SET documentdb.next_collection_id TO 3000;
SET documentdb.next_collection_index_id TO 3000;

-- null db name
SELECT documentdb_api.find_and_modify(NULL, '{}');

-- null message
SELECT documentdb_api.find_and_modify('db', NULL);

-- missing params
SELECT documentdb_api.find_and_modify('fam', '{}');
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "remove_or_update"}');

-- no such collection, upsert=false
--  i) remove=true
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "dne", "query": {"a": 1000}, "remove": 0.1, "sort": {"b": -1}}');
--  ii) remove=false
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "dne", "query": {"a": 1}, "update": {"_id": 1, "b": 1}, "upsert": false}');

-- no such collection, upsert=true
--  i) query is given
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "create_on_fam_1", "query": {"a": 1}, "update": {"_id": 1, "b": 1}, "upsert": 1.1}');
SELECT document FROM documentdb_api.collection('fam', 'create_on_fam_1') ORDER BY document;
--  ii) query is not given, and the upserted document is requested
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "create_on_fam_2", "update": {"_id": 1, "b": 1}, "upsert": true, "new": -1}');
SELECT document FROM documentdb_api.collection('fam', 'create_on_fam_2') ORDER BY document;
--  iii) enable_create_collection_on_insert is disabled
BEGIN;
  SET LOCAL documentdb.enable_create_collection_on_insert TO OFF;
  SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "create_on_fam_3", "update": {"_id": 1, "b": 1}, "upsert": true}');
ROLLBACK;

-- test conflicting options
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "opts_conflict", "remove": true, "update": {"b": 1}}');
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "opts_conflict", "remove": true, "upsert": true}');
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "opts_conflict", "remove": true, "new": true}');

-- field type validations
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": []}');
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "invalid_type", "query": 1}');
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "invalid_type", "sort": "text"}');
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "invalid_type", "remove": {}}');
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "invalid_type", "update": 1}');
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "invalid_type", "new": []}');
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "invalid_type", "fields": "text"}');
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "invalid_type", "upsert": []}');

-- hard errors for unsupported options
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "not_supported", "arrayFilters": 1}');
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "not_supported", "hint": 1}');

-- unknown option
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "unknown_option", "unknown_option": 1}');

SELECT 1 FROM documentdb_api.insert_one('fam', 'collection', '{"a":5,"b":7}');
SELECT 1 FROM documentdb_api.insert_one('fam', 'collection', '{"a":5,"b":5}');
SELECT 1 FROM documentdb_api.insert_one('fam', 'collection', '{"a":5,"b":6}');

-- Disallow writes to system.views
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "system.views", "query": null, "remove": 0.0, "sort": {"b": -1}, "update": {"a": 10}, "fields": {"_id": 0}}');

BEGIN;
  SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "collection", "query": null, "remove": 0.0, "sort": {"b": -1}, "update": {"a": 10}, "fields": {"_id": 0}}');
  SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "collection", "query": {"a": 5}, "sort": {"b": 1}, "update": 1, "update": {"a": 20}, "fields": {"_id": 0}}');
  SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "collection", "query": {"a": 100}, "sort": {"b": 1}, "update": {"a": 1}, "fields": {"_id": 0, "b": 0}, "upsert": 0, "new": false}');
  SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "collection", "query": {"a": 100}, "sort": "", "sort": {"b": 1}, "update": {"a": 1}, "fields": {"_id": 0, "b": 0}, "upsert": false, "new": true}');
  SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "collection", "query": {"a": 100}, "sort": {"b": 1}, "update": {"_id": 40, "a": 30}, "fields": {"b": 1, "_id": 0}, "upsert": true}');

  -- using update operators / aggregation pipeline --

  -- multiple $inc, so only takes the last one into the account
  SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "collection", "query": {"a": { "$gte": 15 } }, "sort": {"a": 1}, "update": {"$set": {"z": 5}, "$inc": {"z": 5}, "$inc": {"a": 10}}, "upsert": false, "new": true, "fields": {"_id": 0}}');

