feat: handle timestamps as strings in YAML parsing (#669)

Signed-off-by: yxxhero <aiopsclub@163.com>

Author: yxxhero

io.go

@@ -70,12 +70,32 @@ func nodesFromReader(reader io.Reader) ([]yaml.Node, error) {
 			break
 		}
 		if len(node.Content[0].Content) > 0 {
+			replaceTimestamp(&node)
 			nodes = append(nodes, node)
 		}
 	}
 	return nodes, nil
 }
 
+// A custom unmarshal is needed because go-yaml parse "YYYY-MM-DD" as a full
+// timestamp, writing YYYY-MM-DD HH:MM:SS +0000 UTC when encoding, so we are
+// going to treat timestamps as strings.
+// See: https://github.com/go-yaml/yaml/issues/770
+
+func replaceTimestamp(n *yaml.Node) {
+	if len(n.Content) == 0 {
+		return
+	}
+	for _, innerNode := range n.Content {
+		if innerNode.Tag == "!!map" {
+			replaceTimestamp(innerNode)
+		}
+		if innerNode.Tag == "!!timestamp" {
+			innerNode.Tag = "!!str"
+		}
+	}
+}
+
 func Output(output io.Writer, format string, nodes []yaml.Node) error {
 	for i, node := range nodes {
 		var v interface{}

vals_test.go

@@ -149,3 +149,37 @@ func TestEvalNodesWithDictionaries(t *testing.T) {
 
 	require.Equal(t, expected, buf.String())
 }
+
+func TestEvalNodesWithTime(t *testing.T) {
+	var yamlDocs = `
+date: 2025-01-01
+datetime: 2025-01-01T12:34:56Z
+datetime_millis: 2025-01-01T12:34:56.789Z
+datetime_offset: 2025-01-01T12:34:56+01:00
+`
+
+	var expected = `date: "2025-01-01"
+datetime: "2025-01-01T12:34:56Z"
+datetime_millis: "2025-01-01T12:34:56.789Z"
+datetime_offset: "2025-01-01T12:34:56+01:00"
+`
+
+	tmpFile, err := os.CreateTemp("", "secrets.yaml")
+	defer os.Remove(tmpFile.Name())
+	require.NoError(t, err)
+
+	_, err = tmpFile.WriteString(yamlDocs)
+	require.NoError(t, err)
+
+	input, err := Inputs(tmpFile.Name())
+	require.NoError(t, err)
+
+	nodes, err := EvalNodes(input, Options{})
+	require.NoError(t, err)
+	buf := new(strings.Builder)
+
+	err = Output(buf, "", nodes)
+	require.NoError(t, err)
+
+	require.Equal(t, expected, buf.String())
+}