From b76805e5408cfa2e7fcb4ded673ed8aaee9a5dc1 Mon Sep 17 00:00:00 2001
From: Juri Leino <github@line-o.de>
Date: Tue, 25 Oct 2022 18:13:59 +0200
Subject: [PATCH] feat: add method to check for collections

- calls XML-RPC method 'hasCollection'
- add positive and negative test as well as one to test the behaviour
  for users with insufficient access rights
---
 components/collections.js |  6 ++++++
 spec/tests/collections.js | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 41 insertions(+)

diff --git a/components/collections.js b/components/collections.js
index a574be2..f21094f 100644
--- a/components/collections.js
+++ b/components/collections.js
@@ -18,6 +18,11 @@ function read (client, name) {
   return client.promisedMethodCall('getCollectionDesc', [name])
 }
 
+// collection exists?
+function exists (client, name) {
+  return client.promisedMethodCall('hasCollection', [name])
+}
+
 // convenience function
 // throws an exception if and only if
 // the collection exists but cannot be written by the user
@@ -30,5 +35,6 @@ module.exports = {
   remove,
   describe,
   read,
+  exists,
   existsAndCanOpen
 }
diff --git a/spec/tests/collections.js b/spec/tests/collections.js
index f2c8803..7c226cf 100644
--- a/spec/tests/collections.js
+++ b/spec/tests/collections.js
@@ -6,6 +6,41 @@ const asGuest = Object.assign({},
   { basic_auth: { user: 'guest', pass: 'guest' } }
 )
 
+test('collections.exists', function (t) {
+  const db = connect(envOptions)
+
+  t.test('true for existing collection', async function (st) {
+    try {
+      const result = await db.collections.exists('/db')
+      st.true(result, '/db exists')
+    } catch (e) {
+      st.fail(e)
+    }
+  })
+
+  test('false for non-existing collection', async function (st) {
+    try {
+      const result = await db.collections.exists('/foo')
+      st.false(result, '/foo does not exist')
+    } catch (e) {
+      t.fail(e)
+    }
+  })
+
+  test('throws with insufficient access', async function (st) {
+    try {
+      const dbAsGuest = connect()
+      const result = await dbAsGuest.collections.exists('/db/system/security')
+      st.false(result, 'Guest should not see /db/system/security')
+    } catch (e) {
+      // Guest should not see /db/system/security
+      // because it throws with a PermissionDeniedException
+      // it is obvious the collection exists
+      t.ok(e)
+    }
+  })
+})
+
 test('get collection info', function (t) {
   const db = connect(envOptions)
   db.collections.describe('/db')