providers/heroku: add failing test for var removal

builtin/providers/heroku/resource_heroku_app.go

@@ -120,11 +120,22 @@ func resource_heroku_app_update(
 		rs.ID = renamedApp.Name
 	}
 
-	if attr, ok := d.Attributes["config_vars.#"]; ok && attr.New == "1" {
+	attr, ok := s.Attributes["config_vars.#"]
+
+	// If the config var block was removed, nuke all config vars
+	if ok && attr == "1" {
 		vs := flatmap.Expand(
 			rs.Attributes, "config_vars").([]interface{})
 
 		err := update_config_vars(rs.ID, vs, client)
+		if err != nil {
+			return rs, err
+		}
+	} else if ok && attr == "0" {
+		log.Println("[INFO] Config vars removed, removing all vars")
+
+		err := update_config_vars(rs.ID, make([]interface{}, 0), client)
+
 		if err != nil {
 			return rs, err
 		}
@@ -265,6 +276,8 @@ func update_config_vars(id string, vs []interface{}, client *heroku.Client) erro
 		vars[k] = &val
 	}
 
+	log.Printf("[INFO] Updating config vars: *%#v", vars)
+
 	_, err := client.ConfigVarUpdate(id, vars)
 
 	if err != nil {

builtin/providers/heroku/resource_heroku_app_test.go

@@ -68,6 +68,40 @@ func TestAccHerokuApp_NameChange(t *testing.T) {
 	})
 }
 
+func TestAccHerokuApp_NukeVars(t *testing.T) {
+	var app heroku.App
+
+	resource.Test(t, resource.TestCase{
+		PreCheck:     func() { testAccPreCheck(t) },
+		Providers:    testAccProviders,
+		CheckDestroy: testAccCheckHerokuAppDestroy,
+		Steps: []resource.TestStep{
+			resource.TestStep{
+				Config: testAccCheckHerokuAppConfig_basic,
+				Check: resource.ComposeTestCheckFunc(
+					testAccCheckHerokuAppExists("heroku_app.foobar", &app),
+					testAccCheckHerokuAppAttributes(&app),
+					resource.TestCheckResourceAttr(
+						"heroku_app.foobar", "name", "terraform-test-app"),
+					resource.TestCheckResourceAttr(
+						"heroku_app.foobar", "config_vars.0.FOO", "bar"),
+				),
+			},
+			resource.TestStep{
+				Config: testAccCheckHerokuAppConfig_no_vars,
+				Check: resource.ComposeTestCheckFunc(
+					testAccCheckHerokuAppExists("heroku_app.foobar", &app),
+					testAccCheckHerokuAppAttributesNoVars(&app),
+					resource.TestCheckResourceAttr(
+						"heroku_app.foobar", "name", "terraform-test-app"),
+					resource.TestCheckResourceAttr(
+						"heroku_app.foobar", "config_vars.0.FOO", ""),
+				),
+			},
+		},
+	})
+}
+
 func testAccCheckHerokuAppDestroy(s *terraform.State) error {
 	client := testAccProvider.client
 
@@ -142,10 +176,31 @@ func testAccCheckHerokuAppAttributesUpdated(app *heroku.App) resource.TestCheckF
 	}
 }
 
+func testAccCheckHerokuAppAttributesNoVars(app *heroku.App) resource.TestCheckFunc {
+	return func(s *terraform.State) error {
+		client := testAccProvider.client
+
+		if app.Name != "terraform-test-app" {
+			return fmt.Errorf("Bad name: %s", app.Name)
+		}
+
+		vars, err := client.ConfigVarInfo(app.Name)
+		if err != nil {
+			return err
+		}
+
+		if len(vars) != 0 {
+			return fmt.Errorf("vars exist: %v", vars)
+		}
+
+		return nil
+	}
+}
+
 func testAccCheckHerokuAppExists(n string, app *heroku.App) resource.TestCheckFunc {
 	return func(s *terraform.State) error {
 		rs, ok := s.Resources[n]
-		fmt.Printf("resources %#v", s.Resources)
+
 		if !ok {
 			return fmt.Errorf("Not found: %s", n)
 		}
@@ -176,7 +231,7 @@ const testAccCheckHerokuAppConfig_basic = `
 resource "heroku_app" "foobar" {
     name = "terraform-test-app"
 
-    config_vars = {
+    config_vars {
     	FOO = bar
     }
 }`
@@ -185,8 +240,13 @@ const testAccCheckHerokuAppConfig_updated = `
 resource "heroku_app" "foobar" {
     name = "terraform-test-renamed"
 
-    config_vars = {
+    config_vars {
     	FOO = bing
     	BAZ = bar
     }
 }`
+
+const testAccCheckHerokuAppConfig_no_vars = `
+resource "heroku_app" "foobar" {
+    name = "terraform-test-app"
+}`