SERVER-57256: Add deprecation message for count command and direct reader to docs

1 files changed, 37 insertions, 0 deletions

diff --git a/jstests/noPassthrough/deprecated_count.js b/jstests/noPassthrough/deprecated_count.js
new file mode 100644
index 00000000000..aafee4ca749
--- /dev/null
+++ b/jstests/noPassthrough/deprecated_count.js
@@ -0,0 +1,37 @@
+// The count command is deprecated in 5.0.
+//
+// In this test, we run the count command several times.
+// We want to make sure that the deprecation warning message is only logged once despite
+// the multiple invocations in an effort to not clutter the dev's console.
+// More specifically, we expect to only log 1/127 of count() events.
+
+(function() {
+"use strict";
+load("jstests/libs/log.js");  // For findMatchingLogLine, findMatchingLogLines
+
+jsTest.log('Test standalone');
+const standalone = MongoRunner.runMongod({});
+const dbName = 'test';
+const collName = "test_count_command_deprecation_messaging";
+const db = standalone.getDB(dbName);
+const coll = db.getCollection(collName);
+
+coll.drop();
+var res = assert.commandWorked(db.runCommand({count: collName}));
+assert.eq(0, res.n);
+assert.commandWorked(coll.insert({i: 1}));
+res = assert.commandWorked(db.runCommand({count: collName}));
+assert.eq(1, res.n);
+assert.commandWorked(coll.insert({i: 1}));
+res = assert.commandWorked(db.runCommand({count: collName}));
+assert.eq(2, res.n);
+
+const globalLogs = db.adminCommand({getLog: 'global'});
+const fieldMatcher = {
+    msg:
+        "The count command is deprecated. For more information, see https://docs.mongodb.com/manual/reference/method/db.collection.count/"
+};
+const matchingLogLines = [...findMatchingLogLines(globalLogs.log, fieldMatcher)];
+assert.eq(matchingLogLines.length, 1, matchingLogLines);
+MongoRunner.stopMongod(standalone);
+})();