test(core): simplify file mutation layer wiring

packages/core/src/file-mutation.ts

@@ -3,6 +3,7 @@ export * as FileMutation from "./file-mutation"
 import { Context, Effect, Layer, Schema } from "effect"
 import { dirname } from "path"
 import { KeyedMutex } from "./effect/keyed-mutex"
+import { LayerNode } from "./effect/layer-node"
 import { FSUtil } from "./fs-util"
 
 export interface Target {
@@ -171,6 +172,8 @@ export const layer = Layer.effect(
   }),
 )
 
+export const node = LayerNode.make(layer, [FSUtil.node])
+
 function splitBom(text: string) {
   const stripped = text.replace(/^\uFEFF+/, "")
   return { bom: stripped.length !== text.length, text: stripped }

packages/core/src/instruction-context.ts

@@ -9,7 +9,6 @@ import { Location } from "./location"
 import { AbsolutePath } from "./schema"
 import { SystemContext } from "./system-context/index"
 import { SystemContextRegistry } from "./system-context/registry"
-import { LayerNode } from "./effect/layer-node"
 
 class File extends Schema.Class<File>("InstructionContext.File")({
   path: AbsolutePath,
@@ -88,9 +87,6 @@ export const layer = Layer.effectDiscard(
   }),
 )
 
-export const node = (location: LayerNode.Node<Location.Service>) =>
-  LayerNode.make(layer, [FSUtil.node, Global.node, location, SystemContextRegistry.node])
-
 function render(files: ReadonlyArray<File>) {
   return files.map((file) => `Instructions from: ${file.path}\n${file.content}`).join("\n\n")
 }

packages/core/src/location-mutation.ts

@@ -2,6 +2,7 @@ export * as LocationMutation from "./location-mutation"
 
 import path from "path"
 import { Context, Effect, Layer, Schema } from "effect"
+import { LayerNode } from "./effect/layer-node"
 import { FSUtil } from "./fs-util"
 import { Location } from "./location"
 
@@ -153,3 +154,5 @@ export const layer = Layer.effect(
 )
 
 export const locationLayer = layer
+
+export const node = (location: LayerNode.Node<Location.Service>) => LayerNode.make(layer, [FSUtil.node, location])

packages/core/src/system-context/registry.ts

@@ -1,7 +1,6 @@
 export * as SystemContextRegistry from "./registry"
 
 import { Context, Effect, Layer, Ref, Scope } from "effect"
-import { LayerNode } from "../effect/layer-node"
 import { SystemContext } from "./index"
 
 export interface Entry {
@@ -45,5 +44,3 @@ export const layer = Layer.effect(
     })
   }),
 )
-
-export const node = LayerNode.make(layer, [])

packages/core/test/file-mutation.test.ts

@@ -2,6 +2,7 @@ import fs from "fs/promises"
 import path from "path"
 import { describe, expect } from "bun:test"
 import { Deferred, Effect, Fiber, Layer } from "effect"
+import { LayerNode } from "@opencode-ai/core/effect/layer-node"
 import { FileMutation } from "@opencode-ai/core/file-mutation"
 import { FSUtil } from "@opencode-ai/core/fs-util"
 import { Location } from "@opencode-ai/core/location"
@@ -11,14 +12,16 @@ import { location } from "./fixture/location"
 import { tmpdir } from "./fixture/tmpdir"
 import { it } from "./lib/effect"
 
-function provide(directory: string, filesystem = FSUtil.defaultLayer) {
-  const activeLocation = Layer.succeed(
-    Location.Service,
-    Location.Service.of(location({ directory: AbsolutePath.make(directory) })),
+function provide(directory: string, filesystem?: LayerNode.Replacement<FSUtil.Service>) {
+  const activeLocation = LayerNode.make(
+    Layer.succeed(Location.Service, Location.Service.of(location({ directory: AbsolutePath.make(directory) }))),
+    [],
+  )
+  return Effect.provide(
+    LayerNode.buildLayer(LayerNode.group([LocationMutation.node(activeLocation), FileMutation.node]), {
+      replacements: filesystem ? [filesystem] : [],
+    }),
   )
-  const resolution = LocationMutation.layer.pipe(Layer.provide(filesystem), Layer.provide(activeLocation))
-  const mutation = FileMutation.layer.pipe(Layer.provide(filesystem))
-  return Effect.provide(Layer.mergeAll(resolution, mutation))
 }
 
