Add FromString method

id.go

@@ -126,6 +126,13 @@ func New() ID {
 	return id
 }
 
+// FromString reads an ID from its string representation
+func FromString(id string) (ID, error) {
+	i := &ID{}
+	err := i.UnmarshalText([]byte(id))
+	return *i, err
+}
+
 // String returns a base32 hex lowercased with no padding representation of the id (char set is 0-9, a-v).
 func (id ID) String() string {
 	text, _ := id.MarshalText()

id_test.go

@@ -82,6 +82,18 @@ func TestIDString(t *testing.T) {
 	assert.Equal(t, "9m4e2mr0ui3e8a215n4g", id.String())
 }
 
+func TestFromString(t *testing.T) {
+	id, err := FromString("9m4e2mr0ui3e8a215n4g")
+	assert.NoError(t, err)
+	assert.Equal(t, ID{0x4d, 0x88, 0xe1, 0x5b, 0x60, 0xf4, 0x86, 0xe4, 0x28, 0x41, 0x2d, 0xc9}, id)
+}
+
+func TestFromStringInvalid(t *testing.T) {
+	id, err := FromString("invalid")
+	assert.EqualError(t, err, "invalid ID")
+	assert.Equal(t, ID{}, id)
+}
+
 type jsonType struct {
 	ID *ID
 }