From faac776ca466d7aa57e5105470dc822334f13eab Mon Sep 17 00:00:00 2001
From: Aaron Lindsay <aaron@aclindsay.com>
Date: Mon, 17 Apr 2017 20:11:53 -0400
Subject: [PATCH] Add Currency type

---
 types.go      | 52 +++++++++++++++++++++++++++++++++++++++
 types_test.go | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 120 insertions(+)

diff --git a/types.go b/types.go
index cbb27b0..ff5fda2 100644
--- a/types.go
+++ b/types.go
@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"github.com/aclindsa/go/src/encoding/xml"
+	"golang.org/x/text/currency"
 	"math/big"
 	"regexp"
 	"strconv"
@@ -321,3 +322,54 @@ func RandomUID() (*UID, error) {
 	uid := UID(fmt.Sprintf("%08x-%04x-%04x-%04x-%012x", uidbytes[:4], uidbytes[4:6], uidbytes[6:8], uidbytes[8:10], uidbytes[10:]))
 	return &uid, nil
 }
+
+// CurrSymbol represents an ISO-4217 currency
+type CurrSymbol struct {
+	currency.Unit
+}
+
+// UnmarshalXML handles unmarshalling a CurrSymbol from an SGML/XML string.
+// Leading and trailing whitespace is ignored.
+func (c *CurrSymbol) UnmarshalXML(d *xml.Decoder, start xml.StartElement) error {
+	var value string
+
+	err := d.DecodeElement(&value, &start)
+	if err != nil {
+		return err
+	}
+
+	value = strings.TrimSpace(value)
+
+	unit, err := currency.ParseISO(value)
+	if err != nil {
+		errors.New("Error parsing CurrSymbol:" + err.Error())
+	}
+	c.Unit = unit
+	return nil
+}
+
+// MarshalXML marshals a CurrSymbol to SGML/XML
+func (c *CurrSymbol) MarshalXML(e *xml.Encoder, start xml.StartElement) error {
+	return e.EncodeElement(c.String(), start)
+}
+
+// Equal returns true if the two Currencies are the same
+func (c CurrSymbol) Equal(o CurrSymbol) bool {
+	return c.String() == o.String()
+}
+
+// Valid returns true, nil if the CurrSymbol is valid.
+func (c CurrSymbol) Valid() (bool, error) {
+	if c.String() == "XXX" {
+		return false, fmt.Errorf("Invalid CurrSymbol: %s", c.Unit)
+	}
+	return true, nil
+}
+
+func NewCurrSymbol(s string) (*CurrSymbol, error) {
+	unit, err := currency.ParseISO(s)
+	if err != nil {
+		return nil, errors.New("Error parsing string to create new CurrSymbol:" + err.Error())
+	}
+	return &CurrSymbol{unit}, nil
+}
diff --git a/types_test.go b/types_test.go
index d07803e..0497223 100644
--- a/types_test.go
+++ b/types_test.go
@@ -373,3 +373,71 @@ func TestRandomUID(t *testing.T) {
 		t.Fatalf("UID generated with RandomUID() doesn't match recommended format: %s\n", err)
 	}
 }
+
+func TestMarshalCurrSymbol(t *testing.T) {
+	c, _ := ofxgo.NewCurrSymbol("USD")
+	marshalHelper(t, "USD", &c)
+}
+
+func TestUnmarshalCurrSymbol(t *testing.T) {
+	var overwritten ofxgo.CurrSymbol
+	c, _ := ofxgo.NewCurrSymbol("USD")
+	unmarshalHelper(t, "USD", c, &overwritten)
+	// Make sure stray newlines are handled properly
+	c, _ = ofxgo.NewCurrSymbol("EUR")
+	unmarshalHelper(t, "EUR\n", c, &overwritten)
+	unmarshalHelper(t, "EUR\n\t", c, &overwritten)
+}
+
+func TestCurrSymbolEqual(t *testing.T) {
+	usd1, _ := ofxgo.NewCurrSymbol("USD")
+	usd2, _ := ofxgo.NewCurrSymbol("USD")
+	if !usd1.Equal(*usd2) {
+		t.Fatalf("Two \"USD\" CurrSymbols returned !Equal()\n")
+	}
+	xxx, _ := ofxgo.NewCurrSymbol("XXX")
+	if usd1.Equal(*xxx) {
+		t.Fatalf("\"USD\" and \"XXX\" CurrSymbols returned Equal()\n")
+	}
+}
+
+func TestCurrSymbolValid(t *testing.T) {
+	var initial ofxgo.CurrSymbol
+	ok, err := initial.Valid()
+	if ok || err == nil {
+		t.Fatalf("CurrSymbol unexpectedly returned Valid() for initial value\n")
+	}
+
+	ars, _ := ofxgo.NewCurrSymbol("ARS")
+	ok, err = ars.Valid()
+	if !ok || err != nil {
+		t.Fatalf("CurrSymbol unexpectedly returned !Valid() for \"ARS\": %s\n", err.Error())
+	}
+
+	xxx, _ := ofxgo.NewCurrSymbol("XXX")
+	ok, err = xxx.Valid()
+	if ok || err == nil {
+		t.Fatalf("CurrSymbol unexpectedly returned Valid() for \"XXX\"\n")
+	}
+}
+
+func TestNewCurrSymbol(t *testing.T) {
+	curr, err := ofxgo.NewCurrSymbol("GBP")
+	if err != nil {
+		t.Fatalf("Unexpected error calling NewCurrSymbol: %s\n", err)
+	}
+	if curr.String() != "GBP" {
+		t.Fatalf("Created CurrSymbol doesn't print \"GBP\" as string representation\n")
+	}
+	curr, err = ofxgo.NewCurrSymbol("AFN")
+	if err != nil {
+		t.Fatalf("Unexpected error calling NewCurrSymbol: %s\n", err)
+	}
+	if curr.String() != "AFN" {
+		t.Fatalf("Created CurrSymbol doesn't print \"AFN\" as string representation\n")
+	}
+	curr, err = ofxgo.NewCurrSymbol("BLAH")
+	if err == nil {
+		t.Fatalf("NewCurrSymbol didn't error on invalid currency identifier\n")
+	}
+}