From abf8a0f6fa9c880597f095a7b005089c3244f38a Mon Sep 17 00:00:00 2001
From: Serj Prikhodko <sergei.prikhodko@workato.com>
Date: Thu, 18 Jan 2024 16:06:25 +0100
Subject: [PATCH 1/6] Add a test-case for `Symbol#inspect`

---
 spec/unit/unparser_spec.rb | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/spec/unit/unparser_spec.rb b/spec/unit/unparser_spec.rb
index c979d1a9..05e147f3 100644
--- a/spec/unit/unparser_spec.rb
+++ b/spec/unit/unparser_spec.rb
@@ -390,6 +390,9 @@ def noop
         "false"
       end
     RUBY
+
+    # Test Symbol#inspect Ruby bug: https://bugs.ruby-lang.org/issues/18905
+    assert_source(':"8 >="')
   end
 
   describe 'corpus' do

From 73d94bd2140be3306f7a555ab7b53e8316649cb2 Mon Sep 17 00:00:00 2001
From: Serj Prikhodko <sergei.prikhodko@workato.com>
Date: Thu, 18 Jan 2024 16:31:38 +0100
Subject: [PATCH 2/6] Handle `Symbol#inspect` for Ruby `<3.2.0`

---
 lib/unparser/emitter/primitive.rb | 6 +++++-
 spec/unit/unparser_spec.rb        | 2 ++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/lib/unparser/emitter/primitive.rb b/lib/unparser/emitter/primitive.rb
index e173704d..d04eec48 100644
--- a/lib/unparser/emitter/primitive.rb
+++ b/lib/unparser/emitter/primitive.rb
@@ -15,7 +15,11 @@ class Inspect < self
       private
 
         def dispatch
-          write(value.inspect)
+          if RUBY_VERSION < '3.2' && node.type == :sym && value[-1] == '='
+            write(":#{value.name.inspect}")
+          else
+            write(value.inspect)
+          end
         end
 
       end # Inspect
diff --git a/spec/unit/unparser_spec.rb b/spec/unit/unparser_spec.rb
index 05e147f3..43d6867a 100644
--- a/spec/unit/unparser_spec.rb
+++ b/spec/unit/unparser_spec.rb
@@ -392,6 +392,8 @@ def noop
     RUBY
 
     # Test Symbol#inspect Ruby bug: https://bugs.ruby-lang.org/issues/18905
+    assert_source(':"@="')
+    assert_source(':"$$$$="')
     assert_source(':"8 >="')
   end
 

From 4a0ac3e2e482c41a635daf2284c6eb81e277896f Mon Sep 17 00:00:00 2001
From: Serj Prikhodko <sergei.prikhodko@workato.com>
Date: Thu, 18 Jan 2024 16:33:00 +0100
Subject: [PATCH 3/6] Extract dedicated `Symbol` emitter

---
 lib/unparser/emitter/primitive.rb | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/lib/unparser/emitter/primitive.rb b/lib/unparser/emitter/primitive.rb
index d04eec48..f26a9243 100644
--- a/lib/unparser/emitter/primitive.rb
+++ b/lib/unparser/emitter/primitive.rb
@@ -10,19 +10,31 @@ class Primitive < self
       # Emitter for primitives based on Object#inspect
       class Inspect < self
 
-        handle :sym, :str
+        handle :str
 
       private
 
         def dispatch
-          if RUBY_VERSION < '3.2' && node.type == :sym && value[-1] == '='
+          write(value.inspect)
+        end
+
+      end # Inspect
+
+      class Symbol < self
+
+        handle :sym
+
+        private
+
+        def dispatch
+          if RUBY_VERSION < '3.2' && value[-1] == '='
             write(":#{value.name.inspect}")
           else
             write(value.inspect)
           end
         end
 
-      end # Inspect
+      end # Symbol
 
       # Emitter for complex literals
       class Complex < self

From c90147dcda082540bcd248fdd69b2f719017b5eb Mon Sep 17 00:00:00 2001
From: Serj Prikhodko <sergei.prikhodko@workato.com>
Date: Thu, 18 Jan 2024 17:23:56 +0100
Subject: [PATCH 4/6] Disable mutant on `Symbol#dispatch` as it depends on Ruby
 version and would fail on CI.

---
 lib/unparser/emitter/primitive.rb | 1 +
 1 file changed, 1 insertion(+)

diff --git a/lib/unparser/emitter/primitive.rb b/lib/unparser/emitter/primitive.rb
index f26a9243..8c75c77b 100644
--- a/lib/unparser/emitter/primitive.rb
+++ b/lib/unparser/emitter/primitive.rb
@@ -26,6 +26,7 @@ class Symbol < self
 
         private
 
+        # mutant:disable
         def dispatch
           if RUBY_VERSION < '3.2' && value[-1] == '='
             write(":#{value.name.inspect}")

From d8c0b59297f0319a9469a287c2e36b8bd04c0496 Mon Sep 17 00:00:00 2001
From: Serj Prikhodko <sergei.prikhodko@workato.com>
Date: Thu, 18 Jan 2024 20:13:32 +0100
Subject: [PATCH 5/6] Improve symbol detection logic

---
 lib/unparser/emitter/primitive.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/unparser/emitter/primitive.rb b/lib/unparser/emitter/primitive.rb
index 8c75c77b..57f42ec8 100644
--- a/lib/unparser/emitter/primitive.rb
+++ b/lib/unparser/emitter/primitive.rb
@@ -28,7 +28,7 @@ class Symbol < self
 
         # mutant:disable
         def dispatch
-          if RUBY_VERSION < '3.2' && value[-1] == '='
+          if RUBY_VERSION < '3.2' && value.match?(/=\z/)
             write(":#{value.name.inspect}")
           else
             write(value.inspect)

From 03c572231c8b69c82d00e2e6315a0f695bb6e79b Mon Sep 17 00:00:00 2001
From: Serj Prikhodko <sergei.prikhodko@workato.com>
Date: Tue, 23 Jan 2024 10:23:46 +0100
Subject: [PATCH 6/6] Replace `regexp` check with `parse`

---
 lib/unparser/emitter/primitive.rb | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/lib/unparser/emitter/primitive.rb b/lib/unparser/emitter/primitive.rb
index 57f42ec8..ec17b16b 100644
--- a/lib/unparser/emitter/primitive.rb
+++ b/lib/unparser/emitter/primitive.rb
@@ -28,13 +28,22 @@ class Symbol < self
 
         # mutant:disable
         def dispatch
-          if RUBY_VERSION < '3.2' && value.match?(/=\z/)
+          if inspect_breaks_parsing?
             write(":#{value.name.inspect}")
           else
             write(value.inspect)
           end
         end
 
+        # mutant:disable
+        def inspect_breaks_parsing?
+          return false unless RUBY_VERSION < '3.2.'
+
+          Unparser.parse(value.inspect)
+          false
+        rescue Parser::SyntaxError
+          true
+        end
       end # Symbol
 
       # Emitter for complex literals