From 8c94c76da6499660d79924c0b8d0daa1862d57db Mon Sep 17 00:00:00 2001
From: Romain Beuque <romain.beuque@corp.ovh.com>
Date: Mon, 23 Mar 2020 17:41:52 +0100
Subject: [PATCH] fix: base_output not used if the plugin Output is not a
 map[string]interface{}

Signed-off-by: Romain Beuque <romain.beuque@corp.ovh.com>
---
 engine/engine_test.go                 | 17 +++++++++++++++++
 engine/step/step.go                   |  8 ++++----
 engine/templates_tests/no-output.yaml | 13 +++++++++++++
 3 files changed, 34 insertions(+), 4 deletions(-)
 create mode 100644 engine/templates_tests/no-output.yaml

diff --git a/engine/engine_test.go b/engine/engine_test.go
index df5b2d0b..c70c1caf 100644
--- a/engine/engine_test.go
+++ b/engine/engine_test.go
@@ -646,6 +646,23 @@ func TestEmptyStringInput(t *testing.T) {
 	assert.Equal(t, "", output["foo"])
 }
 
+func TestBaseOutputNoOutput(t *testing.T) {
+	input := map[string]interface{}{}
+	res, err := createResolution("no-output.yaml", input, nil)
+	require.NotNil(t, res)
+	require.Nil(t, err)
+
+	res, err = runResolution(res)
+
+	require.Nilf(t, err, "got error %s", err)
+	require.NotNil(t, res)
+	assert.Equal(t, resolution.StateDone, res.State)
+	assert.Equal(t, step.StateDone, res.Steps["stepOne"].State)
+
+	output := res.Steps["stepOne"].Output.(map[string]interface{})
+	assert.Equal(t, "buzz", output["foobar"])
+}
+
 func TestScriptPlugin(t *testing.T) {
 	argv := "world"
 	res, err := createResolution("execScript.yaml", map[string]interface{}{"argv": argv}, nil)
diff --git a/engine/step/step.go b/engine/step/step.go
index a4ea5a17..19926768 100644
--- a/engine/step/step.go
+++ b/engine/step/step.go
@@ -266,13 +266,13 @@ func Run(st *Step, baseConfig map[string]json.RawMessage, values *values.Values,
 		default:
 			st.Output, st.Metadata, err = runner.Exec(st.Name, baseCfgRaw, config, ctx)
 			if baseOutput != nil {
-				marshaled, err := json.Marshal(st.Output)
-				if err == nil {
-					err = utils.JSONnumberUnmarshal(bytes.NewReader(marshaled), &baseOutput)
+				if st.Output != nil {
+					marshaled, err := json.Marshal(st.Output)
 					if err == nil {
-						st.Output = baseOutput
+						_ = utils.JSONnumberUnmarshal(bytes.NewReader(marshaled), &baseOutput)
 					}
 				}
+				st.Output = baseOutput
 			}
 			st.Payload = st.Output // FIXME deprecate
 			if err != nil {
diff --git a/engine/templates_tests/no-output.yaml b/engine/templates_tests/no-output.yaml
new file mode 100644
index 00000000..51baed3f
--- /dev/null
+++ b/engine/templates_tests/no-output.yaml
@@ -0,0 +1,13 @@
+name: no-output
+description: A template with step returning no output
+title_format: "[test] no output"
+auto_runnable: true
+steps:
+    stepOne:
+        description: first step
+        idempotent: true
+        retry_pattern: seconds
+        action:
+            type: echo
+            base_output: {foobar: "buzz"}
+            configuration: {}