Fix line number on non-newline terminated string

lib/rbs/buffer.rb

@@ -25,6 +25,11 @@ def ranges
             @ranges << range
             offset += size
           end
+
+          if !content.end_with?("\n") && content.size > 0
+            @ranges[-1] = @ranges[-1].begin...(@ranges[-1].end+1)
+          end
+
           @ranges
         end
     end

test/rbs/buffer_test.rb

@@ -37,4 +37,34 @@ def test_buffer
 
     assert_equal 8, buffer.last_position
   end
+
+  def test_buffer_with_no_eol
+    buffer = Buffer.new(name: Pathname("foo.rbs"), content: "123\nabc")
+
+    assert_equal ["123\n", "abc"], buffer.lines
+    assert_equal [0...4, 4...8], buffer.ranges
+
+    assert_equal [1, 0], buffer.pos_to_loc(0)
+    assert_equal [1, 1], buffer.pos_to_loc(1)
+    assert_equal [1, 2], buffer.pos_to_loc(2)
+    assert_equal [1, 3], buffer.pos_to_loc(3)
+    assert_equal [2, 0], buffer.pos_to_loc(4)
+    assert_equal [2, 1], buffer.pos_to_loc(5)
+    assert_equal [2, 2], buffer.pos_to_loc(6)
+    assert_equal [2, 3], buffer.pos_to_loc(7)
+
+    assert_equal 0, buffer.loc_to_pos([1, 0])
+    assert_equal 1, buffer.loc_to_pos([1, 1])
+    assert_equal 2, buffer.loc_to_pos([1, 2])
+    assert_equal 3, buffer.loc_to_pos([1, 3])
+    assert_equal 4, buffer.loc_to_pos([2, 0])
+    assert_equal 5, buffer.loc_to_pos([2, 1])
+    assert_equal 6, buffer.loc_to_pos([2, 2])
+    assert_equal 7, buffer.loc_to_pos([2, 3])
+
+    assert_equal "123", buffer.content[buffer.loc_to_pos([1,0])...buffer.loc_to_pos([1,3])]
+    assert_equal "123\n", buffer.content[buffer.loc_to_pos([1,0])...buffer.loc_to_pos([2,0])]
+
+    assert_equal 7, buffer.last_position
+  end
 end