JavaScript ES2026 operator

Design and repair JavaScript promises, async functions, async iterables, cancellation, timeouts, bounded concurrency, retries, and resource cleanup. Use when work races, hangs, leaks, retries incorrectly, or needs cancellation and concurrency limits.

Look up JavaScript commands, configuration, runtime patterns, and focused operations across modules, async control flow, dom and events, data modeling, performance and security. Use when the user wants a concise reference instead of a guided workflow.

Model JavaScript data with objects, arrays, maps, sets, iterables, immutability, cloning, equality, dates, numeric values, and JSON serialization. Use when choosing data structures, fixing mutation bugs, normalizing payloads, or preserving serialized contracts.

Operate browser DOM queries, element creation, event listeners, delegation, custom events, observers, focus, and lifecycle cleanup. Use when adding browser interaction, fixing duplicate handlers or stale nodes, or integrating with native DOM behavior.

Inspect the installed JavaScript runtime, package manager, module mode, project configuration, entry points, generated output, target environments, and checks without changing anything. Use before JavaScript work, when conventions are unknown, or when the user asks what is configured.

Connect JavaScript to build tools, tests, linting, formatting, CI, browser and server runtimes, package boundaries, and deployment artifacts while preserving ownership between layers. Use when JavaScript must cross another project subsystem or behave consistently from development through production.

Operate JavaScript modules across ESM and CommonJS, including imports, exports, package type, file extensions, dynamic loading, cycles, and browser delivery. Use when adding modules, fixing import failures, publishing exports, or migrating module format.

Measure and improve JavaScript runtime performance and security across hot paths, memory retention, parsing, dynamic code, prototype access, and untrusted input. Use when diagnosing slow or leaking code, reviewing injection risk, or hardening an input boundary.

Install and configure JavaScript from zero with a project-local toolchain, explicit runtime and module targets, source and output boundaries, baseline checks, and one verified example. Use when a project has no JavaScript setup or the user explicitly asks to initialize it.

Diagnose JavaScript failures involving parsing, types, modules, configuration, async behavior, runtime differences, generated output, tests, integrations, security, and performance without masking the original error. Use when JavaScript code fails a check, behaves differently across environments, or produces unexpected output.