From d9e204074898b347a12f63932916c1318dc4f7a5 Mon Sep 17 00:00:00 2001
From: Zach Daniel <zachary.s.daniel@gmail.com>
Date: Mon, 27 Aug 2018 12:00:17 -0400
Subject: [PATCH] standardize return types from strategies (and by proxy from
 Spandex) (#62)

* standardize return types from strategies (and by proxy from Spandex)
---
 README.md                      |  12 ++--
 lib/spandex.ex                 | 118 +++++++++++++++++++++------------
 lib/strategy.ex                |   5 +-
 lib/strategy/pdict.ex          |  25 ++++---
 lib/tracer.ex                  |  20 +++---
 test/plug/add_context_test.exs |   4 +-
 test/plug/end_trace_test.exs   |   2 +-
 test/spandex_test.exs          |  40 +++++++++--
 8 files changed, 147 insertions(+), 79 deletions(-)

diff --git a/README.md b/README.md
index 7b3e6f5..3504f71 100644
--- a/README.md
+++ b/README.md
@@ -103,24 +103,24 @@ defmodule ManuallyTraced do
 
   # Does not handle exceptions for you.
   def trace_me() do
-    _ = Tracer.start_trace("my_trace") #also opens a span
-    _ = Tracer.update_span(service: :my_app, type: :db)
+    Tracer.start_trace("my_trace") #also opens a span
+    Tracer.update_span(service: :my_app, type: :db)
 
     result = span_me()
 
-    _ = Tracer.finish_trace()
+    Tracer.finish_trace()
 
     result
   end
 
   # Does not handle exceptions for you.
   def span_me() do
-    _ = Tracer.start_span("this_span")
-    _ = Tracer.update_span(service: :my_app, type: :web)
+    Tracer.start_span("this_span")
+    Tracer.update_span(service: :my_app, type: :web)
 
     result = span_me_also()
 
-    _ = Tracer.finish_span()
+    Tracer.finish_span()
   end
 
   # Handles exception at the span level. Trace still must be reported.
diff --git a/lib/spandex.ex b/lib/spandex.ex
index 3d3cfda..36cc77b 100644
--- a/lib/spandex.ex
+++ b/lib/spandex.ex
@@ -26,7 +26,7 @@ defmodule Spandex do
   def start_trace(name, opts) do
     strategy = opts[:strategy]
 
-    if strategy.get_trace(opts[:tracer]) do
+    if strategy.trace_active?(opts[:trace_key]) do
       Logger.error("Tried to start a trace over top of another trace.")
       {:error, :trace_running}
     else
@@ -44,12 +44,15 @@ defmodule Spandex do
   def start_span(name, opts) do
     strategy = opts[:strategy]
 
-    case strategy.get_trace(opts[:tracer]) do
-      nil ->
+    case strategy.get_trace(opts[:trace_key]) do
+      {:error, :no_trace_context} = error ->
         Logger.error("Tried to start a span without an active trace.")
-        {:error, :no_trace_context}
+        error
 
-      trace ->
+      {:error, _} = error ->
+        error
+
+      {:ok, trace} ->
         do_start_span(name, trace, opts)
     end
   end
@@ -66,17 +69,20 @@ defmodule Spandex do
   def update_span(opts, top?) do
     strategy = opts[:strategy]
 
-    case strategy.get_trace(opts[:tracer]) do
-      nil ->
+    case strategy.get_trace(opts[:trace_key]) do
+      {:error, :no_trace_context} = error ->
         Logger.error("Tried to update a span without an active trace.")
-        {:error, :no_trace_context}
+        error
 
-      %Trace{stack: []} ->
+      {:ok, %Trace{stack: []}} ->
         Logger.error("Tried to update a span without an active span.")
         {:error, :no_span_context}
 
-      trace ->
+      {:ok, trace} ->
         do_update_span(trace, opts, top?)
+
+      {:error, _} = error ->
+        error
     end
   end
 
