chore(node-sdk): audit plugins shared

Add plugins/common.ts for the helpers and size limits copied across plugin files; managed-transaction compares snapshots in one place; guard template imported directly.

Claude-Session: https://claude.ai/code/session_01Agoc9bRVE9KL7mmWtey9Vq

src/cli.ts

@@ -13,7 +13,8 @@ import {
 import { writePrivateFile } from './secure-files.js';
 import { SUPPORTED_AGENTS } from './plugins/registry.js';
 import type { AgentPlugin, InstallConfig } from './plugins/base.js';
-import { generateHookScript, generateGuardScript } from './plugins/hook-template.js';
+import { generateGuardScript } from './plugins/guard-template.js';
+import { generateHookScript } from './plugins/hook-template.js';
 import { augmentPlugin } from './plugins/augment.js';
 import { claudecodePlugin } from './plugins/claudecode.js';
 import { cursorPlugin } from './plugins/cursor.js';

src/plugins/common.ts

@@ -0,0 +1,31 @@
+import path from 'node:path';
+
+export const MAX_SECRET_BYTES = 64 * 1024;
+export const MAX_CONFIG_BYTES = 512 * 1024;
+export const MAX_SOURCE_BYTES = 2 * 1024 * 1024;
+
+export function asError(error: unknown): Error {
+  return error instanceof Error ? error : new Error(String(error));
+}
+
+export function errorMessage(error: unknown): string {
+  return error instanceof Error ? error.message : String(error);
+}
+
+export function hasCode(error: unknown, code: string): boolean {
+  return typeof error === 'object' && error !== null && 'code' in error && error.code === code;
+}
+
+export function samePath(left: string, right: string): boolean {
+  const normalizedLeft = path.resolve(left);
+  const normalizedRight = path.resolve(right);
+  return process.platform === 'win32'
+    ? normalizedLeft.toLowerCase() === normalizedRight.toLowerCase()
+    : normalizedLeft === normalizedRight;
+}
+
+export function sameAgentId(left: unknown, right: string): boolean {
+  return typeof left === 'string' && (process.platform === 'win32'
+    ? left.toLowerCase() === right.toLowerCase()
+    : left === right);
+}

src/plugins/hook-template.ts

@@ -1,8 +1,5 @@
 import { PROTECTED_RUNTIME_READER } from './runtime-reader-template.js';
 
-export { generateGuardScript } from './guard-template.js';
-export type { GuardScriptOptions } from './guard-template.js';
-
 export interface HookScriptOptions {
   readonly failClosed?: boolean;
   readonly nativePayload?: boolean;

src/plugins/managed-files.ts

@@ -1,8 +1,7 @@
 import { constants } from 'node:fs';
 import fsp from 'node:fs/promises';
 import type { FileHandle } from 'node:fs/promises';
-
-const MAX_SOURCE_BYTES = 2 * 1024 * 1024;
+import { asError, errorMessage, hasCode, MAX_SOURCE_BYTES } from './common.js';
 
 export interface FileSnapshot {
   readonly contents: string;
@@ -11,18 +10,6 @@ export interface FileSnapshot {
   readonly mode: number;
 }
 
-function asError(error: unknown): Error {
-  return error instanceof Error ? error : new Error(String(error));
-}
-
-function errorMessage(error: unknown): string {
-  return error instanceof Error ? error.message : String(error);
-}
-
-function hasCode(error: unknown, code: string): boolean {
-  return typeof error === 'object' && error !== null && 'code' in error && error.code === code;
-}
-
 export async function readPhysicalFile(
   filePath: string,
   label: string,

src/plugins/managed-installation.ts

@@ -2,6 +2,7 @@ import os from 'node:os';
 import path from 'node:path';
 import { ensurePrivateDirectory, resolvePrivateChildDirectory } from '../runtime-paths.js';
 import type { InstallConfig } from './base.js';
+import { MAX_CONFIG_BYTES, MAX_SECRET_BYTES, sameAgentId, samePath } from './common.js';
 import { generateGuardScript, type GuardScriptOptions } from './guard-template.js';
 import { generateHookScript, type HookScriptOptions } from './hook-template.js';
 import {
@@ -19,9 +20,6 @@ import {
 } from './managed-transaction.js';
 import { parseStrictJsonObject } from './strict-json.js';
 
-const MAX_SECRET_BYTES = 64 * 1024;
-const MAX_CONFIG_BYTES = 512 * 1024;
-
 export interface ManagedRuntimePaths {
   readonly runtimeRoot: string;
   readonly agentDirectory: string;
@@ -79,14 +77,6 @@ interface RuntimeArtifactLocation {
 
 export type { RenameFile };
 
-export function samePath(left: string, right: string): boolean {
-  const normalizedLeft = path.resolve(left);
-  const normalizedRight = path.resolve(right);
-  return process.platform === 'win32'
-    ? normalizedLeft.toLowerCase() === normalizedRight.toLowerCase()
-    : normalizedLeft === normalizedRight;
-}
-
 function validateInstallConfig(config: InstallConfig, agentKey: string): void {
   for (const [field, value] of [
     ['agentName', config.agentName],
@@ -146,12 +136,6 @@ export function managedRuntimePaths(
   };
 }
 
