defmodule Untangle do
@moduledoc """
Logging and debug printing that include location information
"""
@doc "IO.inspect with position information, an optional label and configured not to truncate output too much."
defmacro dump(thing, label \\ "") do
pre = format_label(__CALLER__)
quote do
unquote(__MODULE__).__dbg__("#{unquote(pre)} #{unquote(label)}", unquote(thing))
end
end
@doc "Like `dump`, but for logging at debug level"
defmacro debug(thing, label \\ "") do
pre = format_label(__CALLER__)
quote do
require Logger
{formatted, result} = unquote(__MODULE__).__prepare_dbg__("#{unquote(pre)} #{unquote(label)}", unquote(thing), pretty: true, limit: 10000, printable_limit: 10000)
Logger.debug(formatted)
result
end
end
@doc "Like `dump`, but for logging at info level"
defmacro info(thing, label \\ "") do
pre = format_label(__CALLER__)
thang = Macro.var(:thing, __MODULE__)
quote do
require Logger
{formatted, result} = unquote(__MODULE__).__prepare_dbg__("#{unquote(pre)} #{unquote(label)}", unquote(thing), pretty: true, limit: 10000, printable_limit: 10000)
Logger.info(formatted)
result
end
end
@doc "Like `dump`, but for logging at warn level"
defmacro warn(thing, label \\ "") do
pre = format_label(__CALLER__)
thang = Macro.var(:thing, __MODULE__)
quote do
require Logger
{formatted, result} = unquote(__MODULE__).__prepare_dbg__("#{unquote(pre)} #{unquote(label)}", unquote(thing), pretty: true, limit: 10000, printable_limit: 10000)
Logger.warn(formatted)
result
end
end
@doc """
Similar to `dump`, but for logging at error level, and returns an error tuple:
- an error tuple with the label, if any
- an error tuple with the passed value otherwise
iex> error(:value)
### [error] :value
{:error, :value}
iex> error({:error, :value})
### [error] :value
{:error, :value}
iex> error(:value, "with label")
### [error] with label: :value
{:error, "with label"}
iex> error({:error, :value}, "with label")
### [error] with label: :value
{:error, "with label"}
"""
defmacro error(thing, label \\ "") do
pre = format_label(__CALLER__)
stacktrace = Exception.format_stacktrace(Macro.Env.stacktrace(__CALLER__))
quote do
require Logger
{formatted, result} = unquote(__MODULE__).__prepare_dbg__("#{unquote(pre)} #{unquote(label)}", Untangle.__naked_error__(unquote(thing)), pretty: true, limit: 10000, printable_limit: 10000)
Logger.error(formatted)
Logger.info(unquote(stacktrace))
Untangle.__return_error__(unquote(label), result)
end
end
@doc "Like `debug`, but will do nothing unless the `:debug` option is truthy"
defmacro maybe_dbg(thing, label \\ "", options) do
opts = Macro.var(:opts, __MODULE__)
quote do
unquote(opts) = unquote(options)
if unquote(opts)[:debug] do
debug(unquote(thing), unquote(label))
else
unquote(thing)
end
end
end
@doc "Like `maybe_dbg`, but requires the `:verbose` option to be set. Intended for large outputs."
defmacro maybe_info(thing, label \\ "", options) do
opts = Macro.var(:opts, __MODULE__)
quote do
unquote(opts) = unquote(options)
if unquote(opts)[:verbose] do
info(unquote(thing), unquote(label))
else
unquote(thing)
end
end
end
@doc """
Tries to 'do what i mean'. Requires the `debug` option to be set regardless. If `verbose` is also
set, will inspect else will attempt to print some (hopefully smaller) type-dependent summary of
the data (list length, map keys).
"""
defmacro smart(thing, label \\ "", options) do
pre = format_label(__CALLER__)
opts = Macro.var(:opts, __MODULE__)
thang = Macro.var(:thing, __MODULE__)
quote do
require Logger
unquote(opts) = unquote(options)
unquote(thang) = unquote(thing)
cond do
!unquote(opts)[:debug] -> nil
unquote(opts)[:verbose] ->
Logger.debug("#{unquote(pre)} #{unquote(label)}: #{inspect(unquote(thang), pretty: true, limit: 10000, printable_limit: 10000)}")
is_list(unquote(thang)) ->
Logger.debug("#{unquote(pre)} #{unquote(label)} (length): #{Enum.count(unquote(thang))}")
is_struct(unquote(thang)) ->
Logger.debug("#{unquote(pre)} #{unquote(label)}: %#{unquote(thang).__struct__}{}")
is_map(unquote(thang)) and not is_struct(unquote(thang)) ->
Logger.debug("#{unquote(pre)} #{unquote(label)} (keys): #{inspect(Map.keys(unquote(thang)))}")
true ->
Logger.debug("#{unquote(pre)} #{unquote(label)} (inspect elided, pass `:verbose` to see)")
end
unquote(thang)
end
end
@doc """
Custom backend for `Kernel.dbg/2`.
This function provides a backend for `Kernel.dbg/2`.
