Upgrade to Effect RC.116 and native property testing

.changeset/effect-rc116.md

@@ -0,0 +1,11 @@
+---
+"@typeonce/effect-machine": minor
+"@typeonce/effect-machine-react": minor
+"@typeonce/effect-machine-devtools": minor
+---
+
+Upgrade Effect and companion packages to `4.0.0-rc.116`. Install matching Effect packages when upgrading.
+
+`MachineTest.scenarios`, `finiteModels`, and `runtimeCommands` now produce native `Arbitrary` values from `effect/unstable/arbitrary/Arbitrary`. Custom input, event, and command generators must use that module instead of FastCheck. Use `Arbitrary.schema(schema)` for schema-derived generators, `Arbitrary.array` for sequences, and `Arbitrary.sampleEffect` or `Arbitrary.checkEffect` to sample and check them. In `@effect/vitest`, replace `fastCheck: { numRuns }` with `arbitrary: { runs }`. Generate new replay tokens; earlier FastCheck seeds and paths do not reproduce the same cases.
+
+Command sequences shrink by removing irrelevant commands while retaining the remaining values. Fix finite-model verification of exit and entry paths when an ancestor's initial choice resolves inside an active compound state.

package.json

@@ -35,10 +35,10 @@
   },
   "devDependencies": {
     "@changesets/cli": "2.31.0",
-    "@effect/vitest": "4.0.0-rc.112",
+    "@effect/vitest": "4.0.0-rc.116",
     "@types/node": "25.7.0",
     "dprint": "0.55.2",
-    "effect": "4.0.0-rc.112",
+    "effect": "4.0.0-rc.116",
     "pagefind": "1.5.2",
     "tinybench": "2.9.0",
     "tstyche": "7.2.1",

packages/devtools/package.json

@@ -32,21 +32,21 @@
     "dev": "tsx src/bin.ts"
   },
   "dependencies": {
-    "@effect/platform-browser": "4.0.0-rc.112",
-    "@effect/platform-node": "4.0.0-rc.112",
-    "@effect/platform-node-shared": "4.0.0-rc.112",
+    "@effect/platform-browser": "4.0.0-rc.116",
+    "@effect/platform-node": "4.0.0-rc.116",
+    "@effect/platform-node-shared": "4.0.0-rc.116",
     "@typeonce/effect-machine": "workspace:^",
     "chokidar": "4.0.3",
     "elkjs": "0.12.0",
     "typescript": "6.0.3",
     "vite": "8.1.5"
   },
   "peerDependencies": {
-    "effect": "4.0.0-rc.112"
+    "effect": "4.0.0-rc.116"
   },
   "devDependencies": {
     "@types/node": "25.7.0",
-    "effect": "4.0.0-rc.112",
+    "effect": "4.0.0-rc.116",
     "tsx": "4.21.0"
   },
   "files": [

packages/devtools/src/bin.ts

@@ -12,37 +12,37 @@ import * as StaticSite from "./internal/staticSite.js"
 import * as MachineRegistry from "./MachineRegistry.js"
 import * as ProjectInspector from "./ProjectInspector.js"
 
-const root = Flag.directory("root", { mustExist: true }).pipe(
+const root = Flag.Directory("root", { mustExist: true }).pipe(
   Flag.withDescription("Project root to inspect"),
   Flag.withDefault(process.cwd())
 )
 
-const include = Flag.string("include").pipe(
+const include = Flag.String("include").pipe(
   Flag.withDescription("Machine source glob relative to the project root"),
   Flag.withDefault("**/src/**/*.{ts,tsx,mts,cts,js,jsx,mjs,cjs}")
 )
 
-const host = Flag.string("host").pipe(
+const host = Flag.String("host").pipe(
   Flag.withDescription("Host for the local visualizer"),
   Flag.withDefault("127.0.0.1")
 )
 
-const port = Flag.integer("port").pipe(
+const port = Flag.Int("port").pipe(
   Flag.withDescription("Port for the local visualizer"),
   Flag.withDefault(5173)
 )
 
-const open = Flag.boolean("open").pipe(
+const open = Flag.Boolean("open").pipe(
   Flag.withDescription("Open the visualizer in the default browser"),
   Flag.withDefault(false)
 )
 
-const watchPolling = Flag.boolean("watch-polling").pipe(
+const watchPolling = Flag.Boolean("watch-polling").pipe(
   Flag.withDescription("Use polling instead of native file-system events"),
   Flag.withDefault(false)
 )
 
