

/* Bad -- flag as WARNING: touch target too small */
button {
  min-inline-size: 2rem;
  min-block-size: 2rem;
}

/* Good */
button {
  min-inline-size: 3rem; /* 48px equivalent */
  min-block-size: 3rem;

  &:focus-visible {
    outline-color: var(--focus-ring);
  }
}

Shallow nesting

/* Bad -- flag as WARNING: 4+ levels of nesting */
.card {
  & .header {
    & .title {
      & span {
        color: var(--accent-fg);
      }
    }
  }
}

/* Good -- max 3 levels */
.card {
  .title {
    & span {
      color: var(--accent-fg);
    }
  }
}

Shorthand properties

/* Bad -- flag as WARNING: multi-axis/multi-concept shorthands */
border: 1px solid #111;
padding: 0.5rem 1rem;
margin: 0 auto;
background: #fff url(...) no-repeat center;

/* Good -- longhand for multi-concept properties */
border-width: calc(1 / 16 * 1rem);
border-style: solid;
border-color: var(--gray-fg);

/* Good -- single-axis/single-concept shorthands are fine */
padding-block: 0.5rem;
padding-inline: 1rem;
margin-block: 0;
margin-inline: auto;
border-radius: 0.25rem;
inset: 0;
gap: 1rem;

Color tokens

/* Bad -- flag as WARNING */
color: #111;
border-color: #a00;

/* Good */
color: var(--gray-fg);
border-color: var(--error-fg);

State styling

<!-- Bad -- flag as NIT -->
<span class="pill pill--loading">

<!-- Good -->
<span class="pill" data-loading>

/* Bad */
.pill--loading {
  opacity: 0.5;
}

/* Good */
.pill {
  &[data-loading] {
    opacity: 0.5;
  }
}

Logging

• All loggers must use the tagged wrapper; no raw console.* or untagged logger instances
• Tags at every function/module boundary using myFn.name or subsystem name
• Composed tags for nested calls -- pass tagged({ tag, l }) down the call chain
• No manual tag prefixes in message strings

Untagged logger

// Bad -- flag as WARNING: untagged logger
export const l: Logger = $;

// Good
export const l: Logger = tagged({ tag: 'rss', },);

Manual tag in message string

// Bad -- flag as WARNING: manual tag prefix
l.info('[cycle] capture complete',);

// Good
const l = tagged({ tag: 'cycle', l: parentLogger, },);
l.info('capture complete',);

Shallow tagging

// Bad -- flag as NIT: logger not re-tagged for sub-function
function processItem({ item, l, }: { item: Item; l: Logger; },): void {
  l.info('processing',);
  transformItem({ item, l, },);
}

// Good -- deep tagging
function processItem(
  { item, l: parentLogger, }: { item: Item; l: Logger; },
): void {
  const l = tagged({ tag: processItem.name, l: parentLogger, },);
  l.info('processing',);
  transformItem({ item, l, },);
}

Script conventions

• No bash/shell scripts -- TypeScript only, executed with Node
• Top-level code, no main() wrapper; top-level await for async
• No process.exit() -- throw errors instead

No main() wrapper

// Bad -- flag as WARNING
async function main(): Promise<void> {
  const data = await loadData();
  console.log(data,);
}

main();

// Good
const data = await loadData();
console.log(data,);

Region markers

Flag missing //region///endregion markers on substantial code blocks:

//region User Authentication Logic -- Handles user login, registration, and session management

function loginUser(credentials: UserCredentials,): UserSession {
  return {} as UserSession;
}

function registerUser(details: UserDetails,): UserProfile {
  return {} as UserProfile;
}

//endregion User Authentication Logic

Output format

Summary: <one-line description of the change and overall assessment>

Findings:

BLOCKER:
- <file:line> <description and suggested action>

WARNING:
- <file:line> <description and suggested action>

NIT:
- <file:line> <description and suggested action>

NON-ACTIONABLE:
- <file:line> <description and best-effort ideas>

Omit empty severity sections. If no issues found, write "No issues found" under Findings.

Every item in BLOCKER, WARNING, and NIT must include a concrete suggested action. If you spot a real problem but cannot determine a specific fix, place it under NON-ACTIONABLE with best-effort ideas -- still report it, just be honest about uncertainty.