#469: Preserve hash additions in place

lib/fbe/overwrite.rb

@@ -40,14 +40,24 @@ def Fbe.overwrite(fact, property_or_hash, values = nil, fb: Fbe.fb, fid: '_id')
       before[k.to_s] = fact[k]
     end
     modified = false
+    missing = true
     property_or_hash.each do |k, vv|
       raise(Fbe::Error, "The value for #{k} is nil") if vv.nil?
       vv = [vv] unless vv.is_a?(Array)
+      missing = false unless before[k.to_s].nil?
       next if before[k.to_s] == vv
       before[k.to_s] = vv
       modified = true
     end
     return fact unless modified
+    if missing
+      before.slice(*property_or_hash.keys.map(&:to_s)).each do |k, vv|
+        vv.each do |v|
+          fact.public_send(:"#{k}=", v)
+        end
+      end
+      return
+    end
     id = fact[fid]&.first
     raise(Fbe::Error, "There is no #{fid} in the fact, cannot use Fbe.overwrite") if id.nil?
     raise(Fbe::Error, "No facts by #{fid} = #{id}") if fb.query("(eq #{fid} #{id})").delete!.zero?

test/fbe/test_overwrite.rb

@@ -88,6 +88,22 @@ def test_without_previous_property
     assert_equal(before, fbx.query('(eq bar 44)').each.first._id)
   end
 
+  def test_hash_without_previous_property
+    c = 0
+    fb =
+      Factbase::Pre.new(Factbase.new) do |f, _fbt|
+        f.pos = c
+        c += 1
+      end
+    f = fb.insert
+    f._id = 1
+    f.foo = 42
+    before = f.pos
+    Fbe.overwrite(f, { bar: 44 }, fb:)
+    found = fb.query('(eq bar 44)').each.first
+    assert_equal(before, found.pos)
+  end
+
   def test_safe_insert
     fb = Factbase.new
     first = fb.insert