@@ -99,15 +105,18 @@ defmodule Spandex do
   def update_all_spans(opts) do
     strategy = opts[:strategy]
 
-    case strategy.get_trace(opts[:tracer]) do
-      nil ->
+    case strategy.get_trace(opts[:trace_key]) do
+      {:error, :no_trace_context} = error ->
         Logger.error("Tried to update a span without an active trace.")
-        {:error, :no_trace_context}
+        error
 
-      %Trace{stack: stack, spans: spans} = trace ->
+      {:ok, %Trace{stack: stack, spans: spans} = trace} ->
         new_stack = Enum.map(stack, &update_or_keep(&1, opts))
         new_spans = Enum.map(spans, &update_or_keep(&1, opts))
-        strategy.put_trace(opts[:tracer], %{trace | stack: new_stack, spans: new_spans})
+        strategy.put_trace(opts[:trace_key], %{trace | stack: new_stack, spans: new_spans})
+
+      {:error, _} = error ->
+        error
     end
   end
 
@@ -122,16 +131,19 @@ defmodule Spandex do
     strategy = opts[:strategy]
     adapter = opts[:adapter]
 
-    case strategy.get_trace(opts[:tracer]) do
-      nil ->
+    case strategy.get_trace(opts[:trace_key]) do
+      {:error, :no_trace_context} = error ->
         Logger.error("Tried to finish a trace without an active trace.")
-        {:error, :no_trace_context}
+        error
 
-      %Trace{spans: spans, stack: stack} ->
+      {:ok, %Trace{spans: spans, stack: stack}} ->
         unfinished_spans = Enum.map(stack, &ensure_completion_time_set(&1, adapter))
         sender = opts[:sender] || adapter.default_sender()
         sender.send_spans(spans ++ unfinished_spans)
-        strategy.delete_trace(opts[:tracer])
+        strategy.delete_trace(opts[:trace_key])
+
+      {:error, _} = error ->
+        error
     end
   end
 
@@ -147,19 +159,28 @@ defmodule Spandex do
     strategy = opts[:strategy]
     adapter = opts[:adapter]
 
-    case strategy.get_trace(opts[:tracer]) do
-      nil ->
+    case strategy.get_trace(opts[:trace_key]) do
+      {:error, :no_trace_context} = error ->
         Logger.error("Tried to finish a span without an active trace.")
-        {:error, :no_trace_context}
+        error
 
-      %Trace{stack: []} ->
+      {:ok, %Trace{stack: []}} ->
         Logger.error("Tried to finish a span without an active span.")
         {:error, :no_span_context}
 
-      %Trace{stack: [span | tail], spans: spans} = trace ->
+      {:ok, %Trace{stack: [span | tail], spans: spans} = trace} ->
         finished_span = ensure_completion_time_set(span, adapter)
-        strategy.put_trace(opts[:tracer], %{trace | stack: tail, spans: [finished_span | spans]})
+
+        strategy.put_trace(opts[:trace_key], %{
+          trace
+          | stack: tail,
+            spans: [finished_span | spans]
+        })
+
         {:ok, finished_span}
+
+      {:error, _} = error ->
+        error
     end
   end
 
@@ -182,12 +203,14 @@ defmodule Spandex do
   def current_trace_id(opts) do
     strategy = opts[:strategy]
 
-    case strategy.get_trace(opts[:tracer]) do
-      nil ->
-        nil
-
-      %Trace{id: id} ->
+    case strategy.get_trace(opts[:trace_key]) do
+      {:ok, %Trace{id: id}} ->
         id
+
+      {:error, _} ->
+        # TODO: Alter the return type of this interface to allow for returning
+        # errors from fetching the trace.
+        nil
     end
   end
 
@@ -207,10 +230,17 @@ defmodule Spandex do
   def current_span(opts) do
     strategy = opts[:strategy]
 
