Roadmap

Status: v0.2.4 — installable from npm as @arguslab/argus. Pre-1.0: the surface is still free to change between minor versions.

The runner works and ships. What is missing is test-authoring surface.

Done and verified

• Hermes-native execution: sealed IIFE per test file, spawn-per-file, nonce-framed result channel, hardened against forgery and prototype pollution.
• Test discovery with globs, bounded-concurrency parallel execution.
• Jest-shaped surface: describe / test / it, the four hooks, .skip / .only / .todo, async tests, expect.extend, assertion counting.
• Matcher set: equality, truthiness, numeric, string, collection, object, toThrow, .resolves / .rejects, call and return matchers.
• Source maps — failure stacks remapped to the original TypeScript.
• React Native native mocks: NativeModules / TurboModuleRegistry shims plus a user-facing registration API. argus.fn() and argus.spyOn().
• Component testing on real React inside Hermes: render, rerender, unmount, screen, synchronous queries, waitFor, waitForElementToBeRemoved, findBy* / findAllBy*, within, fireEvent, act.
• Engine and version resolution from the project’s own React Native install, with the offline lookup table as fallback.
• The Hermes build-and-publish pipeline, gated on bytecode parity with the official hermes-compiler — with the first release cut: hermes-bin-v250829098.0.16, V1, all four platforms, covering React Native 0.86 and 0.87.
• A configuration file — argus.config.ts loaded through Node’s own type stripping, so it needs no transpiler and adds no dependency.
• The syntax envelope, documented for both engines and derived from real binaries instead of prose. test/hermes-syntax-probe.test.ts checks the policy against whichever VMs are present, which is what caught two long-standing errors: legacy runs async function and rejects only the arrow form, and V1 rejects async function* exactly as legacy does, so it is not a superset.
• Host-side unit tests plus a separately asserted set of passing, intentionally failing, and adversarial Hermes fixtures.

Shipped in v0.1.0 — distribution

Argus is installable. This was the milestone everything else waited behind.

• One published package, @arguslab/argus, exposing the argus bin. The other seven workspace packages are private and never reach the registry — see Package map.
• A build pipeline staging the tarball: host code bundled to a single ESM binary, the Hermes-side sources copied verbatim as TypeScript runtime assets. 30 files, 68 kB packed, 246 kB unpacked, 300 kB installed.
• Path resolution anchored to the CLI module’s own location instead of the monorepo layout, so the framework and polyfills are found in both the development and installed shapes.
• React resolved from the user’s project rather than relative to the component-testing package. React and test-renderer are optional peers; a pure-TypeScript suite runs with neither installed.
• Complete package metadata: license, repository, description, files, engines (node >= 24), publishConfig.access: public.
• Types for the virtual argus module and the test globals.

That last one comes with a caveat the docs state plainly rather than glossing: it is not zero-config. TypeScript only auto-loads ambient declarations from node_modules/@types/*, so consumers add "types": ["@arguslab/argus"] or one triple-slash reference. See Installation → TypeScript.

Still open in the engine and provisioning work

• Scope the class-lowering plugin to the legacy target only. Today it is scoped to dependencies — node_modules JavaScript containing class syntax — and runs regardless of engine. Correct and cheap, but broader than it needs to be on V1, whose parser handles classes natively.
• Refresh the RN-to-Hermes lookup table in CI from the published branches table. The table exists and is correct; refreshing it is manual.
• Cut the remaining hermes-bin-v* releases. Only hermes-bin-v250829098.0.16 is published — it covers React Native 0.86 and 0.87 and nothing else. The prebuilt step 404s on RN 0.83–0.85, and on the date-based legacy pins of RN 0.78–0.82 it cannot apply at all, because a date ref cannot name a release version. Those fall through to the bundled macOS VM where it exists and to --provision everywhere else — which is the whole of Linux below RN 0.86.
• Re-cut the published Linux archives. The ones on the release page require glibc 2.38, so they refuse to start on Ubuntu 22.04 LTS, Debian 12, Amazon Linux 2023 and RHEL 9. The build now targets the oldest supported runner and a gate reads the requirement out of the ELF and fails above 2.35, but that landed after the release was cut, so the fix is not in users’ hands until the binaries are rebuilt. musl distributions such as Alpine stay out of reach regardless. See Prebuilt binaries.

