use credo

prometheus-erl · Oct 22, 2016 · e3e3d3a · e3e3d3a
1 parent 1f3f1fe
commit e3e3d3a
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Showing 28 changed files with 345 additions and 167 deletions.
diff --git a/.credo.exs b/.credo.exs
@@ -0,0 +1,64 @@
+%{
+  configs: [
+    %{
+      name: "default",
+      check_for_updates: false,
+      files: %{
+        included: ["lib/", "src/", "web/", "apps/", "test/"],
+        excluded: [~r"/_build/", ~r"/deps/"]
+      },
+      checks: [
+        {Credo.Check.Consistency.ExceptionNames},
+        {Credo.Check.Consistency.LineEndings},
+        {Credo.Check.Consistency.SpaceAroundOperators},
+        {Credo.Check.Consistency.SpaceInParentheses},
+        {Credo.Check.Consistency.TabsOrSpaces},
+
+        {Credo.Check.Design.AliasUsage, false},
+
+        {Credo.Check.Design.DuplicatedCode, excluded_macros: [:schema, :setup, :test]},
+
+        {Credo.Check.Design.TagTODO, exit_status: 0},
+        {Credo.Check.Design.TagFIXME, exit_status: 0},
+
+        {Credo.Check.Readability.FunctionNames},
+        {Credo.Check.Readability.LargeNumbers},
+        {Credo.Check.Readability.MaxLineLength, priority: :low, max_length: 90, exit_status: 0},
+        {Credo.Check.Readability.ModuleAttributeNames},
+        {Credo.Check.Readability.ModuleDoc, false},
+        {Credo.Check.Readability.ModuleNames},
+        {Credo.Check.Readability.ParenthesesInCondition},
+        {Credo.Check.Readability.PredicateFunctionNames},
+        {Credo.Check.Readability.TrailingBlankLine},
+        {Credo.Check.Readability.TrailingWhiteSpace},
+        {Credo.Check.Readability.VariableNames},
+
+        {Credo.Check.Refactor.ABCSize},
+        {Credo.Check.Refactor.CondStatements},
+        {Credo.Check.Refactor.FunctionArity},
+        {Credo.Check.Refactor.MatchInCondition},
+        {Credo.Check.Refactor.PipeChainStart},
+        {Credo.Check.Refactor.CyclomaticComplexity},
+        {Credo.Check.Refactor.NegatedConditionsInUnless},
+        {Credo.Check.Refactor.NegatedConditionsWithElse},
+        {Credo.Check.Refactor.Nesting},
+        {Credo.Check.Refactor.UnlessWithElse},
+
+        {Credo.Check.Warning.IExPry},
+        {Credo.Check.Warning.IoInspect},
+        {Credo.Check.Warning.NameRedeclarationByAssignment},
+        {Credo.Check.Warning.NameRedeclarationByCase},
+        {Credo.Check.Warning.NameRedeclarationByDef},
+        {Credo.Check.Warning.NameRedeclarationByFn},
+        {Credo.Check.Warning.OperationOnSameValues},
+        {Credo.Check.Warning.BoolOperationOnSameValues},
+        {Credo.Check.Warning.UnusedEnumOperation},
+        {Credo.Check.Warning.UnusedKeywordOperation},
+        {Credo.Check.Warning.UnusedListOperation},
+        {Credo.Check.Warning.UnusedStringOperation},
+        {Credo.Check.Warning.UnusedTupleOperation},
+        {Credo.Check.Warning.OperationWithConstantResult},
+      ]
+    }
+  ]
+}
diff --git a/.dir-locals.el b/.dir-locals.el
@@ -0,0 +1,4 @@
+((nil         . ((indent-tabs-mode             . nil)
+                 (fill-column                  . 90)
+                 (eval                         . (turn-on-fci-mode))))
+ )
diff --git a/.gitignore b/.gitignore
@@ -15,3 +15,5 @@ erl_crash.dump
 