-    case strategy.get_trace(opts[:tracer]) do
-      nil -> nil
-      %Trace{stack: []} -> nil
-      %Trace{stack: [span | _]} -> span
+    case strategy.get_trace(opts[:trace_key]) do
+      {:ok, %Trace{stack: []}} ->
+        nil
+
+      {:ok, %Trace{stack: [span | _]}} ->
+        span
+
+      {:error, _} ->
+        # TODO: Alter the return type of this interface to allow for returning
+        # errors from fetching the trace.
+        nil
     end
   end
 
@@ -225,7 +255,7 @@ defmodule Spandex do
     strategy = opts[:strategy]
     opts = Keyword.put(opts, :parent_id, span_id)
 
-    if strategy.get_trace(opts[:tracer]) do
+    if strategy.trace_active?(opts[:trace_key]) do
       Logger.error("Tried to continue a trace over top of another trace.")
       {:error, :trace_already_present}
     else
@@ -243,7 +273,7 @@ defmodule Spandex do
   def continue_trace_from_span(name, span, opts) do
     strategy = opts[:strategy]
 
-    if strategy.get_trace(opts[:tracer]) do
+    if strategy.trace_active?(opts[:trace_key]) do
       Logger.error("Tried to continue a trace over top of another trace.")
       {:error, :trace_already_present}
     else
@@ -270,7 +300,7 @@ defmodule Spandex do
 
     with {:ok, top_span} <- span(name, opts, trace_id, adapter) do
       trace = %Trace{id: trace_id, stack: [top_span], spans: []}
-      strategy.put_trace(opts[:tracer], trace)
+      strategy.put_trace(opts[:trace_key], trace)
     end
   end
 
@@ -280,7 +310,7 @@ defmodule Spandex do
 
     with {:ok, span} <- Span.child_of(span, name, adapter.span_id(), adapter.now(), opts) do
       trace = %Trace{id: adapter.trace_id(), stack: [span], spans: []}
-      strategy.put_trace(opts[:tracer], trace)
+      strategy.put_trace(opts[:trace_key], trace)
     end
   end
 
@@ -289,7 +319,7 @@ defmodule Spandex do
     adapter = opts[:adapter]
 
     with {:ok, span} <- Span.child_of(current_span, name, adapter.span_id(), adapter.now(), opts),
-         {:ok, _trace} <- strategy.put_trace(opts[:tracer], %{trace | stack: [span | trace.stack]}) do
+         {:ok, _trace} <- strategy.put_trace(opts[:trace_key], %{trace | stack: [span | trace.stack]}) do
       Logger.metadata(span_id: span.id)
       {:ok, span}
     end
@@ -300,7 +330,7 @@ defmodule Spandex do
     adapter = opts[:adapter]
 
     with {:ok, span} <- span(name, opts, trace_id, adapter),
-         {:ok, _trace} <- strategy.put_trace(opts[:tracer], %{trace | stack: [span]}) do
+         {:ok, _trace} <- strategy.put_trace(opts[:trace_key], %{trace | stack: [span]}) do
       Logger.metadata(span_id: span.id)
       {:ok, span}
     end
@@ -314,7 +344,7 @@ defmodule Spandex do
     with {:ok, span} <- span(name, opts, trace_id, adapter) do
       Logger.metadata(trace_id: trace_id, span_id: span.id)
       trace = %Trace{spans: [], stack: [span], id: trace_id}
-      strategy.put_trace(opts[:tracer], trace)
+      strategy.put_trace(opts[:trace_key], trace)
     end
   end
 
@@ -322,7 +352,7 @@ defmodule Spandex do
     strategy = opts[:strategy]
     new_stack = List.update_at(stack, -1, &update_or_keep(&1, opts))
 
-    with {:ok, _trace} <- strategy.put_trace(opts[:tracer], %{trace | stack: new_stack}) do
+    with {:ok, _trace} <- strategy.put_trace(opts[:trace_key], %{trace | stack: new_stack}) do
       {:ok, Enum.at(new_stack, -1)}
     end
   end
@@ -332,7 +362,7 @@ defmodule Spandex do
     updated_span = update_or_keep(current_span, opts)
     new_stack = [updated_span | other_spans]
 
