feat: lift shell read restrictions and page bash/read tool outputs to 200 lines

test/guard.test.mjs

@@ -1,7 +1,7 @@
 // Guard rules for shell commands, focused on inline interpreter scripts.
 import test from 'node:test'
 import assert from 'node:assert/strict'
-import { shellViolation, inlineScriptViolation } from '../index.js'
+import { shellViolation, inlineScriptViolation, pageText, pageShellResult } from '../index.js'
 
 const ALLOW = [
   // harmless computation one-liners
@@ -25,6 +25,14 @@ const ALLOW = [
   // unrelated commands
   'git status',
   'npm test 2>&1 | tail -5',
+  // reading / searching through the shell is allowed (output is paged by the bash wrapper)
+  'cat README.md',
+  'head -50 index.js',
+  'sed -n 10,20p index.js',
+  'grep -rn foo .',
+  'find . -name "*.js"',
+  'ls -R lib',
+  `awk '{print $1}' f.txt`,
 ]
 
 const BLOCK = [
@@ -61,6 +69,12 @@ const BLOCK = [
   `sudo node -e "require('fs')"`,
   `/usr/bin/node -e "require('fs')"`,
   `ls && node -e "require('fs')"`,
+  // shell writes stay blocked
+  `awk '{print > "out.txt"}' f.txt`,
+  `awk 'BEGIN{system("rm x")}'`,
+  'find . -name "*.tmp" -delete',
+  'sed -i s/a/b/ f.txt',
+  'echo x > f.txt',
 ]
 
 test('harmless inline one-liners and normal commands are allowed', () => {
@@ -76,3 +90,22 @@ test('denial message points at the right tools', () => {
   assert.match(m, /read\/grep\/edit/)
   assert.match(m, /computation-only one-liners are fine/)
 })
+
+test('pageText caps output at pageLines and names the next read', () => {
+  const text = Array.from({ length: 450 }, (_, i) => `l${i + 1}`).join('\n') + '\n'
+  let saved
+  const p = pageText(text, 200, (t) => { saved = t; return '/tmp/x.txt' })
+  assert.equal(saved, text)
+  assert.equal(p.text.split('\n').length, 201)
+  assert.match(p.text, /\[output lines 1-200 of 450\. Read lines 201-400: read file_path="\/tmp\/x\.txt" offset=201/)
+  assert.equal(pageText('a\nb\n', 200, () => { throw new Error('no save') }), null)
+})
+
+test('pageShellResult pages stdout and leaves short streams alone', () => {
+  const long = Array.from({ length: 250 }, (_, i) => String(i)).join('\n')
+  const v = pageShellResult({ kind: 'foreground', stdout: { text: long, truncated: false }, stderr: { text: 'e', truncated: false } }, 200, () => '/tmp/full.txt')
+  assert.equal(v.stdout.spillPath, '/tmp/full.txt')
+  assert.match(v.stdout.text, /stdout lines 1-200 of 250/)
+  assert.equal(v.stderr.text, 'e')
+  assert.deepEqual(pageShellResult({ kind: 'background', jobId: 'j' }, 200), { kind: 'background', jobId: 'j' })
+})