Improve language handling in URLs

The current "rendering language" is needed outside of Site. This commit moves the Language type to the helpers package, and then used to get correct correct language configuration in the markdownify template func.
This commit also adds two new template funcs: relLangURL and absLangURL.

See #2309

helpers/url_test.go

@@ -14,11 +14,13 @@
 package helpers
 
 import (
+	"fmt"
 	"strings"
 	"testing"
 
 	"github.com/spf13/viper"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 func TestURLize(t *testing.T) {
@@ -43,62 +45,114 @@ func TestURLize(t *testing.T) {
 }
 
 func TestAbsURL(t *testing.T) {
-	defer viper.Reset()
+	for _, addLanguage := range []bool{true, false} {
+		for _, m := range []bool{true, false} {
+			for _, l := range []string{"en", "fr"} {
+				doTestAbsURL(t, addLanguage, m, l)
+			}
+		}
+	}
+}
+
+func doTestAbsURL(t *testing.T, addLanguage, multilingual bool, lang string) {
+	viper.Reset()
+	viper.Set("Multilingual", multilingual)
+	viper.Set("CurrentContentLanguage", NewLanguage(lang))
 	tests := []struct {
 		input    string
 		baseURL  string
 		expected string
 	}{
-		{"/test/foo", "http://base/", "http://base/test/foo"},
-		{"", "http://base/ace/", "http://base/ace/"},
-		{"/test/2/foo/", "http://base", "http://base/test/2/foo/"},
+		{"/test/foo", "http://base/", "http://base/MULTItest/foo"},
+		{"", "http://base/ace/", "http://base/ace/MULTI"},
+		{"/test/2/foo/", "http://base", "http://base/MULTItest/2/foo/"},
 		{"http://abs", "http://base/", "http://abs"},
 		{"schema://abs", "http://base/", "schema://abs"},
 		{"//schemaless", "http://base/", "//schemaless"},
-		{"test/2/foo/", "http://base/path", "http://base/path/test/2/foo/"},
-		{"/test/2/foo/", "http://base/path", "http://base/test/2/foo/"},
-		{"http//foo", "http://base/path", "http://base/path/http/foo"},
+		{"test/2/foo/", "http://base/path", "http://base/path/MULTItest/2/foo/"},
+		{"/test/2/foo/", "http://base/path", "http://base/MULTItest/2/foo/"},
+		{"http//foo", "http://base/path", "http://base/path/MULTIhttp/foo"},
 	}
 
 	for _, test := range tests {
-		viper.Reset()
 		viper.Set("BaseURL", test.baseURL)
-		output := AbsURL(test.input)
-		if output != test.expected {
-			t.Errorf("Expected %#v, got %#v\n", test.expected, output)
+		output := AbsURL(test.input, addLanguage)
+		expected := test.expected
+		if multilingual && addLanguage {
+			expected = strings.Replace(expected, "MULTI", lang+"/", 1)
+		} else {
+			expected = strings.Replace(expected, "MULTI", "", 1)
+		}
+		if output != expected {
+			t.Errorf("Expected %#v, got %#v\n", expected, output)
 		}
 	}
 }
 
+func TestIsAbsURL(t *testing.T) {
+	for i, this := range []struct {
+		a string
+		b bool
+	}{
+		{"http://gohugo.io", true},
+		{"https://gohugo.io", true},
+		{"//gohugo.io", true},
+		{"http//gohugo.io", false},
+		{"/content", false},
+		{"content", false},
+	} {
+		require.True(t, IsAbsURL(this.a) == this.b, fmt.Sprintf("Test %d", i))
+	}
+}
+
 func TestRelURL(t *testing.T) {
-	defer viper.Reset()
-	//defer viper.Set("canonifyURLs", viper.GetBool("canonifyURLs"))
+	for _, addLanguage := range []bool{true, false} {
+		for _, m := range []bool{true, false} {
+			for _, l := range []string{"en", "fr"} {
+				doTestRelURL(t, addLanguage, m, l)
+			}
+		}
+	}
+}
+
+func doTestRelURL(t *testing.T, addLanguage, multilingual bool, lang string) {
+	viper.Reset()
+	viper.Set("Multilingual", multilingual)
+	viper.Set("CurrentContentLanguage", NewLanguage(lang))
+
 	tests := []struct {
 		input    string
 		baseURL  string
 		canonify bool
 		expected string
 	}{
-		{"/test/foo", "http://base/", false, "/test/foo"},
-		{"test.css", "http://base/sub", false, "/sub/test.css"},
-		{"test.css", "http://base/sub", true, "/test.css"},
-		{"/test/", "http://base/", false, "/test/"},
-		{"/test/", "http://base/sub/", false, "/sub/test/"},
-		{"/test/", "http://base/sub/", true, "/test/"},
-		{"", "http://base/ace/", false, "/ace/"},
-		{"", "http://base/ace", false, "/ace"},
+		{"/test/foo", "http://base/", false, "MULTI/test/foo"},
+		{"test.css", "http://base/sub", false, "/subMULTI/test.css"},
+		{"test.css", "http://base/sub", true, "MULTI/test.css"},
+		{"/test/", "http://base/", false, "MULTI/test/"},
+		{"/test/", "http://base/sub/", false, "/subMULTI/test/"},
+		{"/test/", "http://base/sub/", true, "MULTI/test/"},
+		{"", "http://base/ace/", false, "/aceMULTI/"},
+		{"", "http://base/ace", false, "/aceMULTI"},
 		{"http://abs", "http://base/", false, "http://abs"},
 		{"//schemaless", "http://base/", false, "//schemaless"},
 	}
 
 	for i, test := range tests {
-		viper.Reset()
 		viper.Set("BaseURL", test.baseURL)
 		viper.Set("canonifyURLs", test.canonify)
 
-		output := RelURL(test.input)
-		if output != test.expected {
-			t.Errorf("[%d][%t] Expected %#v, got %#v\n", i, test.canonify, test.expected, output)
+		output := RelURL(test.input, addLanguage)
+
+		expected := test.expected
+		if multilingual && addLanguage {
+			expected = strings.Replace(expected, "MULTI", "/"+lang, 1)
+		} else {
+			expected = strings.Replace(expected, "MULTI", "", 1)
+		}
+
+		if output != expected {
+			t.Errorf("[%d][%t] Expected %#v, got %#v\n", i, test.canonify, expected, output)
 		}
 	}
 }