diff --git a/lib/trailblazer/macro/nested.rb b/lib/trailblazer/macro/nested.rb
index d5de136..ecc60bf 100644
--- a/lib/trailblazer/macro/nested.rb
+++ b/lib/trailblazer/macro/nested.rb
@@ -104,7 +104,7 @@ def self.call_dynamic_nested_activity((ctx, flow_options), runner:, **circuit_op
 
         def self.compute_legacy_return_signal(return_signal)
           actual_semantic  = return_signal.to_h[:semantic]
-          applied_signal   = SUCCESS_SEMANTICS.include?(actual_semantic) ? Activity::Right : Activity::Left # TODO: we could also provide PassFast/FailFast.
+          _applied_signal   = SUCCESS_SEMANTICS.include?(actual_semantic) ? Activity::Right : Activity::Left # TODO: we could also provide PassFast/FailFast.
         end
 
         # This is used in Nested and Each where some tasks don't have a corresponding, hard-wired
diff --git a/test/docs/each_test.rb b/test/docs/each_test.rb
index ffb68df..32c63c9 100644
--- a/test/docs/each_test.rb
+++ b/test/docs/each_test.rb
@@ -711,7 +711,7 @@ class Validate < Trailblazer::Activity::Railway
     assert_equal Trailblazer::Developer::Introspect.find_path(activity, ["Each-1"])[0].id,                    "Each-1"
     assert_equal Trailblazer::Developer::Introspect.find_path(activity, ["Each/composers_for_each"])[0].id,   "Each/composers_for_each"
 
-    assert_match /Each\/\w+/, Trailblazer::Activity::Introspect::Nodes(activity).values[1].id # FIXME: this test sucks.
+    assert_match (/Each\/\w+/), Trailblazer::Activity::Introspect::Nodes(activity).values[1].id # FIXME: this test sucks.
   end
 end
 
@@ -740,7 +740,7 @@ def self.block
 
     ctx = {seq: [], dataset: [3,2,1]}
 
-    stack, signal, (ctx, _) = Trailblazer::Developer::Trace.invoke(activity, [ctx, {}])
+    stack, _signal, (_ctx, _) = Trailblazer::Developer::Trace.invoke(activity, [ctx, {}])
 
     output = Trailblazer::Developer::Trace::Present.(stack) do |trace_nodes:, **|
       {node_options: {trace_nodes[0] => {label: "<a-Each-b>"}}}
@@ -790,7 +790,7 @@ def self.block
     }
 
     # signal, (_ctx, _) = Trailblazer::Activity::TaskWrap.invoke(activity, [ctx])
-    signal, (_ctx, _) = Trailblazer::Developer.wtf?(activity, [ctx], exec_context: my_exec_context)
+    _signal, (_ctx, _) = Trailblazer::Developer.wtf?(activity, [ctx], exec_context: my_exec_context)
 
     assert_equal _ctx[:collected_from_each], ["1-0", "2-1", "3-2"]
   end
diff --git a/test/docs/guard_test.rb b/test/docs/guard_test.rb
index 45a4933..06b1fd1 100644
--- a/test/docs/guard_test.rb
+++ b/test/docs/guard_test.rb
@@ -27,7 +27,7 @@ def process(options, **)
   #---
   #- Guard inheritance
   class New < Create
-    step Policy::Guard( ->(options, current_user:, **) { current_user } ), override: true
+    step Policy::Guard( ->(options, current_user:, **) { current_user } ), replace: :"policy.default.eval"
   end
 
   it { assert_equal Trailblazer::Developer.railway(New), %{[>policy.default.eval,>process]} }
diff --git a/test/docs/model/find_test.rb b/test/docs/model/find_test.rb
index 29150d6..62a8529 100644
--- a/test/docs/model/find_test.rb
+++ b/test/docs/model/find_test.rb
@@ -29,7 +29,7 @@ class Update < Trailblazer::Activity::Railway
   #~ctx_to_result
   it do
     #:find_by_id-invoke
-    signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Update, params: {id: "1"}, seq: [])
+    _signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Update, params: {id: "1"}, seq: [])
     ctx[:model] #=> #<struct Song id=1>
     #:find_by_id-invoke end
 
