feat(core): reload config on filesystem changes

packages/core/src/config.ts

@@ -3,18 +3,19 @@ export * as Config from "./config"
 import { makeLocationNode } from "./effect/app-node"
 import path from "path"
 import { type ParseError, parse } from "jsonc-parser"
-import { Context, Effect, Layer, Option, Schema } from "effect"
+import { Context, Effect, Fiber, Layer, Option, PubSub, Schema, Stream } from "effect"
 import { Permission } from "@opencode-ai/schema/permission"
+import { Config as ConfigSchema } from "@opencode-ai/schema/config"
+import { EventV2 } from "./event"
+import { Watcher } from "./filesystem/watcher"
 import { FSUtil } from "./fs-util"
 import { Global } from "./global"
 import { Location } from "./location"
-import { Policy } from "./policy"
 import { AbsolutePath } from "./schema"
 import { ConfigAgent } from "./config/agent"
 import { ConfigAttachments } from "./config/attachments"
 import { ConfigCompaction } from "./config/compaction"
 import { ConfigCommand } from "./config/command"
-import { ConfigExperimental } from "./config/experimental"
 import { ConfigFormatter } from "./config/formatter"
 import { ConfigLSP } from "./config/lsp"
 import { ConfigMCP } from "./config/mcp"
@@ -102,7 +103,6 @@ export class Info extends Schema.Class<Info>("Config.Info")({
   plugins: ConfigPlugin.Plugins.pipe(Schema.optional).annotate({
     description: "Ordered external plugin packages to load",
   }),
-  experimental: ConfigExperimental.Experimental.pipe(Schema.optional),
   providers: Schema.Record(Schema.String, ConfigProvider.Info).pipe(Schema.optional),
 }) {}
 
@@ -138,7 +138,8 @@ const layer = Layer.effect(
     const fs = yield* FSUtil.Service
     const global = yield* Global.Service
     const location = yield* Location.Service
-    const policy = yield* Policy.Service
+    const watcher = yield* Watcher.Service
+    const events = yield* EventV2.Service
     const names = ["opencode.json", "opencode.jsonc"]
     const decodeOptions = { errors: "all", onExcessProperty: "ignore", propertyOrder: "original" } as const
     const decodeInfo = Schema.decodeUnknownOption(Info, decodeOptions)
@@ -170,45 +171,78 @@ const layer = Layer.effect(
       ]
     })
 
-    const globalDirectory = AbsolutePath.make(global.config)
-    const locationIsGlobal = path.resolve(location.directory) === path.resolve(global.config)
-    // Read configuration once when this location opens. Later calls reuse these
-    // values until the location is reopened.
-    const discovered = locationIsGlobal
-      ? []
-      : yield* fs
-          .up({
-            targets: [".opencode", ...names.toReversed()],
-            start: location.directory,
-            stop: location.project.directory,
-          })
-          .pipe(Effect.orDie)
-    const directories = [
-      globalDirectory,
-      ...discovered
-        .filter((item) => path.basename(item) === ".opencode")
-        .toReversed()
-        .map((directory) => AbsolutePath.make(directory)),
+    const discover = Effect.fn("Config.discover")(function* () {
+      const globalDirectory = AbsolutePath.make(global.config)
+      const locationIsGlobal = path.resolve(location.directory) === path.resolve(global.config)
+      const discovered = locationIsGlobal
+        ? []
+        : yield* fs
+            .up({
+              targets: [".opencode", ...names.toReversed()],
+              start: location.directory,
+              stop: location.project.directory,
+            })
+            .pipe(Effect.orDie)
+      const directories = [
+        globalDirectory,
+        ...discovered
+          .filter((item) => path.basename(item) === ".opencode")
+          .toReversed()
+          .map((directory) => AbsolutePath.make(directory)),
+      ]
+      const directPaths = discovered.filter((item) => path.basename(item) !== ".opencode").toReversed()
+      const direct = yield* Effect.forEach(directPaths, loadFile).pipe(
+        Effect.orDie,
+        Effect.map((configs) => configs.filter((config): config is Document => config !== undefined)),
+      )
+      const supplementary = yield* Effect.forEach(directories, loadDirectory).pipe(Effect.orDie)
+      return {
+        entries: [...(supplementary[0] ?? []), ...direct, ...supplementary.slice(1).flat()],
+        directories,
+        files: directPaths,
+      }
+    })
+
+    const initial = yield* discover()
+    let configs = initial.entries
+    const updates = yield* PubSub.unbounded<Watcher.Update>()
+    const subscriptions = new Map<string, Effect.Effect<unknown>>()
+    const targets = (snapshot: typeof initial) => [
+      ...snapshot.directories.map((path) => ({ path, type: "directory" as const })),
+      ...snapshot.files
+        .filter((file) => !snapshot.directories.some((directory) => FSUtil.contains(directory, file)))
+        .map((path) => ({ path, type: "file" as const })),
     ]
-    // A config closer to the opened directory should win over one higher up.
-    // Search starts nearby, so reverse the results before applying them.
-    const directPaths = discovered.filter((item) => path.basename(item) !== ".opencode").toReversed()
-    const direct = yield* Effect.forEach(directPaths, loadFile).pipe(
-      Effect.orDie,
-      Effect.map((configs) => configs.filter((config): config is Document => config !== undefined)),
-    )
-    const supplementary = yield* Effect.forEach(directories, loadDirectory).pipe(Effect.orDie)
-    // Apply general settings first and more specific settings last:
-    // global config, project files, then `.opencode` files.
-    const configs = [...(supplementary[0] ?? []), ...direct, ...supplementary.slice(1).flat()]
-    // Rules use the opposite order so a user-global rule can override a
-    // repository rule. Statement order inside each file stays unchanged.
-    yield* policy.load(
-      configs
-        .filter((config): config is Document => config.type === "document")
-        .toReversed()
-        .flatMap((config) => config.info.experimental?.policies ?? []),
+    const reconcile = Effect.fn("Config.reconcileWatches")(function* (snapshot: typeof initial) {
+      const next = new Map(targets(snapshot).map((target) => [JSON.stringify(target), target]))
+      for (const [key, stop] of subscriptions) {
+        if (next.has(key)) continue
+        yield* stop
+        subscriptions.delete(key)
+      }
+      for (const [key, target] of next) {
+        if (subscriptions.has(key)) continue
+        const fiber = yield* watcher.subscribe(target).pipe(
+          Stream.runForEach((update) => PubSub.publish(updates, update)),
+          Effect.forkScoped({ startImmediately: true }),
+        )
+        subscriptions.set(key, Fiber.interrupt(fiber))
+      }
+    })
+
+    yield* Stream.fromPubSub(updates).pipe(
+      Stream.debounce("100 millis"),
+      Stream.runForEach((update) =>
+        Effect.gen(function* () {
+          const next = yield* discover()
+          configs = next.entries
+          yield* reconcile(next)
+          yield* events.publish(ConfigSchema.Event.Updated, {})
+        }).pipe(Effect.catchCause((cause) => Effect.logError("failed to reload config", { path: update.path, cause }))),
+      ),
+      Effect.forkScoped({ startImmediately: true }),
     )
+    yield* reconcile(initial)
 
     return Service.of({
       entries: Effect.fn("Config.entries")(function* () {
@@ -221,5 +255,5 @@ const layer = Layer.effect(
 export const node = makeLocationNode({
   service: Service,
   layer,
-  deps: [FSUtil.node, Global.node, Location.node, Policy.node],
+  deps: [Watcher.node, EventV2.node, FSUtil.node, Global.node, Location.node],
 })