add base64 encoding capabilities

epp.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"encoding/base64"
 	"flag"
 	"fmt"
 	"io/ioutil"
@@ -31,6 +32,8 @@ func main() {
 		os.Exit(1)
 	}
 
+	pongo2.RegisterFilter("b64enc", filterBase64Encode)
+
 	fileContents, err := readInput(flag.Arg(0))
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "IO error: %s\n", err)
@@ -85,3 +88,7 @@ func environToContext() pongo2.Context {
 
 	return ctx
 }
+
+func filterBase64Encode(in *pongo2.Value, param *pongo2.Value) (*pongo2.Value, *pongo2.Error) {
+	return pongo2.AsValue(base64.StdEncoding.EncodeToString([]byte(in.String()))), nil
+}

epp_test.go

@@ -4,6 +4,8 @@ import (
 	"fmt"
 	"os"
 	"testing"
+
+	"github.com/flosch/pongo2"
 )
 
 func init() {
@@ -49,3 +51,17 @@ I should!
 		t.Errorf("bad expansion: expected '%s', got '%s'", expected, res)
 	}
 }
+
+func TestFilterBase64Encode(t *testing.T) {
+	actualResult, err := filterBase64Encode(pongo2.AsValue("Hello"), pongo2.AsValue(""))
+
+	if err != nil {
+		t.Errorf("unexpected error '%s'", err)
+	}
+
+	expectedResult := "SGVsbG8="
+
+	if actualResult.String() != expectedResult {
+		t.Errorf("Expected %s but got %s", expectedResult, actualResult)
+	}
+}