whereFieldPath method
Creates and returns a new Query with the additional filter that documents must contain the specified field and that its value should satisfy the relation constraint provided.
This function returns a new (immutable) instance of the Query (rather than modify the existing instance) to impose the filter.
@param fieldPath The path to compare @param opStr The operation string (e.g "<", "<=", "==", ">", ">="). @param value The value for comparison @return The created Query.
Implementation
@JS('where')
external Query whereFieldPath(JSAny fieldPath, String opStr, JSAny value);