Fix panic in Invoke

uber-go · May 27, 2017 · 9c4ee57 · 9c4ee57
1 parent 13204cd
commit 9c4ee57
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Showing 2 changed files with 8 additions and 0 deletions.
diff --git a/dig.go b/dig.go
@@ -88,6 +88,9 @@ func (c *Container) Provide(constructor interface{}) error {
 // immediately.
 func (c *Container) Invoke(function interface{}) error {
 	ftype := reflect.TypeOf(function)
+	if ftype == nil {
+		return errors.New("can't invoke an untyped nil")
+	}
 	if ftype.Kind() != reflect.Func {
 		return fmt.Errorf("can't invoke non-function %v (type %v)", function, ftype)
 	}

diff --git a/dig_test.go b/dig_test.go
@@ -337,6 +337,11 @@ func TestInvokesUseCachedObjects(t *testing.T) {
 func TestInvokeFailures(t *testing.T) {
 	t.Parallel()
 
+	t.Run("untyped nil", func(t *testing.T) {
+		c := New()
+		assert.Error(t, c.Invoke(nil))
+	})
+
 	t.Run("unmet dependency", func(t *testing.T) {
 		c := New()
 		assert.Error(t, c.Invoke(func(*bytes.Buffer) {}))