Fix rendering an app without any default settings but some user settings fails

* It fixes the settings.FromFlatten function, which was returning recursive Settings, instead of map[string]interface{}. The render worked if the default settings were overridden, which are already with the good type (map[string]interface{}).

Signed-off-by: Silvin Lubecki <silvin.lubecki@docker.com>

Author: silvin-lubecki

render/render_test.go

@@ -106,12 +106,9 @@ back:
   image: wrong
 `)
 	app := &types.App{Path: "my-app"}
-	err := types.Metadata(metadata)(app)
-	assert.NilError(t, err)
-	err = types.WithComposes(composeFile)(app)
-	assert.NilError(t, err)
-	err = types.WithSettings(settings)(app)
-	assert.NilError(t, err)
+	assert.NilError(t, types.Metadata(metadata)(app))
+	assert.NilError(t, types.WithComposes(composeFile)(app))
+	assert.NilError(t, types.WithSettings(settings)(app))
 	userSettings := map[string]string{
 		"front.image": "nginx",
 		"front.port":  "4242",
@@ -135,6 +132,33 @@ services:
 `)
 }
 
+func TestRenderWithoutDefaultSettings(t *testing.T) {
+	metadata := strings.NewReader(validMeta)
+	composeFile := strings.NewReader(`
+version: "3.6"
+services:
+  front:
+    image: ${front.image}
+`)
+	settings := strings.NewReader("")
+	app := &types.App{Path: "my-app"}
+	assert.NilError(t, types.Metadata(metadata)(app))
+	assert.NilError(t, types.WithComposes(composeFile)(app))
+	assert.NilError(t, types.WithSettings(settings)(app))
+	userSettings := map[string]string{
+		"front.image": "nginx",
+	}
+	c, err := Render(app, userSettings)
+	assert.NilError(t, err)
+	s, err := yaml.Marshal(c)
+	assert.NilError(t, err)
+	assert.Equal(t, string(s), `version: "3.6"
+services:
+  front:
+    image: nginx
+`)
+}
+
 func TestValidateBrokenComposeFile(t *testing.T) {
 	metadata := strings.NewReader(validMeta)
 	brokenComposeFile := strings.NewReader(`version: "3.6"

types/settings/settings.go

@@ -100,9 +100,9 @@ func assignKey(m map[string]interface{}, keys []string, value interface{}) error
 		return nil
 	}
 	if v, present := m[key]; !present {
-		m[key] = Settings{}
-	} else if _, isMap := v.(Settings); !isMap {
+		m[key] = map[string]interface{}{}
+	} else if _, isMap := v.(map[string]interface{}); !isMap {
 		return errors.Errorf("key %s already present and not a map (%T)", key, v)
 	}
-	return assignKey(m[key].(Settings), ks, value)
+	return assignKey(m[key].(map[string]interface{}), ks, value)
 }

types/settings/settings_test.go

@@ -47,12 +47,12 @@ func TestFromFlatten(t *testing.T) {
 	assert.NilError(t, err)
 	assert.Check(t, is.DeepEqual(s, Settings{
 		"foo": "bar",
-		"bar": Settings{
+		"bar": map[string]interface{}{
 			"baz":  "banana",
 			"port": 80,
 		},
-		"baz": Settings{
-			"biz": Settings{
+		"baz": map[string]interface{}{
+			"biz": map[string]interface{}{
 				"a": 1,
 				"b": 2,
 			},