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Don't use length() as it's expensive #1021

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Merged
jeffkreeftmeijer merged 1 commit into from
Dec 8, 2025
Merged

Don't use length() as it's expensive #1021

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2 changes: 1 addition & 1 deletion lib/appsignal/check_in/scheduler.ex
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Original file line number Diff line number Diff line change
Expand Up @@ -120,7 +120,7 @@ defmodule Appsignal.CheckIn.Scheduler do
end

@impl true
def terminate(_reason, %{events: events}) when length(events) > 0 do
def terminate(_reason, %{events: [_ | _] = events}) do
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@unflxw unflxw Dec 9, 2025

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Sorry, catching up on this as I was away. Thank you for looking into these warnings!

This is of course subjective, but I find this quite hard to read. Consider when events != [] instead? It should still be O(1), and it's what Enum.empty?/1, the alternative recommended by the Credo warning, does under the hood.

# If any events are stored, attempt to transmit them before the
# process is terminated.
handle_continue({:transmit, events}, initial_state())
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10 changes: 5 additions & 5 deletions test/appsignal/error_test.exs
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Original file line number Diff line number Diff line change
Expand Up @@ -21,7 +21,7 @@ defmodule Appsignal.ErrorTest do
test "format's the error's stack trace", %{metadata: metadata} do
{_name, _message, stack} = metadata
assert is_list(stack)
assert length(stack) > 0
refute Enum.empty?(stack)
assert Enum.all?(stack, &is_binary(&1))
end
end
Expand All @@ -46,7 +46,7 @@ defmodule Appsignal.ErrorTest do
test "format's the error's stack trace", %{metadata: metadata} do
{_name, _message, stack} = metadata
assert is_list(stack)
assert length(stack) > 0
refute Enum.empty?(stack)
assert Enum.all?(stack, &is_binary(&1))
end
end
Expand All @@ -73,7 +73,7 @@ defmodule Appsignal.ErrorTest do
test "format's the error's stack trace", %{metadata: metadata} do
{_name, _message, stack} = metadata
assert is_list(stack)
assert length(stack) > 0
refute Enum.empty?(stack)
assert Enum.all?(stack, &is_binary(&1))
end
end
Expand Down Expand Up @@ -101,7 +101,7 @@ defmodule Appsignal.ErrorTest do
test "format's the error's stack trace", %{metadata: metadata} do
{_name, _message, stack} = metadata
assert is_list(stack)
assert length(stack) > 0
refute Enum.empty?(stack)
assert Enum.all?(stack, &is_binary(&1))
end
end
Expand All @@ -126,7 +126,7 @@ defmodule Appsignal.ErrorTest do
test "format's the error's stack trace", %{metadata: metadata} do
{_name, _message, stack} = metadata
assert is_list(stack)
assert length(stack) > 0
refute Enum.empty?(stack)
assert Enum.all?(stack, &is_binary(&1))
end
end
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2 changes: 1 addition & 1 deletion test/appsignal/stacktrace_test.exs
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Expand Up @@ -14,7 +14,7 @@ defmodule Appsignal.StacktraceTest do
end

test "does not return an empty list", %{stack: stack} do
assert length(stack) > 0
refute Enum.empty?(stack)
end

test "returns a stacktrace containing the error", %{
Expand Down
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