install: Ensure walking the tree doesn't result in infinite loops

Fixes: #9223
PR-URL: https://github.com/npm/npm/pull/9261

1 files changed, 61 insertions, 0 deletions

diff --git a/test/tap/symlink-cycle.js b/test/tap/symlink-cycle.js
new file mode 100644
index 000000000..b09b25acc
--- /dev/null
+++ b/test/tap/symlink-cycle.js
@@ -0,0 +1,61 @@
+'use strict'
+var fs = require('fs')
+var path = require('path')
+var test = require('tap').test
+var mkdirp = require('mkdirp')
+var osenv = require('osenv')
+var rimraf = require('rimraf')
+var writeFileSync = require('fs').writeFileSync
+var common = require('../common-tap.js')
+
+var base = path.join(__dirname, path.basename(__filename, '.js'))
+var cycle = path.join(base, 'cycle')
+
+var cycleJSON = {
+  name: 'cycle',
+  version: '1.0.0',
+  description: '',
+  main: 'index.js',
+  scripts: {
+    test: 'echo \"Error: no test specified\" && exit 1'
+  },
+  dependencies: {
+    'cycle': '*'
+  },
+  author: '',
+  license: 'ISC'
+}
+
+test('setup', function (t) {
+  setup()
+  t.end()
+})
+
+test('ls', function (t) {
+  process.chdir(cycle)
+  common.npm(['ls'], {}, function (err, code, stdout, stderr) {
+    t.ifError(err, 'installed w/o error')
+    t.is(stderr, '', 'no warnings printed to stderr')
+    t.end()
+  })
+})
+
+test('cleanup', function (t) {
+  process.chdir(osenv.tmpdir())
+  cleanup()
+  t.end()
+})
+
+function cleanup () {
+  rimraf.sync(base)
+}
+
+function setup () {
+  cleanup()
+  mkdirp.sync(path.join(cycle, 'node_modules'))
+  writeFileSync(
+    path.join(cycle, 'package.json'),
+    JSON.stringify(cycleJSON, null, 2)
+  )
+  fs.symlinkSync(cycle, path.join(cycle, 'node_modules', 'cycle'))
+}