Remove colon from Hash key symbols

lib/debug/variable_inspector.rb

@@ -18,7 +18,7 @@ def named_members_of(obj)
       return [] if NaiveString === obj
 
       members = case obj
-      when Hash then obj.map { |k, v| Variable.new(name: value_inspect(k), value: v) }
+      when Hash then obj.map { |k, v| Variable.new(name: inspect_hash_key(k), value: v) }
       when Struct then obj.members.map { |name| Variable.new(name: name, value: obj[name]) }
       when String
         members = [
@@ -50,6 +50,13 @@ def named_members_of(obj)
 
     private
 
+    def inspect_hash_key(key)
+      # Special-case for symbols so debugger UIs render `a: 1` instead of two colons like `:a: 1`
+      return key.to_s if key.is_a?(Symbol)
+
+      value_inspect(key)
+    end
+
     def value_inspect(obj, short: true)
       self.class.value_inspect(obj, short: short)
     end

test/debug/variable_inspector_test.rb

@@ -48,7 +48,7 @@ def test_named_members_of_hash
 
       expected = [
         Variable.internal(name: '#class', value: Hash),
-        Variable.new(name: ':sym', value: "has Symbol key"),
+        Variable.new(name: 'sym', value: "has Symbol key"),
         Variable.new(name: '"str"', value: "has String key"),
         Variable.new(name: '1', value: "has Integer key"),
       ]