How well do you know the possibilities offered by the built-in Elixir mechanisms? You may be surprised, but the behavior of the popular inspect can be easily modified.
I would like to present some important options. They will adjust the display to our needs. Maybe it will make your daily work more accessible and make it a bit more comfortable.
List of integers as a list, not as a character
How often have you worked with lists that contain a single integer? How often did you expect to see a character in a field that should be on a list?
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iex(1)> [78]
'N'
iex(2)> [95]
'_'
iex(3)> [120]
'x'
When testing, it can be a problem, and you need to modify the data.
However, the problem should be fixed thanks to charlists: :as_lists.
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iex(1)> IEx.configure(inspect: [charlists: :as_lists])
:ok
iex(2)> [78]
[78]
iex(3)> [95]
[95]
iex(4)> [120]
[120]
iex(5)> inspect([120], charlists: :as_lists)
"[120]"
No more truncating content
In order not to overwhelm with information, a limit is used. It allows you to limit the amount of information displayed in the terminal. It applies to the inspected items: for tuples, bitstrings, maps, lists, and any other collection of items.
The default is 50, which may not be enough in some cases.
You can change this (to any positive integer) or use :infinity to not worry about the limit at all.
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iex(1)> 1..60 |> Enum.to_list
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22,
23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42,
43, 44, 45, 46, 47, 48, 49, 50, ...]
iex(2)> IEx.configure(inspect: [limit: :infinity])
:ok
iex(3)> 1..60 |> Enum.to_list
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22,
23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42,
43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60]
Your own formatting style
With the newest (released a few days ago) version of Elixir 1.13, it is possible to control the way information is displayed. You can prepare your own implementation of default_inspect_fun/1, which will change the default data formatting.
It can be an excellent way to hide sensitive information in your logs. It will be one of the options to eliminate, for example, a hashed password.
It is worth highlighting the information provided directly in the description of the function. Libraries are advised not to set their own settings for this feature as other applications must control these. Instead, they should define their own modules with custom auditing implementations and ask the user to use them.
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previous_fun = Inspect.Opts.default_inspect_fun()
Inspect.Opts.default_inspect_fun(fn
%{hashed_password: _} = map, opts ->
previous_fun.(%{map | hashed_password: "[SECRET]"}, opts)
value, opts ->
previous_fun.(value, opts)
end)