 # Also ignore archive artifacts (built via "mix archive.build").
 *.ez
+
+.\#*
diff --git a/.travis.yml b/.travis.yml
@@ -9,4 +9,4 @@ sudo: false
 before_script:
   - mix deps.get --only test
 script:
-  - "MIX_ENV=test mix coveralls.travis"
+  - "MIX_ENV=test mix credo --strict && MIX_ENV=test mix coveralls.travis"
diff --git a/lib/prometheus.ex b/lib/prometheus.ex
@@ -1,15 +1,17 @@
 defmodule Prometheus do
-
   @moduledoc"""
 
-  [Prometheus.io](http://prometheus.io) client library powered by [prometheus.erl](https://hexdocs.pm/prometheus)
+  [Prometheus.io](http://prometheus.io) client library powered by
+  [prometheus.erl](https://hexdocs.pm/prometheus)
 
-  Prometheus.ex is a thin, mostly macro-based wrapper around prometheus.erl. While it's pretty straightforward
-  to use prometheus.erl from Elixir, you might prefer prometheus.ex because it gives you:
+  Prometheus.ex is a thin, mostly macro-based wrapper around prometheus.erl.
+  While it's pretty straightforward to use prometheus.erl from Elixir,
+  you might prefer prometheus.ex because it gives you:
 
    - native Elixir syntax;
    - native Elixir exceptions;
-   - configuration helpers that are really handy if you plan to write your custom instrumenter.
+   - configuration helpers that are really handy if you plan to write your custom
+   instrumenter.
 
