effectify Command service: migrate from Instance.state to Effect service pattern

packages/opencode/specs/effect-migration.md

@@ -132,7 +132,7 @@ Still open and likely worth migrating:
 - [ ] `Worktree`
 - [ ] `Installation`
 - [ ] `Bus`
-- [ ] `Command`
+- [x] `Command`
 - [ ] `Config`
 - [ ] `Session`
 - [ ] `SessionProcessor`

packages/opencode/src/command/index.ts

@@ -1,9 +1,10 @@
 import { BusEvent } from "@/bus/bus-event"
+import { InstanceContext } from "@/effect/instance-context"
+import { runPromiseInstance } from "@/effect/runtime"
 import { SessionID, MessageID } from "@/session/schema"
+import { Effect, Layer, ServiceMap } from "effect"
 import z from "zod"
 import { Config } from "../config/config"
-import { Instance } from "../project/instance"
-import { Identifier } from "../id/id"
 import PROMPT_INITIALIZE from "./template/initialize.txt"
 import PROMPT_REVIEW from "./template/review.txt"
 import { MCP } from "../mcp"
@@ -57,95 +58,119 @@ export namespace Command {
     REVIEW: "review",
   } as const
 
-  const state = Instance.state(async () => {
-    const cfg = await Config.get()
+  export interface Interface {
+    readonly get: (name: string) => Effect.Effect<Info | undefined>
+    readonly list: () => Effect.Effect<Info[]>
+  }
 
-    const result: Record<string, Info> = {
-      [Default.INIT]: {
-        name: Default.INIT,
-        description: "create/update AGENTS.md",
-        source: "command",
-        get template() {
-          return PROMPT_INITIALIZE.replace("${path}", Instance.worktree)
-        },
-        hints: hints(PROMPT_INITIALIZE),
-      },
-      [Default.REVIEW]: {
-        name: Default.REVIEW,
-        description: "review changes [commit|branch|pr], defaults to uncommitted",
-        source: "command",
-        get template() {
-          return PROMPT_REVIEW.replace("${path}", Instance.worktree)
-        },
-        subtask: true,
-        hints: hints(PROMPT_REVIEW),
-      },
-    }
+  export class Service extends ServiceMap.Service<Service, Interface>()("@opencode/Command") {}
 
-    for (const [name, command] of Object.entries(cfg.command ?? {})) {
-      result[name] = {
-        name,
-        agent: command.agent,
-        model: command.model,
-        description: command.description,
-        source: "command",
-        get template() {
-          return command.template
-        },
-        subtask: command.subtask,
-        hints: hints(command.template),
-      }
-    }
-    for (const [name, prompt] of Object.entries(await MCP.prompts())) {
-      result[name] = {
-        name,
-        source: "mcp",
-        description: prompt.description,
-        get template() {
-          // since a getter can't be async we need to manually return a promise here
-          return new Promise<string>(async (resolve, reject) => {
-            const template = await MCP.getPrompt(
-              prompt.client,
-              prompt.name,
-              prompt.arguments
-                ? // substitute each argument with $1, $2, etc.
-                  Object.fromEntries(prompt.arguments?.map((argument, i) => [argument.name, `$${i + 1}`]))
-                : {},
-            ).catch(reject)
-            resolve(
-              template?.messages
-                .map((message) => (message.content.type === "text" ? message.content.text : ""))
-                .join("\n") || "",
-            )
-          })
-        },
-        hints: prompt.arguments?.map((_, i) => `$${i + 1}`) ?? [],
-      }
-    }
+  export const layer = Layer.effect(
+    Service,
+    Effect.gen(function* () {
+      const instance = yield* InstanceContext
 
-    // Add skills as invokable commands
-    for (const skill of await Skill.all()) {
-      // Skip if a command with this name already exists
-      if (result[skill.name]) continue
-      result[skill.name] = {
-        name: skill.name,
-        description: skill.description,
-        source: "skill",
-        get template() {
-          return skill.content
-        },
-        hints: [],
-      }
-    }
+      const commands = yield* Effect.promise(async () => {
+        const cfg = await Config.get()
 
