config: merge resources

config/config_tree.go

@@ -1,5 +1,9 @@
 package config
 
+import (
+	"fmt"
+)
+
 // configTree represents a tree of configurations where the root is the
 // first file and its children are the configurations it has imported.
 type configTree struct {
@@ -62,7 +66,22 @@ func mergeConfig(c1, c2 *Config) (*Config, error) {
 		c.Variables[k] = v2
 	}
 
-	// TODO: merge resources
+	// Merge resources: If they collide, we just take the latest one
+	// for now. In the future, we might provide smarter merge functionality.
+	resources := make(map[string]Resource)
+	for _, r := range c1.Resources {
+		id := fmt.Sprintf("%s[%s]", r.Type, r.Name)
+		resources[id] = r
+	}
+	for _, r := range c2.Resources {
+		id := fmt.Sprintf("%s[%s]", r.Type, r.Name)
+		resources[id] = r
+	}
+
+	c.Resources = make([]Resource, 0, len(resources))
+	for _, r := range resources {
+		c.Resources = append(c.Resources, r)
+	}
 
 	return c, nil
 }

config/loader_test.go

@@ -50,12 +50,10 @@ func TestLoadBasic_import(t *testing.T) {
 		t.Fatalf("bad:\n%s", actual)
 	}
 
-	/*
 	actual = resourcesStr(c.Resources)
-	if actual != strings.TrimSpace(basicResourcesStr) {
+	if actual != strings.TrimSpace(importResourcesStr) {
 		t.Fatalf("bad:\n%s", actual)
 	}
-	*/
 }
 
 // This helper turns a resources field into a deterministic
@@ -111,6 +109,11 @@ foo
   bar
 `
 
+const importResourcesStr = `
+aws_security_group[db]
+aws_security_group[web]
+`
+
 const importVariablesStr = `
 bar
   <>

config/test-fixtures/import.tf

@@ -4,3 +4,5 @@ variable "foo" {
     default = "bar";
     description = "bar";
 }
+
+resource "aws_security_group" "web" {}

config/test-fixtures/import/one.tf

@@ -1 +1,3 @@
 variable "bar" {}
+
+resource "aws_security_group" "db" {}