config: Outputs is now a slice

config/config.go

@@ -16,7 +16,7 @@ type Config struct {
 	ProviderConfigs map[string]*ProviderConfig
 	Resources       []*Resource
 	Variables       []*Variable
-	Outputs         map[string]*Output
+	Outputs         []*Output
 
 	// The fields below can be filled in by loaders for validation
 	// purposes.

config/loader_libucl.go

@@ -183,7 +183,7 @@ func loadFileLibucl(root string) (configurable, []string, error) {
 
 // LoadOutputsLibucl recurses into the given libucl object and turns
 // it into a mapping of outputs.
-func loadOutputsLibucl(o *libucl.Object) (map[string]*Output, error) {
+func loadOutputsLibucl(o *libucl.Object) ([]*Output, error) {
 	objects := make(map[string]*libucl.Object)
 
 	// Iterate over all the "output" blocks and get the keys along with
@@ -201,8 +201,13 @@ func loadOutputsLibucl(o *libucl.Object) (map[string]*Output, error) {
 	}
 	iter.Close()
 
+	// If we have none, just return nil
+	if len(objects) == 0 {
+		return nil, nil
+	}
+
 	// Go through each object and turn it into an actual result.
-	result := make(map[string]*Output)
+	result := make([]*Output, 0, len(objects))
 	for n, o := range objects {
 		var config map[string]interface{}
 
@@ -218,10 +223,10 @@ func loadOutputsLibucl(o *libucl.Object) (map[string]*Output, error) {
 				err)
 		}
 
-		result[n] = &Output{
+		result = append(result, &Output{
 			Name:      n,
 			RawConfig: rawConfig,
-		}
+		})
 	}
 
 	return result, nil

config/loader_test.go

@@ -156,16 +156,18 @@ func TestLoadDir_noConfigs(t *testing.T) {
 	}
 }
 
-func outputsStr(os map[string]*Output) string {
+func outputsStr(os []*Output) string {
 	ns := make([]string, 0, len(os))
-	for n, _ := range os {
-		ns = append(ns, n)
+	m := make(map[string]*Output)
+	for _, o := range os {
+		ns = append(ns, o.Name)
+		m[o.Name] = o
 	}
 	sort.Strings(ns)
 
 	result := ""
 	for _, n := range ns {
-		o := os[n]
+		o := m[n]
 
 		result += fmt.Sprintf("%s\n", n)
 

config/merge.go

@@ -52,12 +52,18 @@ func Merge(c1, c2 *Config) (*Config, error) {
 
 	// Merge outputs: If they collide, just take the latest one for now. In
 	// the future, we might provide smarter merge functionality.
-	c.Outputs = make(map[string]*Output)
-	for k, v := range c1.Outputs {
-		c.Outputs[k] = v
+	if len(c1.Outputs) > 0 || len(c2.Outputs) > 0 {
+		c.Outputs = make([]*Output, 0, len(c1.Outputs)+len(c2.Outputs))
+		m := make(map[string]*Output)
+		for _, v := range c1.Outputs {
+			m[v.Name] = v
+		}
+		for _, v := range c2.Outputs {
+			m[v.Name] = v
+		}
+		for _, v := range m {
+			c.Outputs = append(c.Outputs, v)
 		}
-	for k, v := range c2.Outputs {
-		c.Outputs[k] = v
 	}
 
 	// Merge provider configs: If they collide, we just take the latest one