Add initial project files

pkg/people/birthday.go

@@ -0,0 +1,37 @@
+package people
+
+import (
+	"encoding/json"
+	"time"
+)
+
+// Declaring birthday layout constant
+const birthdayLayout = "2006-01-02" // YYYY-MM-DD - is default birthday layout
+
+// Birthday is a custom encapsulation type for time.Time to handle birthdays
+// by decoding and encoding from and to JSON format
+type Birthday struct {
+	time.Time       // Embedding time.Time
+	err       error // Time parsing error
+}
+
+// UnmarshalJSON decodes a date text to time.Time object
+func (t *Birthday) UnmarshalJSON(bytes []byte) (err error) {
+	// 1. Decode the bytes into an int64
+	// 2. Parse the unix timestamp
+
+	// Is value quoted?
+	if rune(bytes[0]) == '"' || rune(bytes[0]) == '\'' {
+		bytes = bytes[1 : len(bytes)-1] // remove quotes
+	}
+
+	// Parse string to time.Time
+	t.Time, t.err = time.Parse(birthdayLayout, string(bytes))
+	t.err = err
+	return
+}
+
+// MarshalJSON encodes a time.Time object to date JSON text
+func (t Birthday) MarshalJSON() ([]byte, error) {
+	return json.Marshal(t.Time.Format(birthdayLayout))
+}