Module src

Public-surface barrel for @causl/causl-wasm-ts.

Re-exports the canonical seven-method API — createCausl, graph.input, graph.derived, graph.commit, graph.read, graph.subscribe, graph.explain — together with the second-tier extensions justified individually on the Graph interface (subscribeCommits, commitLog, exportModel, simulate, snapshot, hydrate, readAt, snapshotAt, now), the structured error classes for the race-class catalogue, and the CauslModel IR plus its JSON Schema document — the bridge from the TypeScript engine to the Rust causl-check bounded model checker.

Consumers should rely on this barrel; deep imports into individual modules are not part of the supported surface.

One engine, and createCausl() is construct-or-throw

@causl/causl-wasm-ts is driven by the Rust→WASM core (SPEC §18A.13), and as of 0.5.0 (causl/causl-wasm-ts#280) that is the ONLY engine it ships. The CUT (epic #31 / issue #34) removed the TypeScript engine factory from this barrel; 0.5.0 removed the two options that still reached the TypeScript floor (CreateCauslOptions.engine, CreateCauslOptions.backend) and withdrew the SPEC §18A.13.1 capability fallback that used to substitute the floor on a host where WasmGC could not instantiate. The two supported public entry points are:

• createCausl(options) — the default factory, and synchronous. It returns the real wasm engine when @causl/causl-wasm-ts/wasm has been preloaded for the default bridge, and otherwise throws during construction — before any Graph is returned, with no partially-built graph and no async window. There is no TypeScript-floor return value any more.
• createCauslWasm(options) — the async wasm factory, exported from the @causl/causl-wasm-ts/wasm subpath (kept out of the main bundle). This is the SPEC §18A backend contract: the same seven-method spine, driven by the Rust→WASM core through a thin marshalling bridge.

The boot sequence is one await, once:

import { preloadCauslWasm } from '@causl/causl-wasm-ts/wasm'
import { createCausl } from '@causl/causl-wasm-ts'

await preloadCauslWasm()   // ONCE, at app init — and in your test setup
const graph = createCausl()
Copy

Four construction failures are possible. For the three ENGINE-REACHABILITY ones, branch on err.code, never on instanceof, because the main bundle's WasmEngineUnavailableError twin cannot extend the /wasm class (the bundle-no-wasm-leak gate): CAUSL_WASM_ENGINE_UNAVAILABLE (the /wasm subpath was never imported in this process, or the host cannot instantiate WasmGC) and CAUSL_WASM_NOT_PRELOADED (imported, but preloadCauslWasm() never resolved). isCauslEngineUnavailable is the guard for both.

The fourth is not about the engine at all: CAUSL_REMOVED_ENGINE_OPTION (RemovedEngineOptionError), raised when the options bag still carries engine / backend / fallbackToTs / fallbackToJs — the four 0.5.0 removed. It is ONE class from one module, so instanceof is a correct test here; isRemovedEngineOption is provided so both families read alike. The ## [0.5.0] section of CHANGELOG.md is the authoritative failure contract and numbered migration.

The pure-TS closure still exists INTERNALLY (the wasm path wraps it as its structural / handle / dependency layer) but is not a public engine choice and is no longer a fallback; deleting it outright is EPIC causl/causl-wasm-ts#275 and has not landed. loadWasmBackend is not an adopter entry point — it is a determinism-gate shim that wraps a plain instance of that same closure, it does not satisfy createCausl()'s preload precondition, and the backend option that consumed its return value was removed in 0.5.0. See the @causl/causl-wasm-ts/wasm module for preloadCauslWasm, createCauslWasmSync, BackendEngine and the Bridge FFI surface.