feat(core): add V2 formatter runtime (#39564)

packages/core/test/tool-write.test.ts

@@ -3,6 +3,7 @@ import path from "path"
 import { describe, expect } from "bun:test"
 import { Effect, Layer } from "effect"
 import { FileMutation } from "@opencode-ai/core/file-mutation"
+import { Formatter } from "@opencode-ai/core/formatter"
 import { AppNodeBuilder } from "@opencode-ai/core/effect/app-node-builder"
 import { LayerNode } from "@opencode-ai/util/effect/layer-node"
 import { FSUtil } from "@opencode-ai/util/fs-util"
@@ -22,12 +23,13 @@ import { toolIdentity, executeTool, registerToolPlugin, toolDefinitions } from "
 const writeToolNode = makeLocationNode({
   name: "test/write-tool-plugin",
   layer: Layer.effectDiscard(registerToolPlugin(WriteTool.Plugin)),
-  deps: [Tool.node, LocationMutation.node, FileMutation.node, Permission.node],
+  deps: [Tool.node, LocationMutation.node, FileMutation.node, Formatter.node, FSUtil.node, Permission.node],
 })
 
 const sessionID = Session.ID.make("ses_write_tool_test")
 const assertions: Permission.AssertInput[] = []
 const writes: string[] = []
+let formatFile = (_target: string): Effect.Effect<boolean> => Effect.succeed(false)
 let denyAction: string | undefined
 
 const permission = Layer.succeed(
@@ -55,9 +57,14 @@ const permission = Layer.succeed(
   }),
 )
 
+const formatter = Layer.mock(Formatter.Service, {
+  file: (target) => formatFile(target),
+})
+
 const reset = () => {
   assertions.length = 0
   writes.length = 0
+  formatFile = () => Effect.succeed(false)
   denyAction = undefined
 }
 
@@ -93,6 +100,7 @@ const withTool = <A, E, R>(directory: string, body: (registry: Tool.Interface) =
         [
           [FSUtil.node, filesystem],
           [Location.node, activeLocation],
+          [Formatter.node, formatter],
           [Permission.node, permission],
         ],
       ),
@@ -140,6 +148,30 @@ describe("WriteTool", () => {
     ),
   )
 
+  it.live("formats the committed file", () =>
+    Effect.acquireUseRelease(
+      Effect.promise(() => tmpdir()),
+      (tmp) => {
+        reset()
+        const target = path.join(tmp.path, "formatted.txt")
+        formatFile = (file) =>
+          Effect.promise(async () => {
+            await fs.writeFile(file, (await fs.readFile(file, "utf8")).toUpperCase())
+            return true
+          })
+        return withTool(tmp.path, (registry) =>
+          Effect.gen(function* () {
+            expect(yield* executeTool(registry, call({ path: "formatted.txt", content: "format me" }))).toMatchObject({
+              status: "completed",
+            })
+            expect(yield* Effect.promise(() => fs.readFile(target, "utf8"))).toBe("FORMAT ME")
+          }),
+        )
+      },
+      (tmp) => Effect.promise(() => tmp[Symbol.asyncDispose]()),
+    ),
+  )
+
   it.live("overwrites a relative existing file and reports that it wrote the file", () =>
     Effect.acquireUseRelease(
       Effect.promise(() => tmpdir()),
@@ -174,6 +206,11 @@ describe("WriteTool", () => {
         reset()
         const preserved = path.join(tmp.path, "preserved.txt")
         const deduplicated = path.join(tmp.path, "deduplicated.txt")
+        formatFile = (target) =>
+          Effect.promise(async () => {
+            await fs.writeFile(target, `\uFEFF\uFEFF\uFEFF${(await fs.readFile(target, "utf8")).replace(/^\uFEFF+/, "")}`)
+            return true
+          })
         return Effect.promise(() =>
           Promise.all([fs.writeFile(preserved, "\uFEFFbefore"), fs.writeFile(deduplicated, "\uFEFFbefore")]),
         ).pipe(