source_test.go:40: Expected JSON data for class 9A to be [{"class":"9A","name":"Ivan"},{"class":"9A","name":"John"}], but got {"class":"9A","name":"Ivan"}{"class":"9A","name":"John"} source_test.go:40: Expected JSON data for class 9B to be [{"class":"9B","name":"Oleg"},{"class":"9B","name":"Maria"}], but got {"class":"9B","name":"Oleg"}{"class":"9B","name":"Maria"} FAIL

The test failed because the expected JSON data for class 9A and class 9B were not in the correct format. The expected JSON data should be in an array format with each object separated by a comma.

For class 9A, the expected JSON data should be: [{ "class": "9A", "name": "Ivan" },{ "class": "9A", "name": "John" }]

For class 9B, the expected JSON data should be: [{ "class": "9B", "name": "Oleg" },{ "class": "9B", "name": "Maria" }]

But instead, the actual JSON data provided did not have the objects separated by a comma, causing the test to fail.