commit 85de10d412fb719c29901a7010f363276f95c4df
author Edwin Kempin <ekempin@google.com> Thu Jul 01 14:41:15 2021 +0200
committer Edwin Kempin <ekempin@google.com> Thu Jul 01 15:00:05 2021 +0200
tree e96ca39f48a51b5fe1684f76b6ee2b02e342edb4
parent b503d729b323553d1cd924e0efd92d0f96dda514

Fix error handling for per-file imports that use import mode ALL

Code owner config files can import other code owner config files. Which
rules are being imported depends on the import mode:

* ALL: all rules are imported
* GLOBAL_CODE_OWNER_SETS_ONLY: only rules for global code owners are
  imported (aka folder code owners)

For per-file code owner sets only imports with mode
GLOBAL_CODE_OWNER_SETS_ONLY are allowed.

If the find-owners backend is used, the import keyword controls which
import mode is being used:

* include = ALL
* file: = GLOBAL_CODE_OWNER_SETS_ONLY

OWNERS files with a per-file rule that use the include keyword, although
the include keyword is not allowed for per-file rules, are rejected as
non-parseable. However instead of throwing a
CodeOwnerConfigParseException, FindOwnersConfigParser throwed an
IllegalStateException. This was bad because IllegalStateExceptions are
causing internal server errors, whereas CodeOwnerConfigParseExceptions
are handled as configuration errors. Configuration errors make requests
fail with 409 Conflict and a proper error message, or if they occur
during the submit rule evaluation they cause the status to be set to
RULE_ERROR. This way the user can find out what's wrong and fix the bad
OWNERS file.

While we are at this, improve the error message. Talking about import
mode ALL doesn't make sense from a user's perspective. Rather tell them
directly that the include keyword is not supported for per-file rules.

Signed-off-by: Edwin Kempin <ekempin@google.com>
Change-Id: I382aae540dcc69fcda30a565c75aa696a866664c