-const outputDirectory = Flag.directory("out-dir").pipe(
+const outputDirectory = Flag.Directory("out-dir").pipe(
   Flag.withAlias("o"),
   Flag.withDescription("Directory to write the static website"),
   Flag.withDefault(".effect-machine/site")

packages/effect-machine-react/package.json

@@ -49,17 +49,17 @@
     "@typeonce/effect-machine": "workspace:^"
   },
   "peerDependencies": {
-    "@effect/atom-react": "4.0.0-rc.112",
-    "effect": "4.0.0-rc.112",
+    "@effect/atom-react": "4.0.0-rc.116",
+    "effect": "4.0.0-rc.116",
     "react": ">=19.0.0 <20.0.0",
     "scheduler": ">=0.25.0 <0.28.0"
   },
   "devDependencies": {
-    "@effect/atom-react": "4.0.0-rc.112",
+    "@effect/atom-react": "4.0.0-rc.116",
     "@testing-library/react": "16.3.0",
     "@types/react": "19.2.16",
     "@types/react-dom": "19.2.3",
-    "effect": "4.0.0-rc.112",
+    "effect": "4.0.0-rc.116",
     "jsdom": "27.2.0",
     "react": "19.2.7",
     "react-dom": "19.2.7",

packages/effect-machine/README.md

@@ -596,6 +596,26 @@ pass complete decoded objects when defining scenarios manually. Pure planner
 tests do not execute invokes or time. Use a started machine and a probe when
 those semantics matter.
 
+Generated scenarios, finite models, and runtime commands use
+`effect/unstable/arbitrary/Arbitrary`. Custom generator options accept native
+`Arbitrary` values. For example:
+
+```ts
+import * as Arbitrary from "effect/unstable/arbitrary/Arbitrary"
+
+const generated = MachineTest.scenarios(Counter, { maxEvents: 20 })
+const samples = yield* Arbitrary.sampleEffect(generated.arbitrary, {
+  count: 10,
+  seed: 42
+})
+```
+
+Use `Arbitrary.schema(schema)` to derive a generator and `Arbitrary.array(item,
+{ maxLength })` for custom sequences. `Arbitrary.checkEffect` checks properties
+and returns a replay token for a failing case. With `@effect/vitest`, configure
+property runs using `{ arbitrary: { runs: 100, seed: 42 } }`. FastCheck replay
+paths and seeds do not preserve the same generated cases after migration.
+
 ## Entrypoints
 
 ```ts

packages/effect-machine/package.json

@@ -70,12 +70,12 @@
     "test:types": "tstyche"
   },
   "peerDependencies": {
-    "effect": "4.0.0-rc.112"
+    "effect": "4.0.0-rc.116"
   },
   "devDependencies": {
-    "@effect/vitest": "4.0.0-rc.112",
+    "@effect/vitest": "4.0.0-rc.116",
     "@types/node": "25.7.0",
-    "effect": "4.0.0-rc.112",
+    "effect": "4.0.0-rc.116",
     "tinybench": "2.9.0",
     "tstyche": "7.2.1",
     "typescript": "6.0.3",

packages/effect-machine/src/internal/testing/machine/arbitrary.ts

@@ -1,6 +1,6 @@
 import * as Schema from "effect/Schema"
 import * as SchemaAST from "effect/SchemaAST"
-import { FastCheck } from "effect/testing"
+import * as Arbitrary from "effect/unstable/arbitrary/Arbitrary"
 
 /**
  * Warning emitted when schema arbitrary generation must enforce an opaque
@@ -39,8 +39,7 @@ const reportChecks = (
   path: ReadonlyArray<PropertyKey>
 ): void => {
   const visit = (check: SchemaAST.Check<unknown>, covered: boolean): void => {
-    const arbitrary = check.annotations?.arbitrary
-    const nextCovered = covered || arbitrary?.constraint !== undefined || arbitrary?.candidate !== undefined
+    const nextCovered = covered || check.annotations?.arbitraryConstraint !== undefined
     if (check._tag !== "Filter") {
       for (const child of check.checks) visit(child, nextCovered)
     } else if (!nextCovered) {
@@ -97,6 +96,14 @@ const reportFor = (ast: SchemaAST.AST): SchemaArbitraryReport => {
 
 /** @internal */
 export const toArbitraryWithReport = <S extends Schema.Constraint>(schema: S) => ({
-  value: Schema.toArbitrary(schema)(FastCheck),
+  value: Arbitrary.schema(schema),
   report: reportFor(schema.ast)
 })
+
+/** Selects one of the supplied generators without replacing its shrink tree. @internal */
+export const chooseArbitrary = <A>(
+  ...choices: readonly [Arbitrary.Arbitrary<A>, ...Array<Arbitrary.Arbitrary<A>>]
+): Arbitrary.Arbitrary<A> =>
+  Arbitrary.schema(Schema.Int.check(Schema.isBetween({ minimum: 0, maximum: choices.length - 1 }))).pipe(
+    Arbitrary.flatMap((index) => choices[index]!)
+  )