  -- multiple $set/$inc but provided via a single document, so applies all
  SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "collection", "query": {"a": 1000 }, "update": {"$set": {"_id": 1000, "p": 10, "r": 20}, "$inc": {"s": 30, "t": 40}}, "upsert": true, "new": true, "fields": {"_id": 0}}');

  SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "collection", "query": {"z": { "$exists": false } }, "sort": {"a": 1}, "update": [{"$set": {"a": -10}}, {"$addFields": {"z": 7}}], "upsert": false, "new": true, "fields": {"_id": 0}}');
  SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "collection", "query": {"a": 2000 }, "update": [ {"$set": {"p": 40, "_id": 2000, "r": 50}}, {"$unset": "p"}, {"$set": {"r": 70}}], "new": true, "fields": {"_id": 0}, "upsert": 1}');
ROLLBACK;

BEGIN;
  SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "collection", "query": {"a": 100}, "sort": {"b": 1}, "update": {"_id": 40, "a": [ 30 ]}, "fields": {"b": 1, "_id": 0}, "upsert": true}');
  SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "collection", "query": {"a": 100}, "sort": {"b": 1}, "update": { "$set": { "a.$[a]": 10 }}, "fields": {"b": 1, "_id": 0}, "upsert": true, "arrayFilters": [ { "a": 30 } ]}');
ROLLBACK;

BEGIN;
  SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "collection", "query": {"a": { "$gte": 15 } }, "sort": {}, "update": {"$set": {"z": 5}, "$inc": {"z": 5}, "$inc": {"a": 10}}, "upsert": false, "new": true, "fields": {}}');
ROLLBACK;

BEGIN;
  SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "collection", "query": null, "remove": true, "sort": {"b": -1}, "fields": {"_id": 0, "a": 0}}');
  SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "collection", "query": {"a": 5}, "remove": true, "sort": {"b": 1}, "fields": {"_id": 0, "b": 1}, "upsert": null}');
  SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "collection", "query": {"a": 100}, "remove": true, "sort": {"b": 1}, "fields": {"_id": 0}}');
  SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "collection", "query": {"a": 100}, "remove": true, "sort": {}, "fields": {}}');
ROLLBACK;

-- test a sharded collection
SELECT documentdb_api.create_collection('fam','sharded_collection');
SELECT documentdb_api.shard_collection('fam','sharded_collection', '{"a":"hashed"}', false);

SELECT 1 FROM documentdb_api.insert_one('fam', 'sharded_collection', '{"a": 10,"b":7}');
SELECT 1 FROM documentdb_api.insert_one('fam', 'sharded_collection', '{"a":20,"b":5}');
SELECT 1 FROM documentdb_api.insert_one('fam', 'sharded_collection', '{"a":30,"b":6}');
SELECT 1 FROM documentdb_api.insert_one('fam', 'sharded_collection', '{"b":8}');
SELECT 1 FROM documentdb_api.insert_one('fam', 'sharded_collection', '{"b":9,"a": null}');

-- update the shard key
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "sharded_collection", "query": {"a": 10}, "update": {"$set": {"a": 1000}}, "fields": {"_id": 0}, "new": true}');
-- update a field other than the shard key
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "sharded_collection", "query": {"a": 20}, "update": {"$set": {"b": -1}}, "fields": {"_id": 0}, "new": true}');
-- test upsert
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "sharded_collection", "query": {"a": -1}, "update": {"$set": {"b": -2, "_id": 100}}, "new": true, "upsert": true}');
-- test "null" shard key: i) shard key is really equal to null
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "sharded_collection", "query": {"a": null}, "update": {"$set": {"b": -3}}, "fields": {"_id": 0}, "sort": {"b": -1}, "new": true}');
-- test "null" shard key: ii) shard key is not set
-- should update the document having {"b": 8} even if it doesn't specify "a" field at all
BEGIN;
  SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "sharded_collection", "query": {"a": null}, "update": {"$set": {"b": -4}}, "fields": {"_id": 0}, "sort": {"b": -1}, "new": false}');
ROLLBACK;
-- test "null" shard key: iii) shard key is not set
-- should update the document having {"b": -3}
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "sharded_collection", "query": {"a": null}, "update": {"b": -4}, "fields": {"_id": 0}, "sort": {"b": 1}, "new": false}');