@@ -37,14 +37,14 @@ class Update < Trailblazer::Activity::Railway
   end
 
   it do
-    signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Update, params: {short_id: nil}, seq: [])
+    _signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Update, params: {short_id: nil}, seq: [])
     assert_equal ctx[:model].inspect, %{nil}
   end
   #~ctx_to_result end
 
 # TODO: put this test somewhere else
   it "doesn't leak anything but {:model} to the outer world" do
-    signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Update, params: {id: "1"}, seq: [])
+    _signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Update, params: {id: "1"}, seq: [])
 
     assert_equal ctx.keys.inspect, %([:params, :seq, :model])
   end
@@ -75,7 +75,7 @@ class Update < Trailblazer::Activity::Railway
   #~ctx_to_result
   it do
     #:find_by_column-invoke
-    signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Update, params: {short_id: "1f396"}, seq: [])
+    _signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Update, params: {short_id: "1f396"}, seq: [])
     ctx[:model] #=> #<struct Song short_id="1f396">
     #:find_by_column-invoke end
 
@@ -83,7 +83,7 @@ class Update < Trailblazer::Activity::Railway
   end
 
   it do
-    signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Update, params: {short_id: nil}, seq: [])
+    _signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Update, params: {short_id: nil}, seq: [])
     assert_equal ctx[:model].inspect, %{nil}
   end
   #~ctx_to_result end
@@ -108,7 +108,7 @@ class Update < Trailblazer::Activity::Railway
   #~ctx_to_result
   it do
     #:params_key-invoke
-    signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Update, params: {slug: "1f396"}, seq: [])
+    _signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Update, params: {slug: "1f396"}, seq: [])
     ctx[:model] #=> #<struct Song id=2, id="1f396">
     #:params_key-invoke end
 
@@ -116,7 +116,7 @@ class Update < Trailblazer::Activity::Railway
   end
 
   it do
-    signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Update, params: {slug: nil}, seq: [])
+    _signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Update, params: {slug: nil}, seq: [])
     assert_equal ctx[:model].inspect, %{nil}
   end
   #~ctx_to_result end
@@ -146,7 +146,7 @@ class Update < Trailblazer::Activity::Railway
   #~ctx_to_result
   it do
     #:find_with-invoke
-    signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Update, params: {id: 2}, seq: [])
+    _signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Update, params: {id: 2}, seq: [])
     ctx[:model] #=> #<struct Song id=2>
     #:find_with-invoke end
 
@@ -154,7 +154,7 @@ class Update < Trailblazer::Activity::Railway
   end
 
   it do
-    signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Update, params: {id: nil}, seq: [])
+    _signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Update, params: {id: nil}, seq: [])
     assert_equal ctx[:model].inspect, %{nil}
   end
   #~ctx_to_result end
@@ -186,7 +186,7 @@ class Update < Trailblazer::Activity::Railway
   #~ctx_to_result
   it do
     #:id_from-invoke
-    signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Update, params: {song: {id: "1f396"}}, seq: [])
+    _signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Update, params: {song: {id: "1f396"}}, seq: [])
     ctx[:model] #=> #<struct Song id="1f396">
     #:id_from-invoke end
 
@@ -195,7 +195,7 @@ class Update < Trailblazer::Activity::Railway
   end
 
   it do
-    signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Update, params: {}, seq: [])
+    _signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Update, params: {}, seq: [])
 
     assert_equal ctx[:model].inspect, %{nil}
     assert_equal ctx[:seq].inspect, %([])
@@ -227,7 +227,7 @@ class Update < Trailblazer::Activity::Railway
   #~ctx_to_result
   it do
     #:find-ok
-    signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Update, {params: {id: 1}, seq: []})
+    _signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Update, {params: {id: 1}, seq: []})
     ctx[:model] #=> #<struct Song id=1, title="Roxanne">
     #:find-ok end
 
@@ -259,7 +259,7 @@ class Update < Trailblazer::Activity::Railway
   #~ctx_to_result
   it do
     #:show-ok
-    signal, (ctx, _) = Trailblazer::Developer.wtf?(Song::Activity::Update, [{params: {id: 1}, seq: []}])
+    _signal, (ctx, _) = Trailblazer::Developer.wtf?(Song::Activity::Update, [{params: {id: 1}, seq: []}])
     ctx[:model] #=> #<struct Song id=1, title="Roxanne">
     #:show-ok end
 
