fix(core): bust external plugin import cache

packages/core/src/config/plugin/external.ts

@@ -3,6 +3,7 @@ export * as ConfigExternalPlugin from "./external"
 import type { Plugin as EffectPlugin } from "@opencode-ai/plugin/v2/effect"
 import type { Plugin as PromisePlugin } from "@opencode-ai/plugin/v2/promise"
 import { Effect, Schema, Stream } from "effect"
+import { createRequire } from "node:module"
 import path from "path"
 import { fileURLToPath, pathToFileURL } from "url"
 import { Config } from "../../config"
@@ -35,6 +36,9 @@ const PluginPackage = Schema.Struct({
   module: Schema.optional(Schema.String),
 })
 
+let importGeneration = 0
+const moduleCache = createRequire(import.meta.url).cache
+
 export const Plugin = define({
   id: "config-plugin",
   effect: Effect.fn(function* (ctx) {
@@ -106,7 +110,7 @@ export const Plugin = define({
             : (yield* npm.add(ref.package)).entrypoint
           if (!entrypoint) return
           yield* Effect.log({ msg: "loading plugin", id: ref.package, entrypoint })
-          const mod = yield* Effect.promise(() => import(entrypoint))
+          const mod = yield* Effect.promise(() => import(cacheBust(entrypoint)))
           const value = (yield* Schema.decodeUnknownEffect(PluginModule)(mod)).default
           const plugin = "effect" in value ? value : PluginPromise.fromPromise(value)
           return {
@@ -114,7 +118,11 @@ export const Plugin = define({
             effect: (host: Parameters<typeof plugin.effect>[0]) =>
               plugin.effect({ ...host, options: ref.options ?? {} }),
           }
-        }).pipe(Effect.catchCause(() => Effect.succeed(undefined))),
+        }).pipe(
+          Effect.catchCause((cause) =>
+            Effect.logError("failed to load plugin", { package: ref.package, cause }).pipe(Effect.as(undefined)),
+          ),
+        ),
       ).pipe(Effect.map((plugins) => plugins.filter((plugin) => plugin !== undefined)))
     })
     const reconcile = Effect.fn("ConfigExternalPlugin.reconcile")(function* () {
@@ -137,6 +145,13 @@ export const Plugin = define({
   }),
 })
 
+function cacheBust(entrypoint: string) {
+  const url = path.isAbsolute(entrypoint) ? pathToFileURL(entrypoint) : new URL(entrypoint)
+  if (url.protocol === "file:") delete moduleCache[fileURLToPath(url)]
+  url.searchParams.set("opencode-reload", String(++importGeneration))
+  return url.href
+}
+
 const resolvePackageEntrypoint = Effect.fnUntraced(function* (fs: FSUtil.Interface, directory: string) {
   const pkg = yield* fs.readJson(path.join(directory, "package.json")).pipe(
     Effect.flatMap(Schema.decodeUnknownEffect(PluginPackage)),

packages/core/test/config/plugin.test.ts

@@ -1,15 +1,19 @@
+import fs from "fs/promises"
 import path from "path"
 import { describe, expect } from "bun:test"
+import { Config as ConfigSchema } from "@opencode-ai/schema/config"
 import { Effect, Schema } from "effect"
 import { AgentV2 } from "@opencode-ai/core/agent"
 import { Config } from "@opencode-ai/core/config"
 import { ConfigExternalPlugin } from "@opencode-ai/core/config/plugin/external"
+import { EventV2 } from "@opencode-ai/core/event"
 import { FSUtil } from "@opencode-ai/core/fs-util"
 import { Location } from "@opencode-ai/core/location"
 import { Npm } from "@opencode-ai/core/npm"
 import { PluginV2 } from "@opencode-ai/core/plugin"
 import { PluginHost } from "@opencode-ai/core/plugin/host"
 import { AbsolutePath } from "@opencode-ai/core/schema"
+import { tmpdir } from "../fixture/tmpdir"
 import { testEffect } from "../lib/effect"
 import { PluginTestLayer } from "../plugin/fixture"
 
@@ -240,6 +244,49 @@ describe("ConfigExternalPlugin", () => {
       })
     }),
   )
+
+  it.live("reloads changed plugin source from the same entrypoint", () =>
+    Effect.acquireRelease(
+      Effect.promise(() => tmpdir()),
+      (tmp) => Effect.promise(() => tmp[Symbol.asyncDispose]()),
+    ).pipe(
+      Effect.flatMap((tmp) =>
+        Effect.gen(function* () {
+          const plugins = yield* PluginV2.Service
+          const agents = yield* AgentV2.Service
+          const events = yield* EventV2.Service
+          const fsUtil = yield* FSUtil.Service
+          const location = yield* Location.Service
+          const npm = yield* Npm.Service
+          const host = yield* PluginHost.make(plugins)
+          const plugin = path.join(tmp.path, "plugin.ts")
+          const config = Config.Service.of({
+            entries: () =>
+              Effect.succeed([
+                new Config.Document({
+                  type: "document",
+                  info: decode({ plugins: [plugin] }),
+                }),
+              ]),
+          })
+
+          yield* Effect.promise(() => fs.writeFile(plugin, pluginSource("First source")))
+          yield* ConfigExternalPlugin.Plugin.effect(host).pipe(
+            Effect.provideService(PluginV2.Service, plugins),
+            Effect.provideService(FSUtil.Service, fsUtil),
+            Effect.provideService(Location.Service, location),
+            Effect.provideService(Npm.Service, npm),
+            Effect.provideService(Config.Service, config),
+          )
+          expect((yield* waitForAgent(agents, "hot-reload"))?.description).toBe("First source")
+
+          yield* Effect.promise(() => fs.writeFile(plugin, pluginSource("Second source")))
+          yield* events.publish(ConfigSchema.Event.Updated, {})
+          expect(yield* waitForAgentDescription(agents, "hot-reload", "Second source")).toBe(true)
+        }),
+      ),
+    ),
+  )
 })
 
 const waitForAgent = Effect.fnUntraced(function* (agents: AgentV2.Interface, id: string) {
@@ -250,3 +297,29 @@ const waitForAgent = Effect.fnUntraced(function* (agents: AgentV2.Interface, id:
   }
   return yield* Effect.die(`Timed out waiting for agent ${id}`)
 })
+
+const waitForAgentDescription = Effect.fnUntraced(function* (
+  agents: AgentV2.Interface,
+  id: string,
+  description: string,
+) {
+  for (let attempt = 0; attempt < 100; attempt++) {
+    if ((yield* agents.get(AgentV2.ID.make(id)))?.description === description) return true
+    yield* Effect.sleep("10 millis")
+  }
+  return false
+})
+
+function pluginSource(description: string) {
+  return `export default {
+  id: "source-hot-reload",
+  setup: async (ctx) => {
+    await ctx.agent.transform((agents) => {
+      agents.update("hot-reload", (agent) => {
+        agent.description = ${JSON.stringify(description)}
+        agent.mode = "subagent"
+      })
+    })
+  },
+}`
+}