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W0086 - No ?config/2 macro

This diagnostic is disabled by default. Enable it via [linters.no_ct_config_macro] enabled = true in the project's .elp_lint.toml.

Example​

    -module(main_SUITE).

    my_testcase(Config) ->
        PrivDir = ?config(priv_dir, Config).
%%                ^^^^^^^^^^^^^^^^^^^^^^^^^ 💡 warning: W0086: The `?config/2` macro is deprecated; use `proplists:get_value/2` instead.

Explanation​

The Common Test ?config(Key, Config) macro (from ct.hrl) is defined as test_server:lookup_config/2, which prints Could not find element ~tp in Config. to stdout when the key is missing. proplists:get_value(Key, Config) returns undefined silently, so it is preferred.

The two differ on entries that are not {Key, Value} pairs: proplists treats a bare atom Key as {Key, true}, whereas test_server:lookup_config/2 only ever looks at 2-tuples. A Common Test config is built from 2-tuples, so the rewrite is equivalent there — which is why the diagnostic only fires in Common Test suites and test helpers.

Fix​

Rewrite the call as proplists:get_value(Key, Config):

    my_testcase(Config) ->
        PrivDir = proplists:get_value(priv_dir, Config).