tiltfile: fix a bug in helm(namespace=) semantics. Fixes #3701 (#3702)

internal/k8s/client.go

@@ -42,6 +42,7 @@ type NodeID string
 type ServiceName string
 type KubeContext string
 
+// NOTE(nick): This isn't right. DefaultNamespace is a function of your kubectl context.
 const DefaultNamespace = Namespace("default")
 
 var ForbiddenFieldsRe = regexp.MustCompile(`updates to .* are forbidden`)

internal/k8s/entity.go

@@ -221,6 +221,14 @@ func (e K8sEntity) Namespace() Namespace {
 	return Namespace(n)
 }
 
+func (e K8sEntity) NamespaceOrDefault(defaultVal string) string {
+	n := e.meta().GetNamespace()
+	if n == "" {
+		return defaultVal
+	}
+	return n
+}
+
 func (e K8sEntity) UID() types.UID {
 	return e.meta().GetUID()
 }

internal/tiltfile/files.go

@@ -247,7 +247,7 @@ func (s *tiltfileState) helm(thread *starlark.Thread, fn *starlark.Builtin, args
 		}
 
 		for i, e := range parsed {
-			parsed[i] = e.WithNamespace(namespace)
+			parsed[i] = e.WithNamespace(e.NamespaceOrDefault(namespace))
 		}
 
 		yaml, err = k8s.SerializeSpecYAML(parsed)

internal/tiltfile/helm_test.go

@@ -9,6 +9,36 @@ import (
 	"github.com/tilt-dev/tilt/internal/tiltfile/testdata"
 )
 
+func TestHelmNamespace(t *testing.T) {
+	f := newFixture(t)
+	defer f.TearDown()
+
+	f.setupHelm()
+	f.file("helm/templates/public-config.yaml", `apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: public-config
+  namespace: kube-public
+data:
+  noData: "true"
+`)
+
+	f.file("Tiltfile", `
+yml = helm('./helm', name='rose-quartz', namespace='garnet')
+k8s_yaml(yml)
+`)
+
+	f.load()
+
+	m := f.assertNextManifestUnresourced(
+		"public-config",
+		"rose-quartz-helloworld-chart")
+	yaml := m.K8sTarget().YAML
+
+	assert.Contains(t, yaml, "name: rose-quartz-helloworld-chart\n  namespace: garnet")
+	assert.Contains(t, yaml, "name: public-config\n  namespace: kube-public")
+}
+
 func TestHelmSetArgs(t *testing.T) {
 	f := newFixture(t)
 	defer f.TearDown()