-- missing shard key
--SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "sharded_collection", "query": {"a": { "$gte": 15 } }, "update": {"$set": {"z": 5}}}');
--SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "sharded_collection", "query": null, "update": {"a": 10}}');
--SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "sharded_collection", "query": {"b": -2}, "remove": true}');

SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "sharded_collection", "query": {"b": -2, "a": -1}, "remove": true}');
-- should match the document having {"b": -4} even if it doesn't specify "a" field at all
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "sharded_collection", "query": {"b": -4, "a": null}, "remove": true, "fields": {"_id": 0}}');

-- show that we validate "update" document even if collection doesn't exist or if we can't match any documents
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "dne", "query": {"a": 1}, "update": { "$set": { "a": 1 }, "$unset": {"a": 1 } } }');
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "dne", "query": {"$a": 1}, "update": { "$set": { "a": 1 } } }');
SELECT documentdb_api.create_collection('fam', 'no_match');
\set VERBOSITY TERSE
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "no_match", "update": { "$set": { "a": 1 }, "$unset": {"a": 1 } }}');
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "no_match", "query": {"$a": 1}, "update": { "$set": { "a": 1 } } }');
\set VERBOSITY DEFAULT

-- test retryable update
SELECT 1 FROM documentdb_api.insert_one('fam', 'retryable_update', '{"_id": 1, "a": 1, "b": 1}');
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "retryable_update", "query": {"a": 1}, "update": {"$inc": {"b": 1}}, "new": false}', 'xact-1');
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "retryable_update", "query": {"a": 1}, "update": {"$inc": {"b": 1}}, "new": true}', 'xact-1');
SELECT document FROM documentdb_api.collection('fam', 'retryable_update') ORDER BY document;

-- third call is considered a new try
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "retryable_update", "query": {"a": 1}, "update": {"$inc": {"b": 1}}, "new": true, "fields": {"a": 0}}', 'xact-1');
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "retryable_update", "query": {"a": 1}, "update": {"$inc": {"b": 1}}, "new": true, "fields": {"_id": 0}}', 'xact-1');
SELECT document FROM documentdb_api.collection('fam', 'retryable_update') ORDER BY document;

SELECT documentdb_api.shard_collection('fam','retryable_update', '{"a":"hashed"}', false);

-- test with upsert
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "retryable_update", "query": {"_id": 2, "a": 100}, "update": {"$inc": {"b": 1}}, "new": true, "upsert": true, "fields": {"a": 0}}', 'xact-1');
-- Note that specifying different values for "new"/"fields" fields doesn't
-- have any effect on the response message.
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "retryable_update", "query": {"_id": 2, "a": 100}, "update": {"$inc": {"b": 1}}, "new": false, "upsert": true, "fields": {"b": 0}}', 'xact-1');
SELECT document FROM documentdb_api.collection('fam', 'retryable_update') ORDER BY document;

-- test with upsert, collection gets created automatically
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "retryable_update_dne", "query": {"_id": 2, "a": 100}, "update": {"$inc": {"b": 1}}, "new": false, "upsert": true}', 'xact-2');
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "retryable_update_dne", "query": {"_id": 2, "a": 100}, "update": {"$inc": {"b": 1}}, "new": true, "upsert": true}', 'xact-2');
SELECT document FROM documentdb_api.collection('fam', 'retryable_update_dne') ORDER BY document;

