terraform: tests passing for Config change

config/loader_libucl.go

@@ -48,22 +48,24 @@ func (t *libuclConfigurable) Config() (*Config, error) {
 	// TODO(mitchellh): Make function like loadVariablesLibucl so that
 	// duplicates aren't overriden
 	config := new(Config)
-	config.Variables = make([]*Variable, 0, len(rawConfig.Variable))
-	for k, v := range rawConfig.Variable {
-		defaultSet := false
-		for _, f := range v.Fields {
-			if f == "Default" {
-				defaultSet = true
-				break
+	if len(rawConfig.Variable) > 0 {
+		config.Variables = make([]*Variable, 0, len(rawConfig.Variable))
+		for k, v := range rawConfig.Variable {
+			defaultSet := false
+			for _, f := range v.Fields {
+				if f == "Default" {
+					defaultSet = true
+					break
+				}
 			}
-		}
 
-		config.Variables = append(config.Variables, &Variable{
-			Name:        k,
-			Default:     v.Default,
-			Description: v.Description,
-			defaultSet:  defaultSet,
-		})
+			config.Variables = append(config.Variables, &Variable{
+				Name:        k,
+				Default:     v.Default,
+				Description: v.Description,
+				defaultSet:  defaultSet,
+			})
+		}
 	}
 
 	// Build the provider configs

config/merge.go

@@ -26,26 +26,28 @@ func Merge(c1, c2 *Config) (*Config, error) {
 
 	// Merge variables: Variable merging is quite simple. Set fields in
 	// later set variables override those earlier.
-	c.Variables = make([]*Variable, 0, len(c1.Variables)+len(c2.Variables))
-	varMap := make(map[string]*Variable)
-	for _, v := range c1.Variables {
-		varMap[v.Name] = v
-	}
-	for _, v2 := range c2.Variables {
-		v1, ok := varMap[v2.Name]
-		if ok {
-			if v2.Default == "" {
-				v2.Default = v1.Default
-			}
-			if v2.Description == "" {
-				v2.Description = v1.Description
-			}
+	if len(c1.Variables) > 0 || len(c2.Variables) > 0 {
+		c.Variables = make([]*Variable, 0, len(c1.Variables)+len(c2.Variables))
+		varMap := make(map[string]*Variable)
+		for _, v := range c1.Variables {
+			varMap[v.Name] = v
 		}
+		for _, v2 := range c2.Variables {
+			v1, ok := varMap[v2.Name]
+			if ok {
+				if v2.Default == "" {
+					v2.Default = v1.Default
+				}
+				if v2.Description == "" {
+					v2.Description = v1.Description
+				}
+			}
 
-		varMap[v2.Name] = v2
-	}
-	for _, v := range varMap {
-		c.Variables = append(c.Variables, v)
+			varMap[v2.Name] = v2
+		}
+		for _, v := range varMap {
+			c.Variables = append(c.Variables, v)
+		}
 	}
 
 	// Merge outputs: If they collide, just take the latest one for now. In

terraform/plan_test.go

@@ -53,6 +53,8 @@ func TestReadWritePlan(t *testing.T) {
 		t.Fatalf("err: %s", err)
 	}
 
+	println(reflect.DeepEqual(actual.Config.Variables, plan.Config.Variables))
+
 	if !reflect.DeepEqual(actual, plan) {
 		t.Fatalf("bad: %#v", actual)
 	}

terraform/semantics.go

@@ -13,9 +13,9 @@ func smcUserVariables(c *config.Config, vs map[string]string) []error {
 
 	// Check that all required variables are present
 	required := make(map[string]struct{})
-	for k, v := range c.Variables {
+	for _, v := range c.Variables {
 		if v.Required() {
-			required[k] = struct{}{}
+			required[v.Name] = struct{}{}
 		}
 	}
 	for k, _ := range vs {