SERVER-21168 Update top on database drop

1 files changed, 35 insertions, 0 deletions

diff --git a/jstests/noPassthroughWithMongod/top_drop.js b/jstests/noPassthroughWithMongod/top_drop.js
new file mode 100644
index 00000000000..e31129b4a4d
--- /dev/null
+++ b/jstests/noPassthroughWithMongod/top_drop.js
@@ -0,0 +1,35 @@
+/**
+ * Checks that top removes entries after dropping a collection or database.
+ * TODO(SERVER-21167): Move this test from noPassthrough to core.
+ */
+(function() {
+    let topDB = db.getSiblingDB("topdrop");
+    assert.commandWorked(topDB.dropDatabase());
+
+    // Asserts that the output of top contains exactly these collection entries for topDB.
+    function checkTopEntries(expectedEntries) {
+        let res = topDB.adminCommand("top");
+        assert.commandWorked(res);
+        let namesFromTotals = Object.keys(res.totals).filter(function(ns) {
+            return ns.startsWith(topDB.getName() + ".");
+        });
+        let expectedEntryNames = expectedEntries.map(function(coll) {
+            return coll.getFullName();
+        });
+        assert.eq(namesFromTotals.sort(), expectedEntryNames.sort());
+    }
+
+    // Create a few entries in top.
+    assert.writeOK(topDB.coll1.insert({}));
+    assert.writeOK(topDB.coll2.insert({}));
+    assert.writeOK(topDB.coll3.insert({}));
+    checkTopEntries([topDB.coll1, topDB.coll2, topDB.coll3]);
+
+    // Check that dropping a collection removes that collection but leaves the others.
+    assert.commandWorked(topDB.runCommand({drop: "coll3"}));
+    checkTopEntries([topDB.coll1, topDB.coll2]);
+
+    // Check that dropping the database removes the remaining collections.
+    assert.commandWorked(topDB.dropDatabase());
+    checkTopEntries([]);
+}());