client_credentials grant authorization name issue - spring-boot

Question

I am building an app that needs to consume an external api protected with a client_credentials OAuth grant, My configuration is very simple and I was struggling with it for a long time until it worked for a weird rason:
In my original code the configurations is like this:
spring:
security:
oauth2:
client:
registration:
AuthProvider:
authorization-grant-type: client_credentials
client-id: *****
client-secret: *****
scope: resource.READ,resource.WRITE
provider:
AuthProvider:
token-uri: ******
I get the following error:
org.springframework.security.oauth2.client.ClientAuthorizationException: [invalid_client] Client authentication failed (e.g. unknown client, no client authentication included, or unsupported authentication method). The authorization server MAY return an HTTP 401 (Unauthorized) status code to indicate which HTTP authentication schemes are supported.
but when I accidentally made a type in the authorization-grant-type field it worked, I wrote client_credentals instead of the correct client_crentials (without the i)
Question is why it works with a mispelled grant type?

Answer 1

when I accidentally made a type in the authorization-grant-type field
it worked, I wrote client_credentals instead of the correct
client_crentials (without the i)
No, you should carefully check and make sure that the changes you're making are saved properly & part of compilation. The following are valid grant type allowed as part of Ouath2 RFC.
password
authorization_code
client_credentials
implicit
refresh_token
For more details:
https://datatracker.ietf.org/doc/html/rfc6749#section-4.2.1