From a58c6ff73281a8d48851fbd6480252b8d1dcda5a Mon Sep 17 00:00:00 2001
From: Daniel Gollahon <daniel@cognitohq.com>
Date: Sat, 5 Sep 2020 21:28:14 -0600
Subject: [PATCH] Add block-pass mutations

- Adds `foo(&method(:bar))` -> `foo(&public_method(:bar))` and similar mutations.
---
 Changelog.md                          |  1 +
 lib/mutant.rb                         |  1 +
 lib/mutant/mutator/node/block_pass.rb | 20 ++++++++++++++++++++
 lib/mutant/mutator/node/noop.rb       |  2 +-
 meta/block.rb                         |  7 +++++++
 meta/block_pass.rb                    | 17 +++++++++++++++++
 meta/send.rb                          |  4 ++++
 7 files changed, 51 insertions(+), 1 deletion(-)
 create mode 100644 lib/mutant/mutator/node/block_pass.rb

diff --git a/Changelog.md b/Changelog.md
index 69685bb88..8d05affa2 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -1,5 +1,6 @@
 # Unreleased
 
+* Add block-pass mutations (`foo(&method(:bar))` -> `foo(&public_method(:bar))`) [#1047](https://github.com/mbj/mutant/pull/1047)
 * Add new mutation of `Array(foo)` -> `[foo]` [#1043](https://github.com/mbj/mutant/pull/1043)
 * Add new mutation to mutate dynamic sends to static sends ({`foo.__send__(:bar)`, `foo.send(:bar)`, `foo.public_send(:bar)`} -> `foo.bar`) [#1040](https://github.com/mbj/mutant/pull/1040)
 
diff --git a/lib/mutant.rb b/lib/mutant.rb
index 37d4f7681..7b2133f71 100644
--- a/lib/mutant.rb
+++ b/lib/mutant.rb
@@ -120,6 +120,7 @@ module Mutant
 require 'mutant/mutator/node/masgn'
 require 'mutant/mutator/node/return'
 require 'mutant/mutator/node/block'
+require 'mutant/mutator/node/block_pass'
 require 'mutant/mutator/node/if'
 require 'mutant/mutator/node/case'
 require 'mutant/mutator/node/splat'
diff --git a/lib/mutant/mutator/node/block_pass.rb b/lib/mutant/mutator/node/block_pass.rb
new file mode 100644
index 000000000..f5005e474
--- /dev/null
+++ b/lib/mutant/mutator/node/block_pass.rb
@@ -0,0 +1,20 @@
+# frozen_string_literal: true
+
+module Mutant
+  class Mutator
+    class Node
+      class BlockPass < self
+
+        handle(:block_pass)
+
+        children :argument
+
+      private
+
+        def dispatch
+          emit_argument_mutations
+        end
+      end # Block
+    end # Node
+  end # Mutator
+end # Mutant
diff --git a/lib/mutant/mutator/node/noop.rb b/lib/mutant/mutator/node/noop.rb
index a56b8a0ce..6bc7fb1a0 100644
--- a/lib/mutant/mutator/node/noop.rb
+++ b/lib/mutant/mutator/node/noop.rb
@@ -7,7 +7,7 @@ class Node
       # Mutation emitter to handle noop nodes
       class Noop < self
 
-        handle(:__ENCODING__, :block_pass, :cbase, :lambda)
+        handle(:__ENCODING__, :cbase, :lambda)
 
       private
 
diff --git a/meta/block.rb b/meta/block.rb
index df05b8ea7..2db4d39c6 100644
--- a/meta/block.rb
+++ b/meta/block.rb
@@ -184,6 +184,9 @@
   mutation 'foo.baz { }'
   mutation 'foo(&:bar).baz'
   mutation 'self.baz {}'
+  mutation 'foo(&nil).baz {}'
+  mutation 'foo(&self).baz {}'
+  mutation 'foo(&:bar__mutant__).baz {}'
 end
 
 Mutant::Meta::Example.add :block do
@@ -196,4 +199,8 @@
   mutation 'foo.baz { }'
   mutation 'self.baz { }'
   mutation 'foo(nil, &:bar).baz'
+
+  mutation 'foo(nil, &self).baz {}'
+  mutation 'foo(nil, &nil).baz {}'
+  mutation 'foo(nil, &:bar__mutant__).baz {}'
 end
diff --git a/meta/block_pass.rb b/meta/block_pass.rb
index e23306852..6bbbb729e 100644
--- a/meta/block_pass.rb
+++ b/meta/block_pass.rb
@@ -5,4 +5,21 @@
 
   singleton_mutations
   mutation 'foo'
+  mutation 'foo(&nil)'
+  mutation 'foo(&self)'
+end
+
+Mutant::Meta::Example.add :block_pass do
+  source 'foo(&method(:bar))'
+
+  singleton_mutations
+  mutation 'foo'
+  mutation 'foo(&nil)'
+  mutation 'foo(&self)'
+  mutation 'foo(&method)'
+  mutation 'foo(&method(nil))'
+  mutation 'foo(&method(self))'
+  mutation 'foo(&method(:bar__mutant__))'
+  mutation 'foo(&public_method(:bar))'
+  mutation 'foo(&:bar)'
 end
diff --git a/meta/send.rb b/meta/send.rb
index 6f0af5dcc..30668fbb4 100644
--- a/meta/send.rb
+++ b/meta/send.rb
@@ -340,6 +340,8 @@
   source 'foo.public_send(:bar, 1, two: true, **kwargs, &block)'
 
   singleton_mutations
+  mutation 'foo.public_send(:bar, 1, { two: true, **kwargs }, &nil)'
+  mutation 'foo.public_send(:bar, 1, { two: true, **kwargs }, &self)'
   mutation 'foo.bar(1, two: true, **kwargs, &block)'
   mutation 'foo'
   mutation 'self.public_send(:bar, 1, { two: true, **kwargs }, &block)'
@@ -422,6 +424,8 @@
 
   singleton_mutations
   mutation 'foo'
+  mutation 'foo(&nil)'
+  mutation 'foo(&self)'
 end
 
 Mutant::Meta::Example.add :send do