This function:
* may log or print information about the given `env`
* may log or print information about `code` and its returned value (using `opts` to inspect terms)
* returns the value returned by evaluating `code`
"""
def custom_dbg(code, options, %Macro.Env{} = env) do
header = "#{format_label(env)} #{options[:label]}:"
quote do
unquote(__MODULE__).__dbg__(unquote(header), unquote(dbg_ast_to_debuggable(code)), unquote(options))
end
end
if not macro_exported?(Kernel, :dbg, 2) do
@doc """
Polyfill for `dbg/2` if running Elixir pre 1.14
"""
defmacro dbg(code \\ quote(do: binding()), options \\ []) do
custom_dbg(code, options, __CALLER__)
end
end
# Pipelines - copied from `Macro.dbg/2`
defp dbg_ast_to_debuggable({:|>, _meta, _args} = pipe_ast) do
value_var = Macro.unique_var(:value, __MODULE__)
values_acc_var = Macro.unique_var(:values, __MODULE__)
[start_ast | rest_asts] = asts = for {ast, 0} <- Macro.unpipe(pipe_ast), do: ast
rest_asts = Enum.map(rest_asts, &Macro.pipe(value_var, &1, 0))
string_asts = Enum.map(asts, &to_string/1)
initial_acc =
quote do
unquote(value_var) = unquote(start_ast)
unquote(values_acc_var) = [unquote(value_var)]
end
values_ast =
for step_ast <- rest_asts, reduce: initial_acc do
ast_acc ->
quote do
unquote(ast_acc)
unquote(value_var) = unquote(step_ast)
unquote(values_acc_var) = [unquote(value_var) | unquote(values_acc_var)]
end
end
quote do
unquote(values_ast)
{:pipe, unquote(string_asts), Enum.reverse(unquote(values_acc_var))}
end
end
defp dbg_ast_to_debuggable({:value, _, _} = value_ast) do
value_ast
end
# Any other AST
defp dbg_ast_to_debuggable(ast) do
quote do: {:value, unquote(to_string(ast)), unquote(ast)}
end
# Made public to be called from Macro.dbg/3, so that we generate as little code
# as possible and call out into a function as soon as we can.
# Copied from `Macro.dbg/2`
@doc false
def __dbg__(header_string, to_debug, options \\ []) do
{formatted, result} = __prepare_dbg__(header_string, to_debug, options)
IO.write(formatted)
result
end
@doc false
def __prepare_dbg__(header_string, to_debug, options \\ []) do
{print_location?, options} = Keyword.pop(options, :print_location, true)
options = Keyword.merge([width: 80, pretty: true, syntax_colors: syntax_colors], options)
{formatted, result} = dbg_format_ast_to_debug(to_debug, options)
formatted =
if print_location? do
[:cyan, :italic, header_string, :reset, "\n", formatted]
else
[formatted]
end
ansi_enabled? = options[:syntax_colors] != []
{IO.ANSI.format(formatted, ansi_enabled?), result}
end
# inspect & format output - copied from `Macro.dbg/2`
defp dbg_format_ast_to_debug({:pipe, code_asts, values}, options) do
result = List.last(values)
[{first_ast, first_value} | asts_with_values] = Enum.zip(code_asts, values)
first_formatted = [dbg_format_ast(first_ast), " ", inspect(first_value, options), ?\n]
rest_formatted =
Enum.map(asts_with_values, fn {code_ast, value} ->
[:faint, "|> ", :reset, dbg_format_ast(code_ast), " ", inspect(value, options), ?\n]
end)
{[first_formatted | rest_formatted], result}
end
defp dbg_format_ast_to_debug({:value, code_ast, value}, options) do
{[dbg_format_ast(code_ast), " ", inspect(value, options), ?\n], value}
end
defp dbg_format_ast_to_debug(value, options) do
{[inspect(value, options), ?\n], value}
end
defp dbg_format_ast(ast) do
[ast, :faint, " #=>", :reset]
end
defp syntax_colors do
if IO.ANSI.enabled?() do
if function_exported?(IO.ANSI, :syntax_colors, 0), do: IO.ANSI.syntax_colors(),
else: [ # polyfill for pre-1.14 elixir
{:atom, :cyan},
{:binary, :default_color},
{:boolean, :magenta},
{:charlist, :yellow},
{:list, :default_color},
{:map, :default_color},
{nil, :magenta},
{:number, :yellow},
{:string, :green},
{:tuple, :default_color}
]
else
[]
end
end
defp format_label(caller) do
app = if function_exported?(Mix.Project, :config, 0), do: Mix.Project.config[:app]
file = Path.relative_to_cwd(caller.file)
case caller.function do
{fun, arity} -> "[#{app}/#{file}:#{caller.line}@#{module_name(caller.module)}.#{fun}/#{arity}]"
_ -> "[#{app}/#{file}:#{caller.line}]"
end
end
defp module_name(name) when is_atom(name), do: module_name(Atom.to_string(name))
defp module_name(name) when is_binary(name), do: String.replace_prefix(name, "Elixir.", "")
@doc false
def __naked_error__({:error, e}), do: e
def __naked_error__(object), do: object
@doc false
def __return_error__(_label, {:error, _} = tuple), do: tuple
def __return_error__(label, object) when is_binary(label) and label !="", do: {:error, label}
def __return_error__(_label, object), do: {:error, object}
end