 function withTmp<A, E, R>(f: (directory: string) => Effect.Effect<A, E, R>) {
@@ -347,17 +350,20 @@ describe("FileMutation", () => {
 })
 
 function instrumentWrites(run: <E>(write: Effect.Effect<void, E>, target: string) => Effect.Effect<void, E>) {
-  return Layer.effect(
-    FSUtil.Service,
-    Effect.gen(function* () {
-      const filesystem = yield* FSUtil.Service
-      return FSUtil.Service.of({
-        ...filesystem,
-        writeWithDirs: (target, content, mode) => run(filesystem.writeWithDirs(target, content, mode), target),
-        writeFile: (target, content, options) => run(filesystem.writeFile(target, content, options), target),
-        writeFileString: (target, content, options) =>
-          run(filesystem.writeFileString(target, content, options), target),
-      })
-    }),
-  ).pipe(Layer.provide(FSUtil.defaultLayer))
+  return LayerNode.replace(
+    FSUtil.node,
+    Layer.effect(
+      FSUtil.Service,
+      Effect.gen(function* () {
+        const filesystem = yield* FSUtil.Service
+        return FSUtil.Service.of({
+          ...filesystem,
+          writeWithDirs: (target, content, mode) => run(filesystem.writeWithDirs(target, content, mode), target),
+          writeFile: (target, content, options) => run(filesystem.writeFile(target, content, options), target),
+          writeFileString: (target, content, options) =>
+            run(filesystem.writeFileString(target, content, options), target),
+        })
+      }),
+    ).pipe(Layer.provide(LayerNode.buildLayer(FSUtil.node))),
+  )
 }

packages/core/test/instruction-context.test.ts

@@ -5,7 +5,6 @@ import path from "path"
 import { FSUtil } from "@opencode-ai/core/fs-util"
 import { Global } from "@opencode-ai/core/global"
 import { InstructionContext } from "@opencode-ai/core/instruction-context"
-import { LayerNode } from "@opencode-ai/core/effect/layer-node"
 import { Location } from "@opencode-ai/core/location"
 import { AbsolutePath } from "@opencode-ai/core/schema"
 import { SystemContext } from "@opencode-ai/core/system-context"
@@ -14,28 +13,7 @@ import { location } from "./fixture/location"
 import { tmpdir } from "./fixture/tmpdir"
 import { testEffect } from "./lib/effect"
 
-const it = testEffect(LayerNode.buildLayer(FSUtil.node))
-
-function provide(options: {
-  global: string
-  location: Location.Interface
-  filesystem?: FSUtil.Interface
-}) {
-  const location = LayerNode.make(
-    Layer.succeed(Location.Service, Location.Service.of(options.location)),
-    [],
-  )
-  return Effect.provide(
-    LayerNode.buildLayer(LayerNode.group([InstructionContext.node(location), SystemContextRegistry.node]), {
-      replacements: [
-        LayerNode.replace(Global.node, Global.layerWith({ config: options.global })),
-        ...(options.filesystem
-          ? [LayerNode.replace(FSUtil.node, Layer.succeed(FSUtil.Service, FSUtil.Service.of(options.filesystem)))]
-          : []),
-      ],
-    }),
-  )
-}
+const it = testEffect(Layer.empty)
 
 describe("InstructionContext", () => {
   it.live("loads global and upward project AGENTS.md files as one aggregate context", () =>
@@ -63,13 +41,20 @@ describe("InstructionContext", () => {
 
           const load = SystemContextRegistry.Service.pipe(
             Effect.flatMap((service) => service.load()),
-            provide({
-              global,
-              location: location(
-                { directory: AbsolutePath.make(directory) },
-                { projectDirectory: AbsolutePath.make(project) },
+            Effect.provide(InstructionContext.layer.pipe(Layer.provideMerge(SystemContextRegistry.layer))),
+            Effect.provide(FSUtil.defaultLayer),
+            Effect.provide(Global.layerWith({ config: global })),
+            Effect.provide(
+              Layer.succeed(
+                Location.Service,
+                Location.Service.of(
+                  location(
+                    { directory: AbsolutePath.make(directory) },
+                    { projectDirectory: AbsolutePath.make(project) },
+                  ),
+                ),
               ),
-            }),
+            ),
           )
 