-- test retryable delete
SELECT 1 FROM documentdb_api.insert_one('fam', 'retryable_delete', '{"_id": 1, "a": 1, "b": 1}');
SELECT 1 FROM documentdb_api.insert_one('fam', 'retryable_delete', '{"_id": 2, "a": 1, "b": 1}');
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "retryable_delete", "query": {"a": 1}, "remove": true}', 'xact-11');
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "retryable_delete", "query": {"a": 1}, "remove": true}', 'xact-11');
SELECT document FROM documentdb_api.collection('fam', 'retryable_delete') ORDER BY document;

-- third call is considered a new try
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "retryable_delete", "query": {"a": 1}, "remove": true, "fields": {"b": 0}}', 'xact-11');
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "retryable_delete", "query": {"a": 1}, "remove": true, "fields": {"a": 0}}', 'xact-11');
SELECT document FROM documentdb_api.collection('fam', 'retryable_delete') ORDER BY document;

SELECT 1 FROM documentdb_api.insert_one('fam', 'retryable_delete_sharded', '{"_id": 1, "a": 1, "b": 1}');
SELECT 1 FROM documentdb_api.insert_one('fam', 'retryable_delete_sharded', '{"_id": 2, "a": 1, "b": 1}');

SELECT documentdb_api.shard_collection('fam','retryable_delete_sharded', '{"a":"hashed"}', false);

SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "retryable_delete_sharded", "query": {"a": 1}, "remove": true, "fields": {"b": 0}}', 'xact-14');
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "retryable_delete_sharded", "query": {"a": 1}, "remove": true, "fields": {"a": 0}}', 'xact-14');
SELECT document FROM documentdb_api.collection('fam', 'retryable_delete_sharded') ORDER BY document;

-- third call is considered a new try
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "retryable_delete_sharded", "query": {"a": 1}, "remove": true}', 'xact-14');
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "retryable_delete_sharded", "query": {"a": 1}, "remove": true}', 'xact-14');
SELECT document FROM documentdb_api.collection('fam', 'retryable_delete_sharded') ORDER BY document;

-- test with a query that doesn't match any documents
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "retryable_delete", "query": {"a": 100}, "remove": true}', 'xact-11');
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "retryable_delete", "query": {"a": 100}, "remove": true}', 'xact-11');

-- test with a collection that doesn't exist
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "retryable_delete_dne", "query": {"a": 100}, "remove": true}', 'xact-13');
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "retryable_delete_dne", "query": {"a": 100}, "remove": true}', 'xact-13');

SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "retryable_update", "query": {"a": 1}, "update": {"$inc": {"b": 1}}, "new": true, "fields": {"a": 0}}', 'xact-20');
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "retryable_update", "query": {"a": 1}, "update": {"$inc": {"b": 1}}, "new": true, "fields": {"a": 0}}', 'xact-20');
SELECT document FROM documentdb_api.collection('fam', 'retryable_update') ORDER BY document;

-- unknown operator expressions in fields argument
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "collection", "query": {"_id": 1}, "update": {"$inc": {"b": 1}}, "new": true, "upsert": true, "fields": {"foo": {"$pop": ["bar"]}}}');

-- test with operator expression in fields argument
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "collection", "query": {"_id": 1}, "update": {"$inc": {"b": 1}}, "new": true, "upsert": true, "fields": {"foo": {"$pow": [1, 2]}}}');

