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avoid-get-and-list-prefix

Summary: Avoid get_ and list_ prefix for rules and functions

Category: Style

Avoid

package policy

get_first_name(user) := split(user.name, " ")[0]

# Partial rule, so a set of users is to be expected
list_developers contains user if {
    some user in data.application.users
    user.type == "developer"
}

Prefer

package policy

# "get" is implied
first_name(user) := split(user.name, " ")[0]

# Partial rule, so a set of users is to be expected
developers contains user if {
    some user in data.application.users
    user.type == "developer"
}

Rationale​

Since Rego evaluation is generally free of side effects, any rule or function is essentially a "getter". Adding a get_ prefix to a rule or function (like get_resources) thus adds little of value compared to just naming it resources. Additionally, the type and return value of the rule should serve to tell whether a rule might return a single value (i.e. a complete rule) or a collection (a partial rule).

Exceptions​

Using is_, or has_ for boolean helper functions, like is_admin(user) may be easier to comprehend than admin(user).

Configuration Options​

This linter rule provides the following configuration options:

rules:
  style:
    avoid-get-and-list-prefix:
      # one of "error", "warning", "ignore"
      level: error

Community​

If you think you've found a problem with this rule or its documentation, would like to suggest improvements, new rules, or just talk about Regal in general, please join us in the #regal channel in the Styra Community Slack!