-    with {:ok, _trace} <- strategy.put_trace(opts[:tracer], %{trace | stack: new_stack}) do
+    with {:ok, _trace} <- strategy.put_trace(opts[:trace_key], %{trace | stack: new_stack}) do
       {:ok, updated_span}
     end
   end
diff --git a/lib/strategy.ex b/lib/strategy.ex
index aa68957..fe80507 100644
--- a/lib/strategy.ex
+++ b/lib/strategy.ex
@@ -6,7 +6,8 @@ defmodule Spandex.Strategy do
 
   alias Spandex.Trace
 
-  @callback get_trace(tracer) :: Trace.t() | nil
+  @callback delete_trace(tracer) :: {:ok, Trace.t()} | {:error, term}
+  @callback get_trace(tracer) :: {:ok, Trace.t()} | {:error, term}
   @callback put_trace(tracer, Trace.t()) :: {:ok, Trace.t()} | {:error, term}
-  @callback delete_trace(tracer) :: :ok | {:error, term}
+  @callback trace_active?(tracer) :: boolean
 end
diff --git a/lib/strategy/pdict.ex b/lib/strategy/pdict.ex
index 49a7938..cba0248 100644
--- a/lib/strategy/pdict.ex
+++ b/lib/strategy/pdict.ex
@@ -7,21 +7,30 @@ defmodule Spandex.Strategy.Pdict do
   @behaviour Spandex.Strategy
 
   @impl Spandex.Strategy
-  def get_trace(tracer) do
-    Process.get({:spandex_trace, tracer})
+  def trace_active?(trace_key) do
+    Process.get({:spandex_trace, trace_key})
   end
 
   @impl Spandex.Strategy
-  def put_trace(tracer, trace) do
-    Process.put({:spandex_trace, tracer}, trace)
+  def get_trace(trace_key) do
+    trace = Process.get({:spandex_trace, trace_key})
 
-    {:ok, trace}
+    if trace do
+      {:ok, trace}
+    else
+      {:error, :no_trace_context}
+    end
   end
 
   @impl Spandex.Strategy
-  def delete_trace(tracer) do
-    Process.delete({:spandex_trace, tracer})
+  def put_trace(trace_key, trace) do
+    Process.put({:spandex_trace, trace_key}, trace)
 
-    :ok
+    {:ok, trace}
+  end
+
+  @impl Spandex.Strategy
+  def delete_trace(trace_key) do
+    {:ok, Process.delete({:spandex_trace, trace_key})}
   end
 end
diff --git a/lib/tracer.ex b/lib/tracer.ex
index f916ed4..2456703 100644
--- a/lib/tracer.ex
+++ b/lib/tracer.ex
@@ -44,7 +44,7 @@ defmodule Spandex.Tracer do
                    services: {:keyword, :atom},
                    strategy: :atom,
                    sender: :atom,
-                   tracer: :atom
+                   trace_key: :atom
                  ],
                  required: [:adapter, :service],
                  defaults: [
@@ -55,7 +55,7 @@ defmodule Spandex.Tracer do
                  ],
                  describe: [
                    adapter: "The third party adapter to use",
-                   tracer: "Don't set manually. This option is passed automatically.",
+                   trace_key: "Don't set manually. This option is passed automatically.",
                    sender:
                      "Once a trace is complete, it is sent using this module. Defaults to the `default_sender/0` of the selected adapter",
                    service: "The default service name to use for spans declared without a service",
@@ -115,16 +115,16 @@ defmodule Spandex.Tracer do
           opts = unquote(opts)
 
           name = unquote(name)
-          _ = unquote(__MODULE__).start_trace(name, opts)
+          unquote(__MODULE__).start_trace(name, opts)
           span_id = unquote(__MODULE__).current_span_id()
-          _ = Logger.metadata(span_id: span_id)
+          Logger.metadata(span_id: span_id)
 