-- schema validation
SELECT documentdb_api_catalog.bson_dollar_project(document,'{"_id":0,"a":1,"b":1}') FROM documentdb_api.collection('fam', 'collection') ORDER BY document;
SELECT documentdb_api.coll_mod('fam', 'collection', '{"collMod": "collection", "validator": {"$jsonSchema": {"bsonType": "object", "properties": {"a": {"bsonType": "int"}}}}}');
-- expect to fail since "a" is not an int
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "collection", "query": {"_id": 1}, "update": {"$set": {"a": "hello"}}, "new": true, "upsert": true, "fields": {"foo": {"$pow": [1, 2]}}}');
-- expect to succeed, upsert
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "collection", "query": {"_id": 2}, "update": {"$set": {"a": 200}}, "new": true, "upsert": true, "fields": {"foo": {"$pow": [1, 2]}}}');
-- expect to succeed, update
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "collection", "query": {"_id": 1}, "update": {"$set": {"a": 10}}, "new": true, "upsert": true, "fields": {"foo": {"$pow": [1, 2]}}}');
select documentdb_api.coll_mod('fam', 'collection', '{"collMod": "collection", "validationLevel": "moderate", "validationAction": "warn"}');
select documentdb_api.insert_one('fam', 'collection', '{"_id": 3, "a": "hello", "b": 11}');
select documentdb_api.coll_mod('fam', 'collection', '{"collMod": "collection", "validationAction": "error"}');
-- expect to succeed, validationLevel=moderate
select documentdb_api.find_and_modify('fam', '{"findAndModify": "collection", "query": {"_id": 3}, "update": {"$set": {"a": "test"}}, "new": true, "upsert": true, "fields": {"foo": {"$pow": [1, 2]}}}');
SELECT documentdb_api_catalog.bson_dollar_project(document,'{"_id":0,"a":1,"b":1}') FROM documentdb_api.collection('fam', 'collection') ORDER BY document;

-- shard collection
SELECT documentdb_api.shard_collection('fam','collection', '{"_id":"hashed"}', false);
SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "collection", "query": {"_id": 3}, "update": {"$set": {"a": "plus"}}, "new": true, "upsert": true, "fields": {"foo": {"$pow": [1, 2]}}}');
-- expect to fail
select  documentdb_api.coll_mod('fam', 'collection', '{"collMod": "collection", "validationLevel": "strict"}');
select documentdb_api.find_and_modify('fam', '{"findAndModify": "collection", "query": {"_id": 3}, "update": {"$set": {"a": "zero"}}, "new": true, "upsert": true, "fields": {"foo": {"$pow": [1, 2]}}}');
select documentdb_api.find_and_modify('fam', '{"findAndModify": "collection", "query": {"_id": 3}, "update": {"$set": {"a": "zero"}}, "new": true, "upsert": true, "bypassDocumentValidation": true, "fields": {"foo": {"$pow": [1, 2]}}}');
SELECT documentdb_api_catalog.bson_dollar_project(document,'{"_id":0,"a":1,"b":1}') FROM documentdb_api.collection('fam', 'collection') ORDER BY document;
set documentdb.enableSchemaValidation = off;
set documentdb.enableBypassDocumentValidation = off;

-- ============================================================================
-- $elemMatch, $slice, and $ positional projection in findAndModify
-- ============================================================================

-- setup: insert documents with arrays for projection operator tests
SELECT 1 FROM documentdb_api.insert_one('fam', 'proj_ops', '{"_id": 1, "arr": [{"x": 1, "y": "a"}, {"x": 2, "y": "b"}, {"x": 3, "y": "c"}], "scalar": 100}');
SELECT 1 FROM documentdb_api.insert_one('fam', 'proj_ops', '{"_id": 2, "arr": [{"x": 10, "y": "p"}, {"x": 20, "y": "q"}], "scalar": 200}');

-- test 1: $elemMatch projection in findAndModify update (return new document)
BEGIN;
  SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "proj_ops", "query": {"_id": 1}, "update": {"$set": {"scalar": 999}}, "fields": {"arr": {"$elemMatch": {"x": 2}}}, "new": true}');
ROLLBACK;

-- test 2: $elemMatch projection in findAndModify update (return old document)
BEGIN;
  SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "proj_ops", "query": {"_id": 1}, "update": {"$set": {"scalar": 999}}, "fields": {"arr": {"$elemMatch": {"x": 2}}}, "new": false}');
ROLLBACK;

