Rework the Destination filesystem to make --renderStaticToDisk work

See #9626

config/configProvider.go

@@ -45,13 +45,23 @@ func GetStringSlicePreserveString(cfg Provider, key string) []string {
 }
 
 // SetBaseTestDefaults provides some common config defaults used in tests.
-func SetBaseTestDefaults(cfg Provider) {
-	cfg.Set("resourceDir", "resources")
-	cfg.Set("contentDir", "content")
-	cfg.Set("dataDir", "data")
-	cfg.Set("i18nDir", "i18n")
-	cfg.Set("layoutDir", "layouts")
-	cfg.Set("assetDir", "assets")
-	cfg.Set("archetypeDir", "archetypes")
-	cfg.Set("publishDir", "public")
+func SetBaseTestDefaults(cfg Provider) Provider {
+	setIfNotSet(cfg, "baseURL", "https://example.org")
+	setIfNotSet(cfg, "resourceDir", "resources")
+	setIfNotSet(cfg, "contentDir", "content")
+	setIfNotSet(cfg, "dataDir", "data")
+	setIfNotSet(cfg, "i18nDir", "i18n")
+	setIfNotSet(cfg, "layoutDir", "layouts")
+	setIfNotSet(cfg, "assetDir", "assets")
+	setIfNotSet(cfg, "archetypeDir", "archetypes")
+	setIfNotSet(cfg, "publishDir", "public")
+	setIfNotSet(cfg, "workingDir", "")
+	setIfNotSet(cfg, "defaultContentLanguage", "en")
+	return cfg
+}
+
+func setIfNotSet(cfg Provider, key string, value any) {
+	if !cfg.IsSet(key) {
+		cfg.Set(key, value)
+	}
 }

config/defaultConfigProvider.go

@@ -75,6 +75,11 @@ func NewFrom(params maps.Params) Provider {
 	}
 }
 
+// NewWithTestDefaults is used in tests only.
+func NewWithTestDefaults() Provider {
+	return SetBaseTestDefaults(New())
+}
+
 // defaultConfigProvider is a Provider backed by a map where all keys are lower case.
 // All methods are thread safe.
 type defaultConfigProvider struct {

config/services/servicesConfig_test.go

@@ -54,7 +54,7 @@ disableInlineCSS = true
 func TestUseSettingsFromRootIfSet(t *testing.T) {
 	c := qt.New(t)
 
-	cfg := config.New()
+	cfg := config.NewWithTestDefaults()
 	cfg.Set("disqusShortname", "root_short")
 	cfg.Set("googleAnalytics", "ga_root")