Fix a narrowing bug for a nested ivar

Author: mame

lib/typeprof/core/env.rb

@@ -330,7 +330,11 @@ def pop_ivar_narrowing(name)
 
     def apply_ivar_narrowing(genv, node, name, vtx)
       if @ivar_narrowings[name] && !@ivar_narrowings[name].empty?
-        return @ivar_narrowings[name].last.narrow(genv, node, vtx)
+        # Apply all accumulated narrowings in order
+        @ivar_narrowings[name].each do |narrowing|
+          vtx = narrowing.narrow(genv, node, vtx)
+        end
+        return vtx
       end
       vtx
     end

scenario/flow/ivar3.rb

@@ -0,0 +1,35 @@
+## update
+class Foo
+  def initialize(x)
+    @x = x
+  end
+
+  def accept_int(x) = nil
+  def accept_str(x) = nil
+  def accept_nil(x) = nil
+
+  def foo
+    if @x
+      if @x.is_a?(String)
+        accept_str(@x)
+      else
+        accept_int(@x)
+      end
+    else
+      accept_nil(@x)
+    end
+  end
+end
+
+Foo.new(1)
+Foo.new("")
+Foo.new(nil)
+
+## assert
+class Foo
+  def initialize: ((Integer | String)?) -> (Integer | String)?
+  def accept_int: (Integer) -> nil
+  def accept_str: (String) -> nil
+  def accept_nil: (nil) -> nil
+  def foo: -> nil
+end