From 20da842bcfb1b0a903d76536795918f1dfd4126f Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <mitchell.hashimoto@gmail.com>
Date: Tue, 22 Jul 2014 17:16:48 -0700
Subject: [PATCH] config: validate dependsOn

---
 config/config.go                                     | 11 +++++++++++
 config/config_test.go                                |  7 +++++++
 config/test-fixtures/validate-bad-depends-on/main.tf |  3 +++
 config/test-fixtures/validate-good/main.tf           |  2 ++
 4 files changed, 23 insertions(+)
 create mode 100644 config/test-fixtures/validate-bad-depends-on/main.tf

diff --git a/config/config.go b/config/config.go
index f2c8b41b5..012fcee6f 100644
--- a/config/config.go
+++ b/config/config.go
@@ -155,6 +155,17 @@ func (c *Config) Validate() error {
 	}
 	dupped = nil
 
+	// Make sure all dependsOn are valid in resources
+	for n, r := range resources {
+		for _, d := range r.DependsOn {
+			if _, ok := resources[d]; !ok {
+				errs = append(errs, fmt.Errorf(
+					"%s: resource depends on non-existent resource '%s'",
+					n, d))
+			}
+		}
+	}
+
 	for source, vs := range vars {
 		for _, v := range vs {
 			rv, ok := v.(*ResourceVariable)
diff --git a/config/config_test.go b/config/config_test.go
index 9b141fa8f..508a281ab 100644
--- a/config/config_test.go
+++ b/config/config_test.go
@@ -16,6 +16,13 @@ func TestConfigValidate(t *testing.T) {
 	}
 }
 
+func TestConfigValidate_badDependsOn(t *testing.T) {
+	c := testConfig(t, "validate-bad-depends-on")
+	if err := c.Validate(); err == nil {
+		t.Fatal("should not be valid")
+	}
+}
+
 func TestConfigValidate_badMultiResource(t *testing.T) {
 	c := testConfig(t, "validate-bad-multi-resource")
 	if err := c.Validate(); err == nil {
diff --git a/config/test-fixtures/validate-bad-depends-on/main.tf b/config/test-fixtures/validate-bad-depends-on/main.tf
new file mode 100644
index 000000000..60ca18c7e
--- /dev/null
+++ b/config/test-fixtures/validate-bad-depends-on/main.tf
@@ -0,0 +1,3 @@
+resource "aws_instance" "web" {
+    depends_on = ["aws_instance.db"]
+}
diff --git a/config/test-fixtures/validate-good/main.tf b/config/test-fixtures/validate-good/main.tf
index 965877a10..5a4f87159 100644
--- a/config/test-fixtures/validate-good/main.tf
+++ b/config/test-fixtures/validate-good/main.tf
@@ -32,4 +32,6 @@ resource aws_instance "web" {
         device_index = 0
         description = "Main network interface"
     }
+
+    depends_on = ["aws_security_group.firewall"]
 }