Merge pull request #90 from ufirstgroup/canonical-timestamp-format

encode timestamp with canonical format (iso8601) see #87

.github/workflows/ci.yaml

@@ -1,4 +1,5 @@
-name: CI
+name: CI checks
+
 on:
   push:
     branches: [main]

.github/workflows/test.yaml

@@ -1,4 +1,4 @@
-name: Run tests on versions according to .tool-versions
+name: mix test for [version matrix]
 
 on:
   push:
@@ -11,9 +11,17 @@ jobs:
     runs-on: ubuntu-latest
     name: Test - OTP ${{matrix.otp}} / Elixir ${{matrix.elixir}}
     strategy:
+      # see https://hexdocs.pm/elixir/1.14.0-rc.0/compatibility-and-deprecations.html#compatibility-between-elixir-and-erlang-otp
       matrix:
-        elixir: [1.11.x, 1.12.x]
-        otp: [22.x, 23.x, 24.x]
+        elixir: ['1.11.x', '1.12.x', '1.13.x']
+        otp: ['22.x', '23.x', '24.x']
+        include:
+          - elixir: '1.10.x'
+            otp: '22.x'
+          - elixir: '>1.10.3'
+            otp: '23.x'
+          - elixir: '1.13.4'
+            otp: '25.x'
     steps:
       - uses: actions/checkout@v1.0.0
 

CHANGELOG.md

@@ -9,6 +9,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 ### Changed
 
 - use `Enum.map_join/3` indead of `Enum.map/2` and `Enum.join/2` as it's more efficient according to credo recommendations
+- fix #87 - change the serialization of timestamps to use the canonical (iso8601) format, i.e. before: `2022-07-31 14:48:48.000000000 Z` and now: `"2022-07-31T14:48:48Z"`
 
 ## [2.0.0] - 2021-04-02
 

lib/ymlr/encoder.ex

@@ -73,10 +73,10 @@ defmodule Ymlr.Encoder do
     "{}"
   end
 
-  defp encode_as_io_list(%Date{} = data, _), do: Calendar.strftime(data, "%Y-%m-%d")
+  defp encode_as_io_list(%Date{} = data, _), do: Date.to_iso8601(data)
 
   defp encode_as_io_list(%DateTime{} = data, _) do
-    data |> DateTime.shift_zone!("Etc/UTC") |> Calendar.strftime("%Y-%m-%d %H:%M:%S.000000000 Z")
+    data |> DateTime.shift_zone!("Etc/UTC") |> DateTime.to_iso8601()
   end
 
   defp encode_as_io_list(data, level) when is_map(data) do

lib/ymlr/encoder_test.exs

@@ -199,7 +199,11 @@ defmodule Ymlr.EncoderTest do
     end
 
     test "datetime" do
-      assert MUT.to_s!(DateTime.from_naive!(~N[2016-05-24 13:26:08.003], "Etc/UTC")) == "2016-05-24 13:26:08.000000000 Z"
+      assert MUT.to_s!(~U[2016-05-24 13:26:08Z])      == "2016-05-24T13:26:08Z"
+      assert MUT.to_s!(~U[2016-05-24 13:26:08.1Z])    == "2016-05-24T13:26:08.1Z"
+      assert MUT.to_s!(~U[2016-05-24 13:26:08.02Z])   == "2016-05-24T13:26:08.02Z"
+      assert MUT.to_s!(~U[2016-05-24 13:26:08.003Z])  == "2016-05-24T13:26:08.003Z"
+      assert MUT.to_s!(~U[2016-05-24 13:26:08.0004Z]) == "2016-05-24T13:26:08.0004Z"
     end
   end
 

mix.exs

@@ -9,7 +9,7 @@ defmodule Ymlr.MixProject do
       app: :ymlr,
       description: "A YAML encoder for Elixir",
       version: @version,
-      elixir: "~> 1.11",
+      elixir: "~> 1.10",
       deps: deps(),
       dialyzer: dialyzer(),
       package: package(),