   ```elixir
   defmodule ExampleInstrumenter do
@@ -23,7 +25,9 @@ defmodule Prometheus do
     end
 
     def instrument(%{time: time, method: method}) do
-      Histogram.observe([name: :http_request_duration_milliseconds, labels: [method]], time)
+      Histogram.observe([name: :http_request_duration_milliseconds,
+                         labels: [method]],
+                        time)
     end
   end
 
@@ -33,7 +37,8 @@ defmodule Prometheus do
    - [Ecto Instrumenter](https://hex.pm/packages/prometheus_ecto);
    - [Elixir plugs Instrumenters and Exporter](https://hex.pm/packages/prometheus_plugs);
    - [Fuse plugin](https://github.com/jlouis/fuse#fuse_stats_prometheus)
-   - [OS process info Collector](https://hex.pm/packages/prometheus_process_collector) (linux-only);
+   - [OS process info Collector](https://hex.pm/packages/prometheus_process_collector)
+   (linux-only);
    - [Phoenix Instrumenter](https://hex.pm/packages/prometheus_phoenix);
    - [RabbitMQ Exporter](https://github.com/deadtrickster/prometheus_rabbitmq_exporter).
 
@@ -49,24 +54,28 @@ defmodule Prometheus do
 
   ### Standard Metrics & Registry
 
-   - `Prometheus.Metric.Counter` - counter metric, to track counts of events or running totals;
+   - `Prometheus.Metric.Counter` - counter metric, to track counts of events or running
+   totals;
    - `Prometheus.Metric.Gauge` - histogram metric, to track distributions of events;
    - `Prometheus.Metric.Histogram` - gauge metric, to report instantaneous values;
    - `Prometheus.Metric.Summary` - summary metric, to track the size of events;
    - `Prometheus.Registry` - working with Prometheus registries.
 
-  All metrics created via `new/1` or `declare/1` macros. The difference is that `new/1` actually wants metric to be
-  new and raises `Prometheus.MFAlreadyExistsError` if it isn't.
+  All metrics created via `new/1` or `declare/1` macros. The difference is that `new/1`
+  actually wants metric to be new and raises `Prometheus.MFAlreadyExistsError`
+  if it isn't.
 
-  Both `new/1` and `declare/1` accept options as [Keyword](http://elixir-lang.org/docs/stable/elixir/Keyword.html).
+  Both `new/1` and `declare/1` accept options as
+  [Keyword](http://elixir-lang.org/docs/stable/elixir/Keyword.html).
   Common options are:
 
    - name - metric name, can be an atom or a string (required);
    - help - metric help, string (required);
    - labels - metric labels, label can be an atom or a string (default is []);
    - registry - Prometheus registry for the metric, can be any term. (default is :default)
 
-  Histogram also accepts `buckets` option. Please refer to respective modules docs for the more information.
+  Histogram also accepts `buckets` option. Please refer to respective modules docs
+  for the more information.
 
   ### General Helpers
 
@@ -75,16 +84,20 @@ defmodule Prometheus do
 
   ### Integration Helpers
 
-   - `Prometheus.Config` - provides standard configuration mechanism for custom instrumenters/exporters.
+   - `Prometheus.Config` - provides standard configuration mechanism
+   for custom instrumenters/exporters.
 
   ### Exposition Formats
 
-   - `Prometheus.Format.Text` - renders metrics for a given registry (default is `:default`) in text format;
-   - `Prometheus.Format.Protobuf` - renders metrics for a given registry (default is `:default`) in protobuf v2 format.
+   - `Prometheus.Format.Text` - renders metrics for a given registry
+   (default is `:default`) in text format;
+   - `Prometheus.Format.Protobuf` - renders metrics for a given registry
+   (default is `:default`) in protobuf v2 format.
 
   ### Advanced
 
-  You will need this modules only if you're writing custom collector for app/lib that can't be instrumented directly.
+  You will need this modules only if you're writing custom collector for app/lib
+  that can't be instrumented directly.
 
    - `Prometheus.Collector` - exports macros for managing/creating collectors;
    - `Prometheus.Model` - provides API for working with underlying Prometheus models.

diff --git a/lib/prometheus/buckets.ex b/lib/prometheus/buckets.ex
@@ -11,8 +11,8 @@ defmodule Prometheus.Buckets do
       iex(2)> Prometheus.Buckets.default()
       [0.005, 0.01, 0.025, 0.05, 0.1, 0.25, 0.5, 1, 2.5, 5, 10]
 
-  Please note these buckets are floats and represent seconds so you'll have to use `Prometheus.Metric.Histogram.dobserve/2` or
-  configure duration_unit as `:seconds`.
+  Please note these buckets are floats and represent seconds so you'll have to use
+  `Prometheus.Metric.Histogram.dobserve/2` or configure duration_unit as `:seconds`.
 
   """
   defmacro default do
@@ -43,7 +43,8 @@ defmodule Prometheus.Buckets do
       iex(2)> Prometheus.Buckets.linear(10, 5, 6)
       [10, 15, 20, 25, 30, 35]
 
-  The function raises `Prometheus.InvalidValueError` exception if `count` is zero or negative.
+  The function raises `Prometheus.InvalidValueError` exception
+  if `count` is zero or negative.
   """
   defmacro linear(start, step, count) do
     Erlang.call([start, step, count])

diff --git a/lib/prometheus/collector.ex b/lib/prometheus/collector.ex
@@ -2,10 +2,12 @@ defmodule Prometheus.Collector do
   @moduledoc """
   A collector for a set of metrics.
 
-  Normal users should use `Prometheus.Metric.Gauge`, `Prometheus.Metric.Counter`, `Prometheus.Metric.Summary`
+  Normal users should use `Prometheus.Metric.Gauge`, `Prometheus.Metric.Counter`,
+  `Prometheus.Metric.Summary`
   and `Prometheus.Metric.Histogram`.
 
-  Implementing `:prometheus_collector` behaviour is for advanced uses such as proxying metrics from another monitoring system.
+  Implementing `:prometheus_collector` behaviour is for advanced uses such as proxying
+  metrics from another monitoring system.
   It is the responsibility of the implementer to ensure produced metrics are valid.
 
   You will be working with Prometheus data model directly (see `Prometheus.Model` ).
@@ -24,9 +26,9 @@ defmodule Prometheus.Collector do
   ```
   iex(3)> defmodule Prometheus.VMMemoryCollector do
   ...(3)>   use Prometheus.Collector
-  ...(3)>   
+  ...(3)>
   ...(3)>   @labels [:processes, :atom, :binary, :code, :ets]
-  ...(3)>   
+  ...(3)>
   ...(3)>   def collect_mf(_registry, callback) do
   ...(3)>     memory = :erlang.memory()
   ...(3)>     callback.(create_gauge(
@@ -35,22 +37,22 @@ defmodule Prometheus.Collector do
   ...(3)>           memory))
   ...(3)>     :ok
   ...(3)>   end
-  ...(3)>   
+  ...(3)>
   ...(3)>   def collect_metrics(:erlang_vm_bytes_total, memory) do
   ...(3)>     Prometheus.Model.gauge_metrics(
   ...(3)>       for label <- @labels do
   ...(3)>         {[type: label], memory[label]}
   ...(3)>       end)
   ...(3)>   end
-  ...(3)>   
+  ...(3)>
   ...(3)>   defp create_gauge(name, help, data) do
   ...(3)>     Prometheus.Model.create_mf(name, help, :gauge, __MODULE__, data)
   ...(3)>   end
   ...(3)> end
   iex(4)> Prometheus.Registry.register_collector(Prometheus.VMMemoryCollector)
   :ok
   iex(5)> r = ~r/# TYPE erlang_vm_bytes_total gauge
-  ...(5)> # HELP erlang_vm_bytes_total 
+  ...(5)> # HELP erlang_vm_bytes_total
   ...(5)> The total amount of memory currently allocated.
   ...(5)> erlang_vm_bytes_total{type=\"processes\"} [1-9]
   ...(5)> erlang_vm_bytes_total{type=\"atom\"} [1-9]

