Make the config loading testable

This is needed to verify  #2309, but it closes a big hole in Hugo's automated tests.

The loading of the config is now moved to `hugolib` and the same default settings are now used
in production and tests.

As Viper now uses Afero as its filesystem, we now can write fairly complete integration tests with ease.

See #2309

3 files changed, 146 insertions, 12 deletions

diff --git a/hugolib/config.go b/hugolib/config.go
new file mode 100644
index 000000000..285e3567a
--- /dev/null
+++ b/hugolib/config.go
@@ -0,0 +1,107 @@
+// Copyright 2016-present The Hugo Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package hugolib
+
+import (
+	"fmt"
+
+	"github.com/spf13/hugo/helpers"
+	"github.com/spf13/viper"
+)
+
+// LoadGlobalConfig loads Hugo configuration into the global Viper.
+func LoadGlobalConfig(relativeSourcePath, configFilename string) error {
+
+	if relativeSourcePath == "" {
+		relativeSourcePath = "."
+	}
+
+	viper.AutomaticEnv()
+	viper.SetEnvPrefix("hugo")
+	viper.SetConfigFile(configFilename)
+	// See https://github.com/spf13/viper/issues/73#issuecomment-126970794
+	if relativeSourcePath == "" {
+		viper.AddConfigPath(".")
+	} else {
+		viper.AddConfigPath(relativeSourcePath)
+	}
+	err := viper.ReadInConfig()
+	if err != nil {
+		if _, ok := err.(viper.ConfigParseError); ok {
+			return err
+		}
+		return fmt.Errorf("Unable to locate Config file. Perhaps you need to create a new site.\n       Run `hugo help new` for details. (%s)\n", err)
+	}
+
+	viper.RegisterAlias("indexes", "taxonomies")
+
+	loadDefaultSettings()
+
+	return nil
+}
+
+func loadDefaultSettings() {
+	viper.SetDefault("cleanDestinationDir", false)
+	viper.SetDefault("Watch", false)
+	viper.SetDefault("MetaDataFormat", "toml")
+	viper.SetDefault("Disable404", false)
+	viper.SetDefault("DisableRSS", false)
+	viper.SetDefault("DisableSitemap", false)
+	viper.SetDefault("DisableRobotsTXT", false)
+	viper.SetDefault("ContentDir", "content")
+	viper.SetDefault("LayoutDir", "layouts")
+	viper.SetDefault("StaticDir", "static")
+	viper.SetDefault("ArchetypeDir", "archetypes")
+	viper.SetDefault("PublishDir", "public")
+	viper.SetDefault("DataDir", "data")
+	viper.SetDefault("I18nDir", "i18n")
+	viper.SetDefault("ThemesDir", "themes")
+	viper.SetDefault("DefaultLayout", "post")
+	viper.SetDefault("BuildDrafts", false)
+	viper.SetDefault("BuildFuture", false)
+	viper.SetDefault("BuildExpired", false)
+	viper.SetDefault("UglyURLs", false)
+	viper.SetDefault("Verbose", false)
+	viper.SetDefault("IgnoreCache", false)
+	viper.SetDefault("CanonifyURLs", false)
+	viper.SetDefault("RelativeURLs", false)
+	viper.SetDefault("RemovePathAccents", false)
+	viper.SetDefault("Taxonomies", map[string]string{"tag": "tags", "category": "categories"})
+	viper.SetDefault("Permalinks", make(PermalinkOverrides, 0))
+	viper.SetDefault("Sitemap", Sitemap{Priority: -1, Filename: "sitemap.xml"})
+	viper.SetDefault("DefaultExtension", "html")
+	viper.SetDefault("PygmentsStyle", "monokai")
+	viper.SetDefault("PygmentsUseClasses", false)
+	viper.SetDefault("PygmentsCodeFences", false)
+	viper.SetDefault("PygmentsOptions", "")
+	viper.SetDefault("DisableLiveReload", false)
+	viper.SetDefault("PluralizeListTitles", true)
+	viper.SetDefault("PreserveTaxonomyNames", false)
+	viper.SetDefault("ForceSyncStatic", false)
+	viper.SetDefault("FootnoteAnchorPrefix", "")
+	viper.SetDefault("FootnoteReturnLinkContents", "")
+	viper.SetDefault("NewContentEditor", "")
+	viper.SetDefault("Paginate", 10)
+	viper.SetDefault("PaginatePath", "page")
+	viper.SetDefault("Blackfriday", helpers.NewBlackfriday())
+	viper.SetDefault("RSSUri", "index.xml")
+	viper.SetDefault("SectionPagesMenu", "")
+	viper.SetDefault("DisablePathToLower", false)
+	viper.SetDefault("HasCJKLanguage", false)
+	viper.SetDefault("EnableEmoji", false)
+	viper.SetDefault("PygmentsCodeFencesGuessSyntax", false)
+	viper.SetDefault("UseModTimeAsFallback", false)
+	viper.SetDefault("Multilingual", false)
+	viper.SetDefault("DefaultContentLanguage", "en")
+}
diff --git a/hugolib/config_test.go b/hugolib/config_test.go
new file mode 100644
index 000000000..db0cb7117
--- /dev/null
+++ b/hugolib/config_test.go
@@ -0,0 +1,37 @@
+// Copyright 2016-present The Hugo Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package hugolib
+
+import (
+	"testing"
+
+	"github.com/spf13/viper"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestLoadGlobalConfig(t *testing.T) {
+	// Add a random config variable for testing.
+	// side = page in Norwegian.
+	configContent := `
+	PaginatePath = "side"
+	`
+
+	writeSource(t, "config.toml", configContent)
+
+	require.NoError(t, LoadGlobalConfig("", "config.toml"))
+	assert.Equal(t, "side", viper.GetString("PaginatePath"))
+	// default
+	assert.Equal(t, "layouts", viper.GetString("LayoutDir"))
+}
diff --git a/hugolib/hugo_sites_test.go b/hugolib/hugo_sites_test.go
index 185c241a5..8e5b6ae16 100644
--- a/hugolib/hugo_sites_test.go
+++ b/hugolib/hugo_sites_test.go
@@ -29,18 +29,8 @@ func init() {
 func testCommonResetState() {
 	hugofs.InitMemFs()
 	viper.Reset()
-	viper.Set("ContentDir", "content")
-	viper.Set("DataDir", "data")
-	viper.Set("I18nDir", "i18n")
-	viper.Set("themesDir", "themes")
-	viper.Set("LayoutDir", "layouts")
-	viper.Set("PublishDir", "public")
-	viper.Set("RSSUri", "rss")
-
-	viper.Set("Taxonomies", map[string]interface{}{
-		"tag":      "tags",
-		"category": "categories",
-	})
+	viper.SetFs(hugofs.Source())
+	loadDefaultSettings()
 
 	if err := hugofs.Source().Mkdir("content", 0755); err != nil {
 		panic("Content folder creation failed.")