terraform: test cases around self-referencing variables

This includes cases of multi-counts.

/cc @armon - Looks like this was a non-issue. Terraform already errors
on this.

terraform/context_test.go

@@ -249,6 +249,63 @@ func TestContextValidate_provisionerConfig_good(t *testing.T) {
 	}
 }
 
+func TestContextValidate_selfRef(t *testing.T) {
+	p := testProvider("aws")
+	config := testConfig(t, "validate-self-ref")
+	c := testContext(t, &ContextOpts{
+		Config: config,
+		Providers: map[string]ResourceProviderFactory{
+			"aws": testProviderFuncFixed(p),
+		},
+	})
+
+	w, e := c.Validate()
+	if len(w) > 0 {
+		t.Fatalf("bad: %#v", w)
+	}
+	if len(e) == 0 {
+		t.Fatalf("bad: %#v", e)
+	}
+}
+
+func TestContextValidate_selfRefMulti(t *testing.T) {
+	p := testProvider("aws")
+	config := testConfig(t, "validate-self-ref-multi")
+	c := testContext(t, &ContextOpts{
+		Config: config,
+		Providers: map[string]ResourceProviderFactory{
+			"aws": testProviderFuncFixed(p),
+		},
+	})
+
+	w, e := c.Validate()
+	if len(w) > 0 {
+		t.Fatalf("bad: %#v", w)
+	}
+	if len(e) == 0 {
+		t.Fatalf("bad: %#v", e)
+	}
+}
+
+func TestContextValidate_selfRefMultiAll(t *testing.T) {
+	p := testProvider("aws")
+	config := testConfig(t, "validate-self-ref-multi-all")
+	c := testContext(t, &ContextOpts{
+		Config: config,
+		Providers: map[string]ResourceProviderFactory{
+			"aws": testProviderFuncFixed(p),
+		},
+	})
+
+	w, e := c.Validate()
+	if len(w) > 0 {
+		t.Fatalf("bad: %#v", w)
+	}
+	if len(e) == 0 {
+		t.Fatalf("bad: %#v", e)
+	}
+}
+
 func TestContextApply(t *testing.T) {
 	c := testConfig(t, "apply-good")
 	p := testProvider("aws")

terraform/test-fixtures/validate-self-ref-multi-all/main.tf

@@ -0,0 +1,4 @@
+resource "aws_instance" "web" {
+    foo = "${aws_instance.web.*.foo}"
+    count = 4
+}

terraform/test-fixtures/validate-self-ref-multi/main.tf

@@ -0,0 +1,4 @@
+resource "aws_instance" "web" {
+    foo = "${aws_instance.web.0.foo}"
+    count = 4
+}

terraform/test-fixtures/validate-self-ref/main.tf

@@ -0,0 +1,3 @@
+resource "aws_instance" "web" {
+    foo = "${aws_instance.web.foo}"
+}