           try do
             unquote(body)
           rescue
             exception ->
               stacktrace = System.stacktrace()
-              _ = unquote(__MODULE__).span_error(exception, stacktrace, opts)
+              unquote(__MODULE__).span_error(exception, stacktrace, opts)
               reraise exception, stacktrace
           after
             unquote(__MODULE__).finish_trace()
@@ -137,16 +137,16 @@ defmodule Spandex.Tracer do
         quote do
           opts = unquote(opts)
           name = unquote(name)
-          _ = unquote(__MODULE__).start_span(name, opts)
+          unquote(__MODULE__).start_span(name, opts)
           span_id = unquote(__MODULE__).current_span_id()
-          _ = Logger.metadata(span_id: span_id)
+          Logger.metadata(span_id: span_id)
 
           try do
             unquote(body)
           rescue
             exception ->
               stacktrace = System.stacktrace()
-              _ = unquote(__MODULE__).span_error(exception, stacktrace, opts)
+              unquote(__MODULE__).span_error(exception, stacktrace, opts)
               reraise exception, stacktrace
           after
             unquote(__MODULE__).finish_span()
@@ -229,7 +229,7 @@ defmodule Spandex.Tracer do
         |> Kernel.||([])
         |> Keyword.merge(opts || [])
         |> Optimal.validate!(@opts)
-        |> Keyword.put(:tracer, __MODULE__)
+        |> Keyword.put(:trace_key, __MODULE__)
       end
 
       defp config(opts, otp_app) do
@@ -255,7 +255,7 @@ defmodule Spandex.Tracer do
 
           opts
           |> Optimal.validate!(schema)
-          |> Keyword.put(:tracer, __MODULE__)
+          |> Keyword.put(:trace_key, __MODULE__)
           |> Keyword.put(:strategy, env[:strategy] || Spandex.Strategy.Pdict)
         end
       end
diff --git a/test/plug/add_context_test.exs b/test/plug/add_context_test.exs
index b0f92a0..b92d921 100644
--- a/test/plug/add_context_test.exs
+++ b/test/plug/add_context_test.exs
@@ -28,7 +28,7 @@ defmodule Spandex.Plug.AddContextTest do
           tracer_opts: []
         )
 
-      :ok = Tracer.finish_trace()
+      {:ok, _} = Tracer.finish_trace()
 
       %{resource: resource, http: http} = Spandex.Test.Util.find_span("request")
 
@@ -53,7 +53,7 @@ defmodule Spandex.Plug.AddContextTest do
       assert Keyword.fetch!(Logger.metadata(), :trace_id) == tid
       assert Keyword.fetch!(Logger.metadata(), :span_id) == expected_span.id
 
-      :ok = Tracer.finish_trace()
+      {:ok, _} = Tracer.finish_trace()
 
       %{trace_id: trace_id, type: type, http: http, resource: resource} = Spandex.Test.Util.find_span("request")
 
diff --git a/test/plug/end_trace_test.exs b/test/plug/end_trace_test.exs
index 366c5f2..99d397e 100644
--- a/test/plug/end_trace_test.exs
+++ b/test/plug/end_trace_test.exs
@@ -24,7 +24,7 @@ defmodule Spandex.Plug.EndTraceTest do
 
       assert Tracer.current_trace_id() == tid
 
-      :ok = Tracer.finish_trace()
+      {:ok, _} = Tracer.finish_trace()
     end
 
