core: extract external directory validation to shared utility to reduce code duplication across tools

packages/opencode/src/tool/edit.ts

@@ -15,6 +15,7 @@ import { FileTime } from "../file/time"
 import { Filesystem } from "../util/filesystem"
 import { Instance } from "../project/instance"
 import { Snapshot } from "@/snapshot"
+import { assertExternalDirectory } from "./external-directory"
 
 const MAX_DIAGNOSTICS_PER_FILE = 20
 
@@ -40,18 +41,7 @@ export const EditTool = Tool.define("edit", {
     }
 
     const filePath = path.isAbsolute(params.filePath) ? params.filePath : path.join(Instance.directory, params.filePath)
-    if (!Filesystem.contains(Instance.directory, filePath)) {
-      const parentDir = path.dirname(filePath)
-      await ctx.ask({
-        permission: "external_directory",
-        patterns: [parentDir, path.join(parentDir, "*")],
-        always: [parentDir + "/*"],
-        metadata: {
-          filepath: filePath,
-          parentDir,
-        },
-      })
-    }
+    await assertExternalDirectory(ctx, filePath)
 
     let diff = ""
     let contentOld = ""