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metasyntactic-variable

Summary: Metasyntactic variable name

Category: Testing

Avoid

package policy

# Using metasyntactic names
foo := ["bar", "baz"]

# ...

Prefer

package policy

# Using names relevant to the context
roles := ["developer", "admin"]

# ...

Rationale​

Using "foo", "bar", "baz" and other metasyntactic variables is occasionally useful in examples, but should be avoided in production policy.

This linter rules forbids any metasyntactic variable names, as listed by Wikipedia:

  • foobar
  • foo
  • bar
  • baz
  • qux
  • quux
  • corge
  • grault
  • garply
  • waldo
  • fred
  • plugh
  • xyzzy
  • thud

Exceptions​

While there are no recommended exceptions to this rule, you could choose to allow metasyntactic variables in tests, or perhaps code meant to be used in examples. When using a proper suffix for tests, like _test.rego, simply configure an ignore pattern with the configuration of this rule:

rules:
  testing:
    metasyntactic-variable:
      level: error
      ignore:
        files:
          - "*_test.rego"

If you'd rather use your own list of forbidden variable names or patterns, see the naming convention rule.

Configuration Options​

This linter rule provides the following configuration options:

rules:
  testing:
    metasyntactic-variable:
      # 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!