Presentation
Clouseau is a silly little inspector. Essentialy is an enhancement over the IO.inspect function. It adds the functionality to display the file, module and line number of the calling location. Also it can optionaly display a line under the inspected term to separate it from other output on the screen.
How to install
Add clouseau
to your list of dependencies in mix.exs
def deps do
[
#...
{:clouseau, "~> 0.3.1"}
]
end
How to use
In order to use Clauseau you first must require the Cl
module
require Cl
Clouseau exports two macros: Cl.inspect/2
and Cl.inspect/3
. Just use them instead of IO.inspect
.
Cl.inspect("test", label: "This is a test")
That’s it. You can return to your code now.
If you wish to do some customization continue reading below.
Switches
Both macros are ready to use out of the box. By default they display the file, module and line where the macro was called, above the label and the inspected term.
clouseau uses OptionParser to parse the switches. The switches can be given directly in the label option. You can use switches to modify what will be shown.
Cl.inspect({"test", 7, %{banana: :yellow}}, label: "--no-file Test showing only module and line")
# Clouseau.ClTest:20
# Test showing only module and line: {"test", 7, %{banana: :yellow}}
Cl.inspect({"test", 7}, label: "-b Test With border", syntax_colors: [number: :blue])
# lib/cltest.ex
# Clouseau.ClTest:26
# Test With border: {"test", 7}
# -------------------------------------------------------------------------------------
# {"test", 7}
Switches that are intended to be used must be grouped in the beginning of the string. Any non-switch group of characters stops the parser and the rest of the line is treated as the text of the label. For example:
Cl.inspect({"test", 7, [banana: "split"]}, label: "--no-module --no-line -b Showing only the --file option. The --no-border option has no effect")
# lib/cltest.ex
# Showing only the --file option. The --no-border option has no effect: {"test", 7, [banana: "split"]}
# --------------------------------------------------------------------------------------------------------------------------------------------------
Note: The first space on the label text is always discarded. The rest of the spaces stay there. This is intentional to keep it as consistent as possible
with IO.inspect
who does not trim white spaces. For example:
Cl.inspect({"test", 7}, label: "-b Test With border", syntax_colors: [number: :blue])
#lib/cltest.ex
#Clouseau.ClTest:26
# Test With border: {"test", 7}
#------------------------------------------------------------------------------------------
The distance between the switch and the text is 6 spaces while the result displays 5 spaces. If, for some reason, you depend on IO.inspect
not triming the
white space, keep this behavior in mind.
The available switches are:
Switch | Type | Default | Shortcut | Description |
---|---|---|---|---|
file: | :boolean | true | f | Display the file where this call happened |
full_path | :boolean | false | none | Display the file as absolute path or relative to project root. Default is relative to project root |
module: | :boolean | true | m | Display the module where this call happened |
line: | :boolean | true | l | Display the line where this call happened |
text: | :boolean | true | t | Display the descriptive text for the label |
border: | :boolean | false | b | Display a border under the inspected term |
If you wish to have your default set of switches you can set options in your config
config :clouseau,
default_switches: [module: true, line: true, file: true, border: true]
Template
clouseau uses an EEx template to display the various parts of the label.
The template uses a custom engine Clouseau.TemplateEngine
instead of the default EEx.SmartEngine
. The differences are:
- It doesn’t add a line break on tag’s end. Instead you shoud add a
"\n"
where you want a line break. The reason for this change is beacuse this way the line break can be controlled with conditionals. - It supports a
has_val?/1
function that returnsfalse
if the value is one ofnil
,false
or""
. - The
@
function desn’t useAccess.fetch/2
butMap.get/2
to get the value. It does not warn or rise any errors. Instead it returns an empty string.
The format of the label is not configurable on the fly. If, for example, it is prefered to display the module before the line, this can be changed only by using a diferent template at compile time.
You can use a custom template by setting in your config. Below is shown the default template as an example.
config :clouseau,
template: """
<% import IO.ANSI %>
<%= if has_val?(file), do: blue() <> @file <> "\n" %>
<%= green() <> @module %><%= if has_val?(module), do: ":" %>
<%= red() <> @line %>
<%= if has_val?(module) || has_val?(line), do: "\n" %>
<%= yellow() <> @text <> reset() %><%= if has_val?(text), do: ": " %>
<%= reset() %>
"""
Credo
clouseau provides two custom credo checks: Clouseau.Check.Warning.ClInspect
and Clouseau.Check.Warning.RequireCl
.
To use them just append them to the :checks
option in your .credo.exs
file.
checks: [
# ... some checks
# Custom checks can be created using `mix credo.gen.check`.
#
{Clouseau.Check.Warning.ClInspect},
{Clouseau.Check.Warning.RequireCl},
]
TODO
- Add some tests
- Add dialyzer documentation