Java MongoDB collection.insert为spock单元测试返回null

Question

I am writing a unit test case to verify my method insertToCollection is working fine or not.

InsertToMongoCollection.java

protected void insertToCollection() {
   collection.insert(recordList);
}

SPOCK:

def "InsertToMongoCollection"() {
   given:
   Record record = new Record()
   record.setId("111")
   Collection collection= Mock()
   InsertToMongoCollection.collection = collection

   when:
   InsertToMongoCollection.addToGroup(record) // this inserts into recordList
   List<Record> result = collection.insertToCollection()

   then:
   result.count() == 1
}

The mocking is done correctly and the recordList also has 1 record. If I debug and see. But when the collection.insert is called, the result is null.

Answer 1

insertToCollection had a void return type, so will return null when you do

List<Record> result = collection.insertToCollection()

Change the return type of the method so you can test it, or run up a fake mongo, and check the records are inserted