     test "updates top span and finish span, when we trace request for 200", %{
diff --git a/test/spandex_test.exs b/test/spandex_test.exs
index 85a77f8..aa3ebc8 100644
--- a/test/spandex_test.exs
+++ b/test/spandex_test.exs
@@ -92,7 +92,9 @@ defmodule Spandex.Test.SpandexTest do
     test "returns an error if invalid options are specified" do
       opts = @base_opts ++ @span_opts
       assert {:ok, %Trace{id: trace_id}} = Spandex.start_trace("root_span", opts)
+
       assert {:error, validation_errors} = Spandex.start_span("span_name", @base_opts ++ [type: "not an atom"])
+
       assert {:type, "must be of type :atom"} in validation_errors
     end
   end
@@ -148,7 +150,9 @@ defmodule Spandex.Test.SpandexTest do
     test "returns an error if invalid options are specified" do
       opts = @base_opts ++ @span_opts
       assert {:ok, %Trace{id: trace_id}} = Spandex.start_trace("root_span", opts)
+
       assert {:error, validation_errors} = Spandex.update_span(@base_opts ++ [type: "not an atom"])
+
       assert {:type, "must be of type :atom"} in validation_errors
     end
   end
@@ -222,7 +226,9 @@ defmodule Spandex.Test.SpandexTest do
     test "returns an error if invalid options are specified" do
       opts = @base_opts ++ @span_opts
       assert {:ok, %Trace{id: trace_id}} = Spandex.start_trace("root_span", opts)
+
       assert {:error, validation_errors} = Spandex.update_top_span(@base_opts ++ [type: "not an atom"])
+
       assert {:type, "must be of type :atom"} in validation_errors
     end
   end
@@ -239,6 +245,7 @@ defmodule Spandex.Test.SpandexTest do
       assert %Span{id: ^span_id, service: :updated_service} = Spandex.current_span(@base_opts)
 
       Spandex.finish_span(@base_opts)
+
       assert %Span{id: ^root_span_id, service: :updated_service} = Spandex.current_span(@base_opts)
     end
 
@@ -262,7 +269,9 @@ defmodule Spandex.Test.SpandexTest do
     test "returns an error if invalid options are specified" do
       opts = @base_opts ++ @span_opts
       assert {:ok, %Trace{id: trace_id}} = Spandex.start_trace("root_span", opts)
+
       assert {:error, validation_errors} = Spandex.update_all_spans(@base_opts ++ [type: "not an atom"])
+
       assert {:type, "must be of type :atom"} in validation_errors
     end
   end
@@ -274,7 +283,7 @@ defmodule Spandex.Test.SpandexTest do
       assert %Span{id: root_span_id} = Spandex.current_span(@base_opts)
       assert {:ok, %Span{id: span_id}} = Spandex.start_span("span_name", opts)
 
-      assert :ok = Spandex.finish_trace(@base_opts)
+      assert {:ok, _} = Spandex.finish_trace(@base_opts)
       spans = Util.sent_spans()
       assert length(spans) == 2
       assert Enum.any?(spans, fn span -> span.id == root_span_id end)
@@ -290,7 +299,7 @@ defmodule Spandex.Test.SpandexTest do
       assert %Span{id: root_span_id} = Spandex.current_span(@base_opts)
       assert {:ok, %Span{id: span_id}} = Spandex.start_span("span_name", opts)
 
-      assert :ok == Spandex.finish_trace(@base_opts ++ [sender: PdictSender])
+      assert {:ok, _} = Spandex.finish_trace(@base_opts ++ [sender: PdictSender])
       spans = Process.get(:spans)
       assert length(spans) == 2
       assert Enum.any?(spans, fn span -> span.id == root_span_id end)
@@ -306,7 +315,7 @@ defmodule Spandex.Test.SpandexTest do
       assert %Span{id: root_span_id} = Spandex.current_span(@base_opts)
       assert {:ok, %Span{id: span_id}} = Spandex.start_span("span_name", opts)
 
