OeditusCredo.Check.Warning.UnsafeMapAccess (OeditusCredo v0.5.0)

Basics

This check has a base priority of normal and works with any version of Elixir.

Explanation

Using bracket access (map[:key]) on a map with atom keys silently returns nil when the key is missing. The nil then propagates and surfaces as a confusing error far from the source.

Prefer dot access, which raises a KeyError on missing keys and allows Elixir 1.20's type system to propagate key requirements across call sites.

Bad:

config = %{timeout: 5000}
config[:timeout]

Good:

config = %{timeout: 5000}
config.timeout

This check requires the typle package and Elixir >= 1.20. When either is unavailable, the check is silently skipped.

Check-Specific Parameters

Use the following parameters to configure this check:

:exclude_test_files

Set to true to skip test files (default: false)

This parameter defaults to nil.

General Parameters

Like with all checks, general params can be applied.

Parameters can be configured via the .credo.exs config file.