Shipped in v0.2.0 — configuration

Globs, ignores, timeout, concurrency and engine selection were hardcoded or reachable only as flags. That blocked everything below, because snapshots, coverage and watch all need somewhere to be configured. Full reference: Configuration.

• ArgusConfig and defineConfig exported from the package, with documented defaults.
• Loader, validator and merge layer, wired through discovery, bundling and provisioning. Loading uses native import() — Node type-strips argus.config.ts directly, so this needed no dependency and no bundler.
• First hit wins across argus.config.ts, .mts, .js, .mjs, .config/argus.config.ts and a package.json field; configs are never merged, and the upward walk stops at the first package.json. --config <path> names one directly.
• Precedence, lowest to highest: defaults → package.json field → config file → environment → CLI flags.
• include / exclude replacing the hardcoded globs — and the hardcoded node_modules substring check, which had been silently skipping any directory whose name merely contained that string.

Two behaviour changes came with it, both covered in Changes in 0.2.0: discovery now excludes dist, build and coverage by default, and --timeout rejects a value it cannot parse instead of falling back to 10 000 ms.

Still open here:

• passWithNoTests — a zero-match run currently exits 2.
• esbuild target, module aliases and the JSX runtime are still fixed.

Next — test-authoring features

The next milestone. It is deliberately unnumbered: which release these land in is not decided, and naming one here would be a promise this page cannot keep. None of them blocked installability; all of them are the reason someone would ask for the release after this one.

Snapshots, coverage, watch

• Snapshots — toMatchSnapshot(), external .snap files, --update, obsolete detection and safe pruning. Design work is complete.
• Coverage — provider selection, thresholds, reporters.
• Watch mode — file watching, re-run on change, interactive filtering. Worth splitting compile from execute here: hermesc -emit-binary to a cached .hbc, then hvm to run it. Measured at roughly four times faster on re-runs, because compilation dominates and the cache absorbs it.

Component testing

waitFor, waitForElementToBeRemoved, and findBy* / findAllBy* now stop on the first of two limits: real wall-clock time or a scheduler-turn budget. The second limit is required because standalone Hermes exposes timers but ignores their delay.

Done: userEvent and fake timers with an explicit clock. Fake timers are a fidelity fix on standalone Hermes: unlike the native FIFO queue, they preserve elapsed-time semantics.

CI

• macOS and Linux matrix. CI is ubuntu-latest only, so nothing is exercised on the platform most contributors develop on.

Done: the release workflow for the npm package. @arguslab/argus is published from CI with signed provenance, authenticated by npm trusted publishing over OIDC so no token is stored in the repository. v0.1.0 predates it and was published by hand, so it carries no attestation; v0.1.1 and everything after does.

Later

• Reporters — pluggable output, JSON and JUnit for CI.
• CLI framework migration — worth doing once a second subcommand exists (init, watch). Until then the built-in parser is adequate.
• argus init — scaffold a config file.
• Windows support — needs a prebuilt VM for win32-x64 or a documented source-build path. Unsupported today in any form.
• Broader React Native range — validate and document which versions work.
• Setup files — user-supplied global setup and teardown.
• bail / fail-fast, retry, test-name filtering.

Deliberate non-goals

Running on a device, full Jest compatibility, replacing Vitest for non-RN projects, and bundling a JavaScript engine other than Hermes. Reasoning: Limitations & non-goals.

Publishing the internal packages is also a non-goal. core, the adapters and the reporter are a hexagonal seam, not an API; framework and rntl are never imported by Node at all. See Package map.