add propagation tests

app_test.go

@@ -236,7 +236,7 @@ func ExampleApp_Run_shellComplete() {
 	os.Args = []string{"greet", fmt.Sprintf("--%s", genCompName())}
 
 	app := &App{
-		Name: "greet",
+		Name:                  "greet",
 		EnableShellCompletion: true,
 		Commands: []*Command{
 			{
@@ -503,7 +503,6 @@ func TestApp_Float64Flag(t *testing.T) {
 }
 
 func TestApp_ParseSliceFlags(t *testing.T) {
-	var parsedOption, firstArg string
 	var parsedIntSlice []int
 	var parsedStringSlice []string
 
@@ -518,8 +517,6 @@ func TestApp_ParseSliceFlags(t *testing.T) {
 				Action: func(c *Context) error {
 					parsedIntSlice = c.IntSlice("p")
 					parsedStringSlice = c.StringSlice("ip")
-					parsedOption = c.String("option")
-					firstArg = c.Args().First()
 					return nil
 				},
 			},

context_test.go

@@ -1,6 +1,7 @@
 package cli
 
 import (
+	"context"
 	"flag"
 	"sort"
 	"testing"
@@ -262,3 +263,24 @@ func TestContext_lookupFlagSet(t *testing.T) {
 		t.Fail()
 	}
 }
+
+// TestContextPropagation tests that
+// *cli.Context always has a valid
+// context.Context
+func TestContextPropagation(t *testing.T) {
+	ctx := NewContext(nil, nil, nil)
+	if ctx.Context == nil {
+		t.Fatal("expected a non nil context when no parent is present")
+	}
+	parent := NewContext(nil, nil, nil)
+	parent.Context = context.WithValue(context.Background(), "key", "val")
+	ctx = NewContext(nil, nil, parent)
+	val := ctx.Value("key")
+	if val == nil {
+		t.Fatal("expected a parent context to be inherited but got nil")
+	}
+	valstr, _ := val.(string)
+	if valstr != "val" {
+		t.Fatalf("expected the context value to be %q but got %q", "val", valstr)
+	}
+}