check-permissions: use inflight to eliminate duplicate checks of the same resource

PR-URL: https://github.com/npm/npm/pull/8974
Fixes: https://github.com/npm/npm/issues/8701

This was breaking things on windows due to locking around the files being
created and removed.

1 files changed, 88 insertions, 0 deletions

diff --git a/test/tap/check-permissions.js b/test/tap/check-permissions.js
new file mode 100644
index 000000000..d3c0c6da2
--- /dev/null
+++ b/test/tap/check-permissions.js
@@ -0,0 +1,88 @@
+'use strict'
+var fs = require('fs')
+var path = require('path')
+var test = require('tap').test
+var rimraf = require('rimraf')
+var writable = require('../../lib/install/writable.js').fsAccessImplementation
+var writableFallback = require('../../lib/install/writable.js').fsOpenImplementation
+var exists = require('../../lib/install/exists.js').fsAccessImplementation
+var existsFallback = require('../../lib/install/exists.js').fsStatImplementation
+
+var testBase = path.resolve(__dirname, 'check-permissions')
+var existingDir = path.resolve(testBase, 'exists')
+var nonExistingDir = path.resolve(testBase, 'does-not-exist')
+var writableDir = path.resolve(testBase, 'writable')
+var nonWritableDir = path.resolve(testBase, 'non-writable')
+
+test('setup', function (t) {
+  cleanup()
+  setup()
+  t.end()
+})
+
+test('exists', function (t) {
+  t.plan(2)
+  // fs.access first introduced in node 0.12 / io.js
+  if (fs.access) {
+    existsTests(t, exists)
+  } else {
+    t.pass('# skip fs.access not available in this version')
+    t.pass('# skip fs.access not available in this version')
+  }
+})
+
+test('exists-fallback', function (t) {
+  t.plan(2)
+  existsTests(t, existsFallback)
+})
+
+test('writable', function (t) {
+  t.plan(2)
+  // fs.access first introduced in node 0.12 / io.js
+  if (fs.access) {
+    writableTests(t, writable)
+  } else {
+    t.pass('# skip fs.access not available in this version')
+    t.pass('# skip fs.access not available in this version')
+  }
+})
+
+test('writable-fallback', function (t) {
+  t.plan(2)
+  writableTests(t, writableFallback)
+})
+
+test('cleanup', function (t) {
+  cleanup()
+  t.end()
+})
+
+function setup () {
+  fs.mkdirSync(testBase)
+  fs.mkdirSync(existingDir)
+  fs.mkdirSync(writableDir)
+  fs.mkdirSync(nonWritableDir)
+  fs.chmodSync(nonWritableDir, '555')
+}
+
+function existsTests (t, exists) {
+  exists(existingDir, function (er) {
+    t.error(er, 'exists dir is exists')
+  })
+  exists(nonExistingDir, function (er) {
+    t.ok(er, 'non-existing dir resulted in an error')
+  })
+}
+
+function writableTests (t, writable) {
+  writable(writableDir, function (er) {
+    t.error(er, 'writable dir is writable')
+  })
+  writable(nonWritableDir, function (er) {
+    t.ok(er, 'non-writable dir resulted in an error')
+  })
+}
+
+function cleanup () {
+  rimraf.sync(testBase)
+}