feat(mongodb): support estimatedDocumentCount, db.stats, db.serverStatus

packages/app-tests/mongoCompletion.test.ts

@@ -134,8 +134,8 @@ test("prioritizes common read helpers and keeps destructive helpers last", () =>
   const getCollectionMethodLabels = labels('db.getCollection("order-events").');
 
   assert.deepEqual(labels("").slice(0, 5), ["db.collection.find", "db.collection.aggregate", "db.getCollection", "use", "db.version"]);
-  assert.deepEqual(methodLabels.slice(0, 5), ["find", "findOne", "aggregate", "countDocuments", "distinct"]);
-  assert.deepEqual(getCollectionMethodLabels.slice(0, 5), ["find", "findOne", "aggregate", "countDocuments", "distinct"]);
+  assert.deepEqual(methodLabels.slice(0, 6), ["find", "findOne", "aggregate", "countDocuments", "estimatedDocumentCount", "distinct"]);
+  assert.deepEqual(getCollectionMethodLabels.slice(0, 6), ["find", "findOne", "aggregate", "countDocuments", "estimatedDocumentCount", "distinct"]);
   assert.deepEqual(methodLabels.slice(-3), ["dropIndex", "dropIndexes", "drop"]);
   assert.deepEqual(labels("db.users.find({})."), ["limit", "sort", "skip", "count"]);
 });
@@ -248,6 +248,14 @@ test("treats $in, $nin and $all elements as values rather than sub-filters", ()
   assert.equal(labels("db.users.find({ $or: [{ ").includes("$oid"), false);
 });
 
+test("offers the newly supported count and database commands", () => {
+  assert.ok(labels("db.users.estim", { fields }).includes("estimatedDocumentCount"));
+  const dbLevel = labels("db.");
+  assert.ok(dbLevel.includes("stats"));
+  assert.ok(dbLevel.includes("serverStatus"));
+  assert.ok(labels("").includes("db.stats"));
+});
+
 test("offers the newer shell value constructors", () => {
   const labels = buildMongoCompletionItems("db.users.find({ _id: ", "db.users.find({ _id: ".length, { fields }).map((item) => item.label);
   for (const constructor of ["NumberInt", "NumberDecimal", "UUID", "BinData", "Timestamp", "MinKey", "MaxKey"]) {
@@ -491,8 +499,9 @@ test("suggests only helpers the shell parser accepts", () => {
   assert.ok(methodLabels.includes("count"));
   assert.ok(methodLabels.includes("drop"));
   assert.ok(methodLabels.includes("distinct"));
+  assert.ok(methodLabels.includes("estimatedDocumentCount"));
   // Suggesting a helper DBX cannot run just hands the user a command that fails.
-  for (const unsupported of ["bulkWrite", "estimatedDocumentCount", "replaceOne"]) {
+  for (const unsupported of ["bulkWrite", "replaceOne", "renameCollection"]) {
     assert.equal(methodLabels.includes(unsupported), false, `${unsupported} is not executable`);
   }
   // Cursor methods are not collection methods.

packages/app-tests/mongoShellCommand.test.ts

@@ -1161,6 +1161,35 @@ test("parseMongoAggregateCommand rejects non-array pipelines and invalid options
   assert.equal(parseMongoAggregateCommand("db.products.aggregate([], {}, true)"), null);
 });
 
+test("parseMongoCountDocumentsCommand reads estimatedDocumentCount as a metadata-backed count", () => {
+  // The driver already takes the metadata fast path for a filterless legacy count().
+  const expected = { collection: "orders", filter: "{}", mode: "legacy" };
+  for (const source of ["db.orders.estimatedDocumentCount()", 'db["orders"].estimatedDocumentCount()', "db.getCollection('orders').estimatedDocumentCount();"]) {
+    assert.deepEqual(parseMongoCountDocumentsCommand(source), expected, source);
+  }
+
+  assert.equal(parseMongoCountDocumentsCommand("db.orders.estimatedDocumentCount({a: 1})"), null);
+  assert.equal(parseMongoCountDocumentsCommand("db.orders.estimatedDocumentCount().limit(5)"), null);
+  // count() and countDocuments() keep their own modes.
+  assert.equal(parseMongoCountDocumentsCommand("db.orders.countDocuments({})")?.mode, "accurate");
+  assert.equal(parseMongoCountDocumentsCommand("db.orders.count()")?.mode, "legacy");
+});
+
+test("parseMongoRunCommand reads db.stats() and db.serverStatus() as run commands", () => {
+  assert.deepEqual(parseMongoRunCommand("db.stats()"), { commandJson: '{"dbStats":1}' });
+  assert.deepEqual(parseMongoRunCommand("db . serverStatus ( ) ;"), { commandJson: '{"serverStatus":1}' });
+  assert.deepEqual(parseMongoRunCommand("DB.STATS()"), { commandJson: '{"dbStats":1}' });
+
+  for (const source of ["db.stats(1)", "db.serverStatus({})"]) {
+    assert.equal(parseMongoRunCommand(source), null, source);
+    assert.match(describeMongoCommandParseFailure(source), /takes no arguments|expects no arguments/, source);
+  }
+
+  // db.collection.stats() is still collection stats, not a run command.
+  assert.equal(parseMongoRunCommand("db.orders.stats()"), null);
+  assert.equal(parseMongoCommand("db.orders.stats()")?.command.kind, "collectionStats");
+});
+
 test("describeMongoCommandParseFailure names an unsupported value constructor and where it is", () => {
   const message = describeMongoCommandParseFailure('db.reports.updateOne({a: 1}, {$set: {t: Foo("x")}}, {upsert: true})');
   assert.match(message, /Unsupported value Foo\(\.\.\.\) in the update argument of updateOne\(\)/);
@@ -1187,7 +1216,7 @@ test("describeMongoCommandParseFailure names unsupported methods and points at a
   assert.match(describeMongoCommandParseFailure('db["my-coll"].renameCollection("x")'), /renameCollection\(\) is not supported/);
   assert.match(describeMongoCommandParseFailure('db.getCollection("my-coll").watch()'), /watch\(\) is not supported/);
 
-  assert.match(describeMongoCommandParseFailure("db.stats()"), /db\.stats\(\) is not supported; use db\.runCommand\(\{ dbStats: 1 \}\)/);
+  assert.match(describeMongoCommandParseFailure('db.createCollection("c")'), /db\.createCollection\(\) is not supported; collections are created on first insert/);
   assert.match(describeMongoCommandParseFailure('db.getSiblingDB("other").c.find({})'), /use <database>/);
   assert.match(describeMongoCommandParseFailure("db.adminCommand({ping: 1})"), /use db\.runCommand/);
   assert.match(describeMongoCommandParseFailure("show collections"), /listed in the sidebar/);