-      assert :ok = Spandex.finish_trace(@base_opts)
+      assert {:ok, _} = Spandex.finish_trace(@base_opts)
       spans = Util.sent_spans()
       assert length(spans) == 2
       assert Enum.all?(spans, fn span -> span.completion_time != nil end)
@@ -316,13 +325,17 @@ defmodule Spandex.Test.SpandexTest do
       now = :os.system_time(:nano_seconds)
       opts = @base_opts ++ @span_opts
       assert {:ok, %Trace{}} = Spandex.start_trace("root_span", opts)
+
       assert {:ok, %Span{id: span_id}} = Spandex.start_span("span_name", opts ++ [start: now - 10])
+
       assert {:ok, %Span{id: ^span_id}} = Spandex.update_span(@base_opts ++ [completion_time: now - 9])
+
       assert {:ok, %Span{id: ^span_id}} = Spandex.finish_span(@base_opts)
 
-      assert :ok = Spandex.finish_trace(@base_opts)
+      assert {:ok, _} = Spandex.finish_trace(@base_opts)
       spans = Util.sent_spans()
       assert length(spans) == 2
+
       assert Enum.any?(spans, fn span -> span.id == span_id && span.completion_time == now - 9 end)
     end
 
@@ -344,7 +357,9 @@ defmodule Spandex.Test.SpandexTest do
     test "returns an error if invalid options are specified" do
       opts = @base_opts ++ @span_opts
       assert {:ok, %Trace{id: trace_id}} = Spandex.start_trace("root_span", opts)
+
       assert {:error, validation_errors} = Spandex.finish_trace(@base_opts ++ [type: "not an atom"])
+
       assert {:type, "must be of type :atom"} in validation_errors
     end
   end
@@ -411,7 +426,9 @@ defmodule Spandex.Test.SpandexTest do
     test "returns an error if invalid options are specified" do
       opts = @base_opts ++ @span_opts
       assert {:ok, %Trace{id: trace_id}} = Spandex.start_trace("root_span", opts)
+
       assert {:error, validation_errors} = Spandex.finish_span(@base_opts ++ [type: "not an atom"])
+
       assert {:type, "must be of type :atom"} in validation_errors
     end
   end
@@ -461,7 +478,11 @@ defmodule Spandex.Test.SpandexTest do
       assert {:ok, %Trace{id: trace_id}} = Spandex.start_trace("root_span", opts)
 
       assert {:error, validation_errors} =
-               Spandex.span_error(@runtime_error, @fake_stacktrace, @base_opts ++ [type: "not an atom"])
+               Spandex.span_error(
+                 @runtime_error,
+                 @fake_stacktrace,
+                 @base_opts ++ [type: "not an atom"]
+               )
 
       assert {:type, "must be of type :atom"} in validation_errors
     end
@@ -565,7 +586,9 @@ defmodule Spandex.Test.SpandexTest do
   describe "Spandex.continue_trace_from_span/3" do
     test "returns a new trace based on a specified name and existing span" do
       existing_span = %Span{id: 456, trace_id: 123, name: "existing"}
+
       assert {:ok, %Trace{id: trace_id}} = Spandex.continue_trace_from_span("root_span", existing_span, @base_opts)
+
       assert trace_id != 123
       assert %Span{parent_id: 456, name: "root_span"} = Spandex.current_span(@base_opts)
     end
@@ -586,6 +609,7 @@ defmodule Spandex.Test.SpandexTest do
 
     test "returns an error if tracing is disabled" do
       existing_span = %Span{id: 456, trace_id: 123, name: "existing"}
+
       assert {:error, :disabled} == Spandex.continue_trace_from_span("root_span", existing_span, :disabled)
     end
 
@@ -593,7 +617,11 @@ defmodule Spandex.Test.SpandexTest do
       existing_span = %Span{id: 456, trace_id: 123, name: "existing"}
 
       assert {:error, validation_errors} =
-               Spandex.continue_trace_from_span("span_name", existing_span, @base_opts ++ [type: "not an atom"])
+               Spandex.continue_trace_from_span(
+                 "span_name",
+                 existing_span,
+                 @base_opts ++ [type: "not an atom"]
+               )
 
       assert {:type, "must be of type :atom"} in validation_errors
     end