diff --git a/lib/prometheus/config.ex b/lib/prometheus/config.ex
@@ -14,7 +14,8 @@ defmodule Prometheus.Config do
       :default
       iex(6)> MyInstrumenter.Config.required_option!(MyInstrumenter)
       ** (Prometheus.Config.KeyNotFoundError) mandatory option :required_option not found in PrometheusTest.MyInstrumenter instrumenter/collector config
-      iex(7)> Application.put_env(:prometheus, MyInstrumenter, [required_option: "Hello world!"])
+      iex(7)> Application.put_env(:prometheus, MyInstrumenter,
+      ...(7)>                     [required_option: "Hello world!"])
       :ok
       iex(8)> MyInstrumenter.Config.required_option!(MyInstrumenter)
       "Hello world!"
@@ -29,7 +30,8 @@ defmodule Prometheus.Config do
 
     def message(%{option: option, key: key}) do
       friendly_key_name = String.replace_leading("#{key}", "Elixir.", "")
-      "mandatory option :#{option} not found in #{friendly_key_name} instrumenter/collector config"
+      "mandatory option :#{option} not found" <>
+        " in #{friendly_key_name} instrumenter/collector config"
     end
   end
 
@@ -51,13 +53,15 @@ defmodule Prometheus.Config do
         end
 
         defp config(key, option, default) do
-          config(key)
+          key
+          |> config()
           |> Keyword.get(option, default)
         end
 
         defp config(key, option) do
           try do
-            config(key)
+            key
+            |> config()
             |> Keyword.fetch!(option)
           rescue
             e in KeyError -> raise %KeyNotFoundError{key: key, option: option}

diff --git a/lib/prometheus/contrib/http.ex b/lib/prometheus/contrib/http.ex
@@ -27,7 +27,7 @@ defmodule Prometheus.Contrib.HTTP do
     quote do
       require Prometheus.Error
       Prometheus.Error.with_prometheus_error(
-	:prometheus_http.status_class(unquote(code))
+        :prometheus_http.status_class(unquote(code))
       )
     end
   end

diff --git a/lib/prometheus/erlang.ex b/lib/prometheus/erlang.ex
@@ -54,8 +54,8 @@ defmodule Prometheus.Erlang do
           require Prometheus.Error
 
