From c3ce23c7b43913a90e7516141494b562a7b960d7 Mon Sep 17 00:00:00 2001
From: Paul Hinze <phinze@phinze.com>
Date: Mon, 4 May 2015 15:43:23 -0500
Subject: [PATCH] core: failing test for a bad module cycle

passing output of one module into input of the following module results
in a cycle
---
 terraform/context_test.go                     | 20 +++++++++++++++++++
 .../validate-module-deps-cycle/a/main.tf      |  5 +++++
 .../validate-module-deps-cycle/b/main.tf      |  4 ++++
 .../validate-module-deps-cycle/main.tf        |  8 ++++++++
 4 files changed, 37 insertions(+)
 create mode 100644 terraform/test-fixtures/validate-module-deps-cycle/a/main.tf
 create mode 100644 terraform/test-fixtures/validate-module-deps-cycle/b/main.tf
 create mode 100644 terraform/test-fixtures/validate-module-deps-cycle/main.tf

diff --git a/terraform/context_test.go b/terraform/context_test.go
index 907f21c4b..2988fca6f 100644
--- a/terraform/context_test.go
+++ b/terraform/context_test.go
@@ -2443,6 +2443,26 @@ func TestContext2Validate_moduleBadResource(t *testing.T) {
 	}
 }
 
+func TestContext2Validate_moduleDepsShouldNotCycle(t *testing.T) {
+	m := testModule(t, "validate-module-deps-cycle")
+	p := testProvider("aws")
+	ctx := testContext2(t, &ContextOpts{
+		Module: m,
+		Providers: map[string]ResourceProviderFactory{
+			"aws": testProviderFuncFixed(p),
+		},
+	})
+
+	w, e := ctx.Validate()
+
+	if len(w) > 0 {
+		t.Fatalf("expected no warnings, got: %s", w)
+	}
+	if len(e) > 0 {
+		t.Fatalf("expected no errors, got: %s", e)
+	}
+}
+
 func TestContext2Validate_moduleProviderInherit(t *testing.T) {
 	m := testModule(t, "validate-module-pc-inherit")
 	p := testProvider("aws")
diff --git a/terraform/test-fixtures/validate-module-deps-cycle/a/main.tf b/terraform/test-fixtures/validate-module-deps-cycle/a/main.tf
new file mode 100644
index 000000000..3d3b01634
--- /dev/null
+++ b/terraform/test-fixtures/validate-module-deps-cycle/a/main.tf
@@ -0,0 +1,5 @@
+resource "aws_instance" "a" { }
+
+output "output" {
+  value = "${aws_instance.a.id}"
+}
diff --git a/terraform/test-fixtures/validate-module-deps-cycle/b/main.tf b/terraform/test-fixtures/validate-module-deps-cycle/b/main.tf
new file mode 100644
index 000000000..d43b6c0c0
--- /dev/null
+++ b/terraform/test-fixtures/validate-module-deps-cycle/b/main.tf
@@ -0,0 +1,4 @@
+variable "input" {}
+resource "aws_instance" "b" {
+  name = "${var.input}"
+}
diff --git a/terraform/test-fixtures/validate-module-deps-cycle/main.tf b/terraform/test-fixtures/validate-module-deps-cycle/main.tf
new file mode 100644
index 000000000..11ddb64bf
--- /dev/null
+++ b/terraform/test-fixtures/validate-module-deps-cycle/main.tf
@@ -0,0 +1,8 @@
+module "a" {
+  source = "./a"
+}
+
+module "b" {
+  source = "./b"
+  input = "${module.a.output}"
+}