1 files changed, 27 insertions, 0 deletions
diff --git a/activesupport/lib/active_support/core_ext/big_decimal/conversions.rb b/activesupport/lib/active_support/core_ext/big_decimal/conversions.rb
new file mode 100644
index 0000000000..f7f03f4d95
--- /dev/null
+++ b/activesupport/lib/active_support/core_ext/big_decimal/conversions.rb
@@ -0,0 +1,27 @@
+require 'bigdecimal'
+require 'yaml'
+
+class BigDecimal
+  YAML_TAG = 'tag:yaml.org,2002:float'
+  YAML_MAPPING = { 'Infinity' => '.Inf', '-Infinity' => '-.Inf', 'NaN' => '.NaN' }
+
+  yaml_as YAML_TAG
+
+  # This emits the number without any scientific notation.
+  # This is better than self.to_f.to_s since it doesn't lose precision.
+  #
+  # Note that reconstituting YAML floats to native floats may lose precision.
+  def to_yaml(opts = {})
+    YAML.quick_emit(nil, opts) do |out|
+      string = to_s
+      out.scalar(YAML_TAG, YAML_MAPPING[string] || string, :plain)
+    end
+  end
+
+  DEFAULT_STRING_FORMAT = 'F'
+  def to_formatted_s(format = DEFAULT_STRING_FORMAT)
+    _original_to_s(format)
+  end
+  alias_method :_original_to_s, :to_s
+  alias_method :to_s, :to_formatted_s
+end