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

packages/opencode/src/tool/read.ts

@@ -5,9 +5,9 @@ import { Tool } from "./tool"
 import { LSP } from "../lsp"
 import { FileTime } from "../file/time"
 import DESCRIPTION from "./read.txt"
-import { Filesystem } from "../util/filesystem"
 import { Instance } from "../project/instance"
 import { Identifier } from "../id/id"
+import { assertExternalDirectory } from "./external-directory"
 
 const DEFAULT_READ_LIMIT = 2000
 const MAX_LINE_LENGTH = 2000
@@ -27,18 +27,9 @@ export const ReadTool = Tool.define("read", {
     }
     const title = path.relative(Instance.worktree, filepath)
 
-    if (!ctx.extra?.["bypassCwdCheck"] && !Filesystem.contains(Instance.directory, filepath)) {
-      const parentDir = path.dirname(filepath)
-      await ctx.ask({
-        permission: "external_directory",
-        patterns: [parentDir],
-        always: [parentDir + "/*"],
-        metadata: {
-          filepath,
-          parentDir,
-        },
-      })
-    }
+    await assertExternalDirectory(ctx, filepath, {
+      bypass: Boolean(ctx.extra?.["bypassCwdCheck"]),
+    })
 
     await ctx.ask({
       permission: "read",