           const initialized = yield* SystemContext.initialize(yield* load)
@@ -122,10 +107,15 @@ describe("InstructionContext", () => {
           yield* Effect.promise(() => fs.writeFile(file, ""))
           const context = yield* SystemContextRegistry.Service.pipe(
             Effect.flatMap((service) => service.load()),
-            provide({
-              global: path.join(tmp.path, "global"),
-              location: location({ directory: AbsolutePath.make(tmp.path) }),
-            }),
+            Effect.provide(InstructionContext.layer.pipe(Layer.provideMerge(SystemContextRegistry.layer))),
+            Effect.provide(FSUtil.defaultLayer),
+            Effect.provide(Global.layerWith({ config: path.join(tmp.path, "global") })),
+            Effect.provide(
+              Layer.succeed(
+                Location.Service,
+                Location.Service.of(location({ directory: AbsolutePath.make(tmp.path) })),
+              ),
+            ),
           )
 
           expect((yield* SystemContext.initialize(context)).baseline).toBe(`Instructions from: ${file}\n`)
@@ -136,14 +126,22 @@ describe("InstructionContext", () => {
 
   it.effect("preserves admitted instructions while observation is unavailable", () =>
     Effect.gen(function* () {
-      const fs = yield* FSUtil.Service
+      const failingFS = Layer.effect(
+        FSUtil.Service,
+        FSUtil.Service.pipe(
+          Effect.map((fs) =>
+            FSUtil.Service.of({ ...fs, up: () => Effect.fail(new FSUtil.FileSystemError({ method: "up" })) }),
+          ),
+        ),
+      ).pipe(Layer.provide(FSUtil.defaultLayer))
       const context = yield* SystemContextRegistry.Service.pipe(
         Effect.flatMap((service) => service.load()),
-        provide({
-          global: "/global",
-          location: location({ directory: AbsolutePath.make("/repo") }),
-          filesystem: { ...fs, up: () => Effect.fail(new FSUtil.FileSystemError({ method: "up" })) },
-        }),
+        Effect.provide(InstructionContext.layer.pipe(Layer.provideMerge(SystemContextRegistry.layer))),
+        Effect.provide(failingFS),
+        Effect.provide(Global.layerWith({ config: "/global" })),
+        Effect.provide(
+          Layer.succeed(Location.Service, Location.Service.of(location({ directory: AbsolutePath.make("/repo") }))),
+        ),
       )
 
       expect(
@@ -160,18 +158,26 @@ describe("InstructionContext", () => {
   it.effect("preserves admitted instructions when a discovered file disappears before read", () =>
     Effect.gen(function* () {
       const file = AbsolutePath.make("/repo/AGENTS.md")
-      const fs = yield* FSUtil.Service
+      const racingFS = Layer.effect(
+        FSUtil.Service,
+        FSUtil.Service.pipe(
+          Effect.map((fs) =>
+            FSUtil.Service.of({
+              ...fs,
+              up: () => Effect.succeed([file]),
+              readFileStringSafe: () => Effect.succeed(undefined),
+            }),
+          ),
+        ),
+      ).pipe(Layer.provide(FSUtil.defaultLayer))
       const context = yield* SystemContextRegistry.Service.pipe(
         Effect.flatMap((service) => service.load()),
-        provide({
-          global: "/global",
-          location: location({ directory: AbsolutePath.make("/repo") }),
-          filesystem: {
-            ...fs,
-            up: () => Effect.succeed([file]),
-            readFileStringSafe: () => Effect.succeed(undefined),
-          },
-        }),
+        Effect.provide(InstructionContext.layer.pipe(Layer.provideMerge(SystemContextRegistry.layer))),
+        Effect.provide(racingFS),
+        Effect.provide(Global.layerWith({ config: "/global" })),
+        Effect.provide(
+          Layer.succeed(Location.Service, Location.Service.of(location({ directory: AbsolutePath.make("/repo") }))),
+        ),
       )
 
       expect(
@@ -188,25 +194,35 @@ describe("InstructionContext", () => {
   it.effect("canonicalizes upward discovery boundaries", () =>
     Effect.gen(function* () {
       let observed: { targets: string[]; start: string; stop?: string } | undefined
-      const fs = yield* FSUtil.Service
+      const observingFS = Layer.effect(
+        FSUtil.Service,
+        FSUtil.Service.pipe(
+          Effect.map((fs) =>
+            FSUtil.Service.of({
+              ...fs,
+              up: (options) =>
+                Effect.sync(() => {
+                  observed = options
+                  return []
+                }),
+            }),
+          ),
+        ),
+      ).pipe(Layer.provide(FSUtil.defaultLayer))
 