           Prometheus.Error.with_prometheus_error(
-            unquote(module).unquote(function)(unquote(registry), unquote(name), unquote(labels),
-              unquote_splicing(arguments)))
+            unquote(module).unquote(function)(unquote(registry), unquote(name),
+              unquote(labels), unquote_splicing(arguments)))
 
         end
       _ ->
@@ -75,14 +75,19 @@ defmodule Prometheus.Erlang do
 
   defp parse_metric_call_args(mf_or_spec, spec, arguments) do
     case mf_or_spec do
-      {_,_} -> {mf_or_spec, spec, arguments} ## Erlang.metric_call({:prometheus_counter, :dinc}, spec, [value])
-      _ when is_atom(mf_or_spec) -> {mf_or_spec, spec, arguments} ## Erlang.metric_call(:inc, spec, [value])
+      ## Erlang.metric_call({:prometheus_counter, :dinc}, spec, [value])
+      {_,_} -> {mf_or_spec, spec, arguments}
+      ## Erlang.metric_call(:inc, spec, [value])
+      _ when is_atom(mf_or_spec) -> {mf_or_spec, spec, arguments}
       _ ->
-        [] = arguments ## args are 'shifted' to left
+        ## args are 'shifted' to left
+        [] = arguments
         if spec == false do
-          {false, mf_or_spec, []} ## only spec is needed, e.g. Erlang.metric_call(spec)
+          ## only spec is needed, e.g. Erlang.metric_call(spec)
+          {false, mf_or_spec, []}
         else
-          {false, mf_or_spec, spec} ## Erlang.metric_call(spec, [value])
+          ## Erlang.metric_call(spec, [value])
+          {false, mf_or_spec, spec}
         end
     end
   end

diff --git a/lib/prometheus/error.ex b/lib/prometheus/error.ex
@@ -1,6 +1,7 @@
 defmodule Prometheus.InvalidValueError do
   @moduledoc """
-  Raised when given `value` is invalid i.e. when you pass a negative number to `Prometheus.Metric.Counter.inc/2`.
+  Raised when given `value` is invalid i.e. when you pass a negative number to
+  `Prometheus.Metric.Counter.inc/2`.
   """
   defexception [:value, :orig_message]
 
@@ -11,8 +12,8 @@ end
 
 defmodule Prometheus.InvalidMetricNameError do
   @moduledoc """
-  Raised when given metric `name` is invalid i.e. can't be represented as printable utf-8 string that matches
-  `^[a-zA-Z_:][a-zA-Z0-9_:]*$` regular expression.
+  Raised when given metric `name` is invalid i.e. can't be represented as printable utf-8
+  string that matches `^[a-zA-Z_:][a-zA-Z0-9_:]*$` regular expression.
   """
   defexception [:name]
 
@@ -66,8 +67,8 @@ end
 
 defmodule Prometheus.InvalidLabelNameError do
   @moduledoc """
-  Raised when label `name` is invalid i.e. can't be represented as printable utf-8 string that matches
-  `^[a-zA-Z_][a-zA-Z0-9_]*$` regular expression or starts with `__`.
+  Raised when label `name` is invalid i.e. can't be represented as printable utf-8 string
+  that matches `^[a-zA-Z_][a-zA-Z0-9_]*$` regular expression or starts with `__`.
 
   Metric can impose further restrictions on label names.
   """
@@ -142,6 +143,8 @@ end
 defmodule Prometheus.Error do
   @moduledoc false
 
+  @lint [{Credo.Check.Refactor.ABCSize, false},
+         {Credo.Check.Refactor.CyclomaticComplexity, false}]
   def normalize(erlang_error) do
     case erlang_error do
       %ErlangError{original: original} ->
@@ -165,7 +168,8 @@ defmodule Prometheus.Error do
           {:histogram_no_buckets, buckets} ->
             %Prometheus.HistogramNoBucketsError{buckets: buckets}
           {:histogram_invalid_buckets, buckets, message} ->
-            %Prometheus.HistogramInvalidBucketsError{buckets: buckets, orig_message: message}
+            %Prometheus.HistogramInvalidBucketsError{buckets: buckets,
+                                                     orig_message: message}
           {:histogram_invalid_bound, bound} ->
             %Prometheus.HistogramInvalidBoundError{bound: bound}
           {:missing_metric_spec_key, key, spec} ->
Original file line number	Diff line number	Diff line change
Expand Up		@@ -15,3 +15,5 @@ erl_crash.dump

		# Also ignore archive artifacts (built via "mix archive.build").
		*.ez

		.\#*