fingerprintKey function
Stable key joining a diagnostic's identity. Both the rule side (write) and the reporter side (read) reconstruct the same key from the rule id, absolute file path and 1-based line/column.
Implementation
String fingerprintKey({
required String ruleId,
required String filePath,
required int line,
required int column,
}) =>
'$ruleId|$filePath|$line|$column';