@@ -326,7 +326,7 @@ class Create < Trailblazer::Activity::Railway
   #~ctx_to_result
   it do
     #:new-invoke
-    signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Create, params: {}, seq: [])
+    _signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Create, params: {}, seq: [])
     ctx[:model] #=> #<struct Song id=1>
     #:new-invoke end
 
@@ -356,7 +356,7 @@ class Create < Trailblazer::Activity::Railway
   #~ctx_to_result
   it do
     #:build-invoke
-    signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Create, params: {}, seq: [])
+    _signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Create, params: {}, seq: [])
     ctx[:model] #=> #<struct Song id=1>
     #:build-invoke end
 
@@ -389,7 +389,7 @@ class Update < Trailblazer::Activity::Railway
     assert_invoke Song::Activity::Update, params: {id: nil}, terminus: :not_found
 
     #:not-found-invoke
-    signal, (ctx, _) = Trailblazer::Activity::TaskWrap.invoke(Song::Activity::Update, [{params: {id: nil}},{}])
+    signal, (_ctx, _) = Trailblazer::Activity::TaskWrap.invoke(Song::Activity::Update, [{params: {id: nil}},{}])
     puts signal #=> #<Trailblazer::Activity::End semantic=:not_found>
     #:not-found-invoke end
   end
diff --git a/test/docs/model_test.rb b/test/docs/model_test.rb
index 219fbdc..084c0ba 100644
--- a/test/docs/model_test.rb
+++ b/test/docs/model_test.rb
@@ -51,7 +51,7 @@ class Update < Trailblazer::Activity::Railway
   #~ctx_to_result
   it do
     #:create
-    signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Create, params: {}, seq: [])
+    _signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Create, params: {}, seq: [])
     puts ctx[:model] #=> #<struct Song id=nil, title=nil>
     #:create end
 
@@ -102,7 +102,7 @@ class Update < Trailblazer::Activity::Railway
   #~ctx_to_result
   it do
     #:update-with-find-by-key-ok
-    signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Update, params: {title: "Test"}, seq: [])
+    _signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Update, params: {title: "Test"}, seq: [])
     ctx[:model] #=> #<struct Song id=2, title="Test">
     #:update-with-find-by-key-ok end
 
@@ -111,7 +111,7 @@ class Update < Trailblazer::Activity::Railway
 
   it do
     #:key-title-fail
-    signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Update, params: {title: nil}, seq: [])
+    _signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Update, params: {title: nil}, seq: [])
 
     assert_equal ctx[:model].inspect, %{nil}
     #:key-title-fail end
@@ -138,7 +138,7 @@ class Update < Trailblazer::Activity::Railway
   #~ctx_to_result
   it do
     #:show-ok
-    signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Update, params: {id: 1}, seq: [])
+    _signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Update, params: {id: 1}, seq: [])
     ctx[:model] #=> #<struct Song id=1, title="Roxanne">
     #:show-ok end
 
@@ -166,14 +166,14 @@ class Hit < Song
     end
 
     #:di-model-class
-    signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Create, params: {}, :"model.class" => Hit, seq: [])
+    _signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Create, params: {}, :"model.class" => Hit, seq: [])
     #:di-model-class end
 
     assert_equal ctx[:model].inspect, %{#<struct #{Hit} id=nil, title=nil>}
 
   # inject all variables
     #:di-all
-    signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Create,
+    _signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Create,
       params:               {title: "Olympia"}, # some random variable.
       "model.class":        Hit,
       "model.action":       :find_by,
@@ -203,7 +203,7 @@ class Create < Trailblazer::Activity::Railway
   end
 
   it do
-    signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Create, params: {}, :"model.class" => Hit, seq: [])
+    _signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Create, params: {}, :"model.class" => Hit, seq: [])
 
     assert_equal ctx[:model].inspect, %{#<struct #{Hit} id=nil, title=nil>}
   end
@@ -224,7 +224,7 @@ class Create < Trailblazer::Operation
     end
     #:in end
 
