Details
Minor Description
When calculating the schema compatibility can read (schema A can read or not an event written using a schema B) we expect a true or false result, but in some cases the code panics with a message (reason of schema not being compatible) which I think it should not.
Example:
let schema_1 = Schema::parse_str(
r#"{
"type": "record",
"name": "StatisticsMap",
"fields": [
{"name": "success", "type": {"type": "map", "values": "int"}}
]
}"#)?;
let schema_2 = Schema::parse_str(
r#"{
"type": "record",
"name": "StatisticsMap",
"fields": [
{"name": "success", "type": ["null", {"type": "map", "values": "int"}], "default": null}
]
}"#)?
assert!(SchemaCompatibility::can_read(&schema_1, &schema_2)); # true as expected
assert!(SchemaCompatibility::can_read(&schema_2, &schema_1)); # expected result false!!
The application panicked (crashed).
Message: internal error: entered unreachable code: writers_schema should have been Schema::Map
PS: If the intention is to give feedback to end users when schemas are not compatible then it makes sense the panic (maybe a Result should be better?) but the feedback should be present every time that the result is false, which is not the case.
I have a PR ready to fix this in case that we want to change the current behaviour
