config: validate that count is >= 1

config/config.go

@@ -155,8 +155,14 @@ func (c *Config) Validate() error {
 	}
 	dupped = nil
 
-	// Make sure all dependsOn are valid in resources
+	// Validate resources
 	for n, r := range resources {
+		if r.Count < 1 {
+			errs = append(errs, fmt.Errorf(
+				"%s: count must be greater than or equal to 1",
+				n))
+		}
+
 		for _, d := range r.DependsOn {
 			if _, ok := resources[d]; !ok {
 				errs = append(errs, fmt.Errorf(

config/config_test.go

@@ -30,6 +30,20 @@ func TestConfigValidate_badMultiResource(t *testing.T) {
 	}
 }
 
+func TestConfigValidate_countBelowZero(t *testing.T) {
+	c := testConfig(t, "validate-count-below-zero")
+	if err := c.Validate(); err == nil {
+		t.Fatal("should not be valid")
+	}
+}
+
+func TestConfigValidate_countZero(t *testing.T) {
+	c := testConfig(t, "validate-count-zero")
+	if err := c.Validate(); err == nil {
+		t.Fatal("should not be valid")
+	}
+}
+
 func TestConfigValidate_dupResource(t *testing.T) {
 	c := testConfig(t, "validate-dup-resource")
 	if err := c.Validate(); err == nil {

config/test-fixtures/validate-count-below-zero/main.tf

@@ -0,0 +1,3 @@
+resource "aws_instance" "web" {
+    count = -1
+}

config/test-fixtures/validate-count-zero/main.tf

@@ -0,0 +1,3 @@
+resource "aws_instance" "web" {
+    count = 0
+}