       yield* SystemContextRegistry.Service.pipe(
         Effect.flatMap((service) => service.load()),
-        provide({
-          global: "/global",
-          location: location(
-            { directory: AbsolutePath.make("/repo/") },
-            { projectDirectory: AbsolutePath.make("/repo") },
+        Effect.provide(InstructionContext.layer.pipe(Layer.provideMerge(SystemContextRegistry.layer))),
+        Effect.provide(observingFS),
+        Effect.provide(Global.layerWith({ config: "/global" })),
+        Effect.provide(
+          Layer.succeed(
+            Location.Service,
+            Location.Service.of(
+              location({ directory: AbsolutePath.make("/repo/") }, { projectDirectory: AbsolutePath.make("/repo") }),
+            ),
           ),
-          filesystem: {
-            ...fs,
-            up: (options) =>
-              Effect.sync(() => {
-                observed = options
-                return []
-              }),
-          },
-        }),
+        ),
       )
 
       expect(observed).toEqual({
@@ -222,15 +238,22 @@ describe("InstructionContext", () => {
       const previous = process.env.OPENCODE_DISABLE_PROJECT_CONFIG
       let scanned = false
       process.env.OPENCODE_DISABLE_PROJECT_CONFIG = "1"
-      const fs = yield* FSUtil.Service
 
       yield* SystemContextRegistry.Service.pipe(
         Effect.flatMap((service) => service.load()),
-        provide({
-          global: "/global",
-          location: location({ directory: AbsolutePath.make("/repo") }),
-          filesystem: { ...fs, up: () => Effect.sync(() => ((scanned = true), [])) },
-        }),
+        Effect.provide(InstructionContext.layer.pipe(Layer.provideMerge(SystemContextRegistry.layer))),
+        Effect.provide(
+          Layer.effect(
+            FSUtil.Service,
+            FSUtil.Service.pipe(
+              Effect.map((fs) => FSUtil.Service.of({ ...fs, up: () => Effect.sync(() => ((scanned = true), [])) })),
+            ),
+          ).pipe(Layer.provide(FSUtil.defaultLayer)),
+        ),
+        Effect.provide(Global.layerWith({ config: "/global" })),
+        Effect.provide(
+          Layer.succeed(Location.Service, Location.Service.of(location({ directory: AbsolutePath.make("/repo") }))),
+        ),
         Effect.ensuring(
           Effect.sync(() => {
             if (previous === undefined) delete process.env.OPENCODE_DISABLE_PROJECT_CONFIG
@@ -246,17 +269,26 @@ describe("InstructionContext", () => {
   it.effect("does not discover project instructions outside the canonical project root", () =>
     Effect.gen(function* () {
       let scanned = false
-      const fs = yield* FSUtil.Service
       yield* SystemContextRegistry.Service.pipe(
         Effect.flatMap((service) => service.load()),
-        provide({
-          global: "/global",
-          location: location(
-            { directory: AbsolutePath.make("/outside") },
-            { projectDirectory: AbsolutePath.make("/repo") },
+        Effect.provide(InstructionContext.layer.pipe(Layer.provideMerge(SystemContextRegistry.layer))),
+        Effect.provide(
+          Layer.effect(
+            FSUtil.Service,
+            FSUtil.Service.pipe(
+              Effect.map((fs) => FSUtil.Service.of({ ...fs, up: () => Effect.sync(() => ((scanned = true), [])) })),
+            ),
+          ).pipe(Layer.provide(FSUtil.defaultLayer)),
+        ),
+        Effect.provide(Global.layerWith({ config: "/global" })),
+        Effect.provide(
+          Layer.succeed(
+            Location.Service,
+            Location.Service.of(
+              location({ directory: AbsolutePath.make("/outside") }, { projectDirectory: AbsolutePath.make("/repo") }),
+            ),
           ),
-          filesystem: { ...fs, up: () => Effect.sync(() => ((scanned = true), [])) },
-        }),
+        ),
       )
 
       expect(scanned).toBe(false)