-- test 3: $elemMatch projection with no matching element (should return empty array)
BEGIN;
  SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "proj_ops", "query": {"_id": 1}, "update": {"$set": {"scalar": 999}}, "fields": {"arr": {"$elemMatch": {"x": 999}}}, "new": true}');
ROLLBACK;

-- test 4: $elemMatch projection with comparison operators
BEGIN;
  SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "proj_ops", "query": {"_id": 1}, "update": {"$set": {"scalar": 999}}, "fields": {"arr": {"$elemMatch": {"x": {"$gt": 1, "$lt": 3}}}}, "new": true}');
ROLLBACK;

-- test 5: $elemMatch projection combined with inclusion
BEGIN;
  SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "proj_ops", "query": {"_id": 1}, "update": {"$set": {"scalar": 999}}, "fields": {"arr": {"$elemMatch": {"x": 2}}, "scalar": 1}, "new": true}');
ROLLBACK;

-- test 6: $elemMatch projection combined with exclusion of _id
BEGIN;
  SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "proj_ops", "query": {"_id": 1}, "update": {"$set": {"scalar": 999}}, "fields": {"_id": 0, "arr": {"$elemMatch": {"x": 3}}}, "new": true}');
ROLLBACK;

-- test 7: $elemMatch projection in findAndModify remove
BEGIN;
  SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "proj_ops", "query": {"_id": 2}, "remove": true, "fields": {"arr": {"$elemMatch": {"x": 10}}}}');
ROLLBACK;

-- test 8: $elemMatch in both query filter and projection (combined filter and projection)
SELECT 1 FROM documentdb_api.insert_one('fam', 'proj_ops_chat', '{"_id": 1, "name": "Room1", "users": [{"authId": "user-abc", "name": "Tom", "lastRead": null}, {"authId": "user-def", "name": "Jane", "lastRead": null}]}');

BEGIN;
  SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "proj_ops_chat", "query": {"_id": 1, "users": {"$elemMatch": {"authId": "user-abc"}}}, "update": {"$set": {"users.$.lastRead": "msg-100"}}, "fields": {"users": {"$elemMatch": {"authId": "user-abc"}}}, "new": true}');
ROLLBACK;

-- test 9: $slice projection in findAndModify (first 2 elements)
BEGIN;
  SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "proj_ops", "query": {"_id": 1}, "update": {"$set": {"scalar": 999}}, "fields": {"arr": {"$slice": 2}, "_id": 1}, "new": true}');
ROLLBACK;

-- test 10: $slice projection with negative value (last 1 element)
BEGIN;
  SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "proj_ops", "query": {"_id": 1}, "update": {"$set": {"scalar": 999}}, "fields": {"arr": {"$slice": -1}, "_id": 1}, "new": true}');
ROLLBACK;

-- test 11: $ positional projection in findAndModify
BEGIN;
  SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "proj_ops", "query": {"_id": 1, "arr.x": 2}, "update": {"$set": {"scalar": 999}}, "fields": {"arr.$": 1, "_id": 0}, "new": true}');
ROLLBACK;

-- test 12 (negative): $ positional projection without matching array query condition
BEGIN;
  SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "proj_ops", "query": {"_id": 1}, "update": {"$set": {"scalar": 999}}, "fields": {"arr.$": 1}, "new": true}');
ROLLBACK;

-- test 13 (negative): $meta projection in findAndModify (aggregation-only expression)
BEGIN;
  SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "proj_ops", "query": {"_id": 1}, "update": {"$set": {"scalar": 999}}, "fields": {"score": {"$meta": "textScore"}}, "new": true}');
ROLLBACK;

-- test 14: let/variables pass-through with $elemMatch projection
BEGIN;
  SELECT documentdb_api.find_and_modify('fam', '{"findAndModify": "proj_ops", "let": {"ignored": 1}, "query": {"_id": 1}, "update": {"$set": {"scalar": 999}}, "fields": {"arr": {"$elemMatch": {"x": 2}}}, "new": true}');
ROLLBACK;