-    return result
-  })
+        const result: Record<string, Info> = {
+          [Default.INIT]: {
+            name: Default.INIT,
+            description: "create/update AGENTS.md",
+            source: "command",
+            get template() {
+              return PROMPT_INITIALIZE.replace("${path}", instance.worktree)
+            },
+            hints: hints(PROMPT_INITIALIZE),
+          },
+          [Default.REVIEW]: {
+            name: Default.REVIEW,
+            description: "review changes [commit|branch|pr], defaults to uncommitted",
+            source: "command",
+            get template() {
+              return PROMPT_REVIEW.replace("${path}", instance.worktree)
+            },
+            subtask: true,
+            hints: hints(PROMPT_REVIEW),
+          },
+        }
+
+        for (const [name, command] of Object.entries(cfg.command ?? {})) {
+          result[name] = {
+            name,
+            agent: command.agent,
+            model: command.model,
+            description: command.description,
+            source: "command",
+            get template() {
+              return command.template
+            },
+            subtask: command.subtask,
+            hints: hints(command.template),
+          }
+        }
+        for (const [name, prompt] of Object.entries(await MCP.prompts())) {
+          result[name] = {
+            name,
+            source: "mcp",
+            description: prompt.description,
+            get template() {
+              // since a getter can't be async we need to manually return a promise here
+              return new Promise<string>(async (resolve, reject) => {
+                const template = await MCP.getPrompt(
+                  prompt.client,
+                  prompt.name,
+                  prompt.arguments
+                    ? // substitute each argument with $1, $2, etc.
+                      Object.fromEntries(prompt.arguments?.map((argument, i) => [argument.name, `$${i + 1}`]))
+                    : {},
+                ).catch(reject)
+                resolve(
+                  template?.messages
+                    .map((message) => (message.content.type === "text" ? message.content.text : ""))
+                    .join("\n") || "",
+                )
+              })
+            },
+            hints: prompt.arguments?.map((_, i) => `$${i + 1}`) ?? [],
+          }
+        }
+
+        // Add skills as invokable commands
+        for (const skill of await Skill.all()) {
+          // Skip if a command with this name already exists
+          if (result[skill.name]) continue
+          result[skill.name] = {
+            name: skill.name,
+            description: skill.description,
+            source: "skill",
+            get template() {
+              return skill.content
+            },
+            hints: [],
+          }
+        }
+
+        return result
+      })
+
+      const get = Effect.fn("Command.get")(function* (name: string) {
+        return commands[name]
+      })
+
+      const list = Effect.fn("Command.list")(function* () {
+        return Object.values(commands)
+      })
+
+      return Service.of({ get, list })
+    }),
+  )
 
   export async function get(name: string) {
-    return state().then((x) => x[name])
+    return runPromiseInstance(Service.use((svc) => svc.get(name)))
   }
 
   export async function list() {
-    return state().then((x) => Object.values(x))
+    return runPromiseInstance(Service.use((svc) => svc.list()))
   }
 }

packages/opencode/src/effect/instances.ts

@@ -1,4 +1,5 @@
 import { Effect, Layer, LayerMap, ServiceMap } from "effect"
+import { Command } from "@/command"
 import { File } from "@/file"
 import { FileTime } from "@/file/time"
 import { FileWatcher } from "@/file/watcher"
@@ -16,6 +17,7 @@ import { registerDisposer } from "./instance-registry"
 export { InstanceContext } from "./instance-context"
 
 export type InstanceServices =
+  | Command.Service
   | Question.Service
   | PermissionNext.Service
   | ProviderAuth.Service
@@ -36,6 +38,7 @@ export type InstanceServices =
 function lookup(_key: string) {
   const ctx = Layer.sync(InstanceContext, () => InstanceContext.of(Instance.current))
   return Layer.mergeAll(
+    Layer.fresh(Command.layer),
     Layer.fresh(Question.layer),
     Layer.fresh(PermissionNext.layer),
     Layer.fresh(ProviderAuth.defaultLayer),