-    signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Create, params: {}, my_id: 1, :"model.class" => Hit)
+    _signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Create, params: {}, my_id: 1, :"model.class" => Hit)
 
     assert_equal ctx[:model].inspect, %{#<struct #{Hit} id=1, title=nil>}
 =begin
@@ -233,7 +233,7 @@ class Create < Trailblazer::Operation
 #:in-call end
 =end
     end
-  end
+end
 end
 
 class Model404TerminusTest < Minitest::Spec
@@ -257,7 +257,7 @@ class Update < Trailblazer::Activity::Railway
     assert_invoke Song::Activity::Update, params: {id: nil}, terminus: :not_found
 
     #:not_found
-    signal, (ctx, _) = Trailblazer::Activity.(Song::Activity::Update, params: {id: nil})
+    signal, (_ctx, _) = Trailblazer::Activity.(Song::Activity::Update, params: {id: nil})
     puts signal #=> #<Trailblazer::Activity::End semantic=:not_found>
     #:not_found end
   end
@@ -286,7 +286,7 @@ class Update < Trailblazer::Activity::Railway
     assert_invoke Song::Activity::Update, params: {id: nil}, terminus: :not_found
 
     #:not_found
-    signal, (ctx, _) = Trailblazer::Activity::TaskWrap.invoke(Song::Activity::Update, [{params: {id: nil}},{}])
+    signal, (_ctx, _) = Trailblazer::Activity::TaskWrap.invoke(Song::Activity::Update, [{params: {id: nil}},{}])
     puts signal #=> #<Trailblazer::Activity::End semantic=:not_found>
     #:not_found end
   end
diff --git a/test/docs/nested_static_test.rb b/test/docs/nested_static_test.rb
index e224312..54c7d53 100644
--- a/test/docs/nested_static_test.rb
+++ b/test/docs/nested_static_test.rb
@@ -699,7 +699,7 @@ class NestedStrategyComplianceTest < Minitest::Spec
       ]
     )
     #:create-introspect end
-    assert_match /user_proc=encode_id3>/, output
+    assert_match (/user_proc=encode_id3>/), output
   end
 
   # TODO: test more options.
diff --git a/test/docs/pundit_test.rb b/test/docs/pundit_test.rb
index b263b7e..4804f64 100644
--- a/test/docs/pundit_test.rb
+++ b/test/docs/pundit_test.rb
@@ -61,7 +61,7 @@ class Edit < Trailblazer::Operation
   end
 
   class Update < Edit
-    step Policy::Pundit( MyPolicy, :new?, name: "first" ), override: true
+    step Policy::Pundit( MyPolicy, :new?, name: "first" ), replace: :"policy.first.eval"
   end
 
   it { assert_equal Trailblazer::Developer.railway(Edit), %{[>policy.first.eval,>policy.second.eval]} }
diff --git a/test/docs/rescue_test.rb b/test/docs/rescue_test.rb
index 4ab7a12..e603697 100644
--- a/test/docs/rescue_test.rb
+++ b/test/docs/rescue_test.rb
@@ -23,7 +23,7 @@ class NestedInsanity < Trailblazer::Operation
     fail ->(options, **) { options["outer-err"] = true }, id: "nested/failure"
   end
 
-  it { assert_match /\[>Rescue\/.{1,3},>nested/, Trailblazer::Developer.railway(NestedInsanity)  } # FIXME: better introspect tests for all id-generating macros.
+  it { assert_match (/\[>Rescue\/.{1,3},>nested/), Trailblazer::Developer.railway(NestedInsanity)  } # FIXME: better introspect tests for all id-generating macros.
   it { assert_equal NestedInsanity.().inspect("a", "y", "z", "b", "c", "e", "inner-err", "outer-err"), %{<Result:true [true, true, true, true, true, true, nil, nil] >} }
   it { assert_equal NestedInsanity.( "raise-y" => true).inspect("a", "y", "z", "b", "c", "e", "inner-err", "outer-err"), %{<Result:false [true, true, nil, nil, nil, nil, true, true] >} }
   it { assert_equal NestedInsanity.( "raise-a" => true).inspect("a", "y", "z", "b", "c", "e", "inner-err", "outer-err"), %{<Result:false [true, true, true, true, nil, nil, nil, true] >} }