-function sameAgentId(left: unknown, right: string): boolean {
-  return typeof left === 'string' && (process.platform === 'win32'
-    ? left.toLowerCase() === right.toLowerCase()
-    : left === right);
-}
-
 async function validateRuntimeIdentity(
   paths: ManagedRuntimePaths,
   agentKey: string,

src/plugins/managed-runtime-status.ts

@@ -2,12 +2,10 @@ import os from 'node:os';
 import path from 'node:path';
 import { generateGuardScript, type GuardScriptOptions } from './guard-template.js';
 import { generateHookScript, type HookScriptOptions } from './hook-template.js';
+import { MAX_CONFIG_BYTES, MAX_SECRET_BYTES, sameAgentId, samePath } from './common.js';
 import { inspectPhysicalDirectory, readPhysicalFile } from './managed-files.js';
-import { samePath } from './managed-installation.js';
 import { parseStrictJsonObject, type JsonObject } from './strict-json.js';
 
-const MAX_SECRET_BYTES = 64 * 1024;
-const MAX_CONFIG_BYTES = 512 * 1024;
 const GUARD_SCRIPT = 'guard.js';
 const AUDIT_SCRIPT = 'hook.js';
 
@@ -22,10 +20,6 @@ export interface ManagedRuntimeStatusOptions {
   readonly auditOptions?: HookScriptOptions;
 }
 
-function sameAgentId(left: string, right: string): boolean {
-  return process.platform === 'win32' ? left.toLowerCase() === right.toLowerCase() : left === right;
-}
-
 function requireString(value: unknown, field: string, configPath: string): string {
   if (typeof value !== 'string' || value.trim().length === 0) {
     throw new Error(`Elydora runtime config ${field} is invalid: ${configPath}`);

src/plugins/managed-transaction.ts

@@ -2,14 +2,13 @@ import { randomUUID } from 'node:crypto';
 import fsp from 'node:fs/promises';
 import type { FileHandle } from 'node:fs/promises';
 import path from 'node:path';
+import { asError, errorMessage, hasCode, MAX_SOURCE_BYTES } from './common.js';
 import {
   inspectPhysicalDirectory,
   readPhysicalFile,
   type FileSnapshot,
 } from './managed-files.js';
 
-const MAX_SOURCE_BYTES = 2 * 1024 * 1024;
-
 export interface ManagedChangeSpec {
   readonly filePath: string;
   readonly label: string;
@@ -60,18 +59,6 @@ interface StagedChange {
 
 export type RenameFile = (source: string, destination: string) => Promise<void>;
 
-function asError(error: unknown): Error {
-  return error instanceof Error ? error : new Error(String(error));
-}
-
-function errorMessage(error: unknown): string {
-  return error instanceof Error ? error.message : String(error);
-}
-
-function hasCode(error: unknown, code: string): boolean {
-  return typeof error === 'object' && error !== null && 'code' in error && error.code === code;
-}
-
 function targetKey(filePath: string): string {
   const resolved = path.resolve(filePath);
   return process.platform === 'win32' ? resolved.toLowerCase() : resolved;
@@ -113,16 +100,20 @@ export async function prepareManagedFileChange(
   };
 }
 
-async function assertUnchanged(change: ManagedFileChange, operationName: string): Promise<void> {
-  const current = await readPhysicalFile(change.filePath, change.label, change.maximumBytes);
-  if ((!current && change.original)
-    || (current && !change.original)
-    || (current && change.original && (
-      current.contents !== change.original.contents
-      || current.device !== change.original.device
-      || current.inode !== change.original.inode
-    ))) {
-    throw new Error(`${change.label} changed during ${operationName}: ${change.filePath}`);
+function sameSnapshot(current: FileSnapshot | undefined, original: FileSnapshot | undefined): boolean {
+  if (!current || !original) return !current && !original;
+  return current.contents === original.contents
+    && current.device === original.device
+    && current.inode === original.inode;
+}
+
+async function assertUnchanged(
+  target: ManagedFilePrecondition,
+  operationName: string,
+): Promise<void> {
+  const current = await readPhysicalFile(target.filePath, target.label, target.maximumBytes);
+  if (!sameSnapshot(current, target.original)) {
+    throw new Error(`${target.label} changed during ${operationName}: ${target.filePath}`);
   }
 }
 
@@ -131,20 +122,7 @@ async function assertPreconditions(
   operationName: string,
 ): Promise<void> {
   for (const condition of transaction.preconditions ?? []) {
-    const current = await readPhysicalFile(
-      condition.filePath,
-      condition.label,
-      condition.maximumBytes,
-    );
-    if ((!current && condition.original)
-      || (current && !condition.original)
-      || (current && condition.original && (
-        current.contents !== condition.original.contents
-        || current.device !== condition.original.device
-        || current.inode !== condition.original.inode
-      ))) {
-      throw new Error(`${condition.label} changed during ${operationName}: ${condition.filePath}`);
-    }
+    await assertUnchanged(condition, operationName);
   }
 }
 
@@ -285,11 +263,7 @@ async function assertCommittedUnchanged(staged: StagedChange): Promise<void> {
     }
     return;
   }
-  const committed = staged.committedSnapshot;
-  if (!current || !committed
-    || current.contents !== committed.contents
-    || current.device !== committed.device
-    || current.inode !== committed.inode) {
+  if (!current || !sameSnapshot(current, staged.committedSnapshot)) {
     throw new Error(
       `${staged.change.label} changed during transaction recovery: ${staged.change.filePath}`,
     );

src/plugins/opencode-contract.ts

@@ -1,7 +1,7 @@
 import os from 'node:os';
 import path from 'node:path';
 import type { HookScriptOptions } from './hook-template.js';
-import { samePath } from './managed-installation.js';
+import { samePath } from './common.js';
 import { parseStrictJsonObject } from './strict-json.js';
 
 export const AGENT_KEY = 'opencode';