add a test for the new behavior, include import in go.mod

Signed-off-by: Andrew Lavery <laverya@umich.edu>

go.mod

@@ -36,6 +36,7 @@ require (
 	github.com/stretchr/testify v1.6.1
 	github.com/xeipuuv/gojsonschema v1.2.0
 	golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9
+	gopkg.in/yaml.v2 v2.3.0 // indirect
 	k8s.io/api v0.19.2
 	k8s.io/apiextensions-apiserver v0.19.2
 	k8s.io/apimachinery v0.19.2

pkg/engine/funcs_test.go

@@ -94,6 +94,10 @@ func TestFuncs(t *testing.T) {
 		tpl:    `{{ fromYamlArray . }}`,
 		expect: `[error unmarshaling JSON: while decoding JSON: json: cannot unmarshal object into Go value of type []interface {}]`,
 		vars:   `hello: world`,
+	}, {
+		tpl:    `{{ toYaml . }}`,
+		expect: `foo: this string needs to be more than 80 characters in order to trigger the wrapping behavior in gopkg.in/yaml.v2 <= 2.2.8`,
+		vars:   map[string]interface{}{"foo": "this string needs to be more than 80 characters in order to trigger the wrapping behavior in gopkg.in/yaml.v2 <= 2.2.8"},
 	}, {
 		// This should never result in a network lookup. Regression for #7955
 		tpl:    `{{ lookup "v1" "Namespace" "" "unlikelynamespace99999999" }}`,