Address PR feedback: sigil fix and cleanup

- Change `.capture_flamegraph?` to `#capture_flamegraph?` (instance method)
- Remove temp directory setup (now handled globally via spec_helper)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: dpep

spec/singed/middleware_spec.rb

@@ -1,7 +1,5 @@
 # frozen_string_literal: true
 
-require "tmpdir"
-
 describe Singed::RackMiddleware do
   subject do
     instance.call(env)
@@ -12,31 +10,33 @@
   let(:env) { Rack::MockRequest.env_for("/", headers) }
   let(:headers) { {} }
 
-  before do
-    allow_any_instance_of(Singed::Flamegraph).to receive(:open)
-    Singed.output_directory = Dir.mktmpdir("singed-spec")
-  end
-
   it "returns a proper rack response" do
     linted_app = Rack::Lint.new(instance)
     expect { linted_app.call(env) }.not_to raise_error
   end
 
-  it "does not capture a flamegraph by default" do
-    expect(instance).not_to receive(:flamegraph)
-    subject
+  it "passes through the app response unchanged" do
+    expect(subject).to eq([200, {"content-type" => "text/plain"}, ["OK"]])
   end
 
   context "when enabled" do
-    before { allow(instance).to receive(:capture_flamegraph?).and_return(true) }
+    before do
+      allow_any_instance_of(Singed::Flamegraph).to receive(:open)
+      allow(instance).to receive(:capture_flamegraph?).and_return(true)
+    end
 
     it "captures a flamegraph" do
       expect(instance).to receive(:flamegraph).and_call_original
       subject
     end
+
+    it "returns a proper rack response" do
+      linted_app = Rack::Lint.new(instance)
+      expect { linted_app.call(env) }.not_to raise_error
+    end
   end
 
-  describe ".capture_flamegraph?" do
+  describe "#capture_flamegraph?" do
     subject { instance.capture_flamegraph?(env) }
 
     it { is_expected.to be false }
@@ -46,5 +46,34 @@
 
       it { is_expected.to be true }
     end
+
+    context "when SINGED_MIDDLEWARE_ALWAYS_CAPTURE env var is set" do
+      around do |example|
+        original = ENV["SINGED_MIDDLEWARE_ALWAYS_CAPTURE"]
+        described_class.remove_instance_variable(:@always_capture) if described_class.instance_variable_defined?(:@always_capture)
+        example.run
+      ensure
+        if original.nil?
+          ENV.delete("SINGED_MIDDLEWARE_ALWAYS_CAPTURE")
+        else
+          ENV["SINGED_MIDDLEWARE_ALWAYS_CAPTURE"] = original
+        end
+        described_class.remove_instance_variable(:@always_capture) if described_class.instance_variable_defined?(:@always_capture)
+      end
+
+      %w[true 1 yes].each do |truthy_value|
+        context "when SINGED_MIDDLEWARE_ALWAYS_CAPTURE=#{truthy_value}" do
+          before { ENV["SINGED_MIDDLEWARE_ALWAYS_CAPTURE"] = truthy_value }
+
+          it { is_expected.to be true }
+        end
+      end
+
+      context "when SINGED_MIDDLEWARE_ALWAYS_CAPTURE=false" do
+        before { ENV["SINGED_MIDDLEWARE_ALWAYS_CAPTURE"] = "false" }
+
+        it { is_expected.to be false }
+      end
+    end
   end
 end