Add multilingual multihost support

Updates gohugoio#4027

hugolib/hugo_sites_build_test.go

@@ -1269,7 +1269,7 @@ lag:
 		t.Fatalf("Failed to create sites: %s", err)
 	}
 
-	if len(sites.Sites) != 4 {
+	if len(sites.Sites) == 0 {
 		t.Fatalf("Got %d sites", len(sites.Sites))
 	}
 

hugolib/hugo_sites_multihost_test.go

@@ -0,0 +1,62 @@
+package hugolib
+
+import (
+	"testing"
+
+	"github.com/spf13/afero"
+	"github.com/stretchr/testify/require"
+)
+
+func TestMultihosts(t *testing.T) {
+	t.Parallel()
+
+	var multiSiteTOMLConfigTemplate = `
+paginate = 1
+disablePathToLower = true
+defaultContentLanguage = "{{ .DefaultContentLanguage }}"
+
+[permalinks]
+other = "/somewhere/else/:filename"
+
+[Taxonomies]
+tag = "tags"
+
+[Languages]
+[Languages.en]
+baseURL = "https://example.com"
+weight = 10
+title = "In English"
+languageName = "English"
+
+[Languages.fr]
+baseURL = "https://example.fr"
+weight = 20
+title = "Le Français"
+languageName = "Français"
+
+[Languages.nn]
+baseURL = "https://example.no"
+weight = 30
+title = "På nynorsk"
+languageName = "Nynorsk"
+
+`
+
+	siteConfig := testSiteConfig{Fs: afero.NewMemMapFs(), DefaultContentLanguage: "fr", DefaultContentLanguageInSubdir: true}
+	sites := createMultiTestSites(t, siteConfig, multiSiteTOMLConfigTemplate)
+	fs := sites.Fs
+	cfg := BuildCfg{Watching: true}
+	th := testHelper{sites.Cfg, fs, t}
+	assert := require.New(t)
+
+	err := sites.Build(cfg)
+	assert.NoError(err)
+
+	th.assertFileContent("public/en/sect/doc1-slug/index.html", "Hello")
+	enSite := sites.Sites[0]
+	enSiteHome := enSite.getPage(KindHome)
+	assert.True(enSiteHome.IsTranslated())
+	assert.Len(enSiteHome.Translations(), 2)
+	assert.Equal("https://example.com/", enSiteHome.Permalink())
+
+}