treewide: parallel tests

Most tests already had no global state, however parallel was never enabled. This change enables it for all applicable tests.

Signed-off-by: Ophestra <cat@gensokyo.uk>

command/builder_test.go

@@ -7,6 +7,7 @@ import (
 )
 
 func TestBuild(t *testing.T) {
+	t.Parallel()
 	c := command.New(nil, nil, "test", nil)
 	stubHandler := func([]string) error { panic("unreachable") }
 

command/parse_test.go

@@ -14,6 +14,8 @@ import (
 )
 
 func TestParse(t *testing.T) {
+	t.Parallel()
+
 	testCases := []struct {
 		name      string
 		buildTree func(wout, wlog io.Writer) command.Command
@@ -251,6 +253,7 @@ Commands:
 	}
 	for _, tc := range testCases {
 		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
 			wout, wlog := new(bytes.Buffer), new(bytes.Buffer)
 			c := tc.buildTree(wout, wlog)
 

command/unreachable_test.go

@@ -6,15 +6,19 @@ import (
 )
 
 func TestParseUnreachable(t *testing.T) {
+	t.Parallel()
+
 	// top level bypasses name matching and recursive calls to Parse
 	// returns when encountering zero-length args
 	t.Run("zero-length args", func(t *testing.T) {
+		t.Parallel()
 		defer checkRecover(t, "Parse", "attempted to parse with zero length args")
 		_ = newNode(panicWriter{}, nil, " ", " ").Parse(nil)
 	})
 
 	// top level must not have siblings
 	t.Run("toplevel siblings", func(t *testing.T) {
+		t.Parallel()
 		defer checkRecover(t, "Parse", "invalid toplevel state")
 		n := newNode(panicWriter{}, nil, " ", "")
 		n.append(newNode(panicWriter{}, nil, "  ", " "))
@@ -23,6 +27,7 @@ func TestParseUnreachable(t *testing.T) {
 
 	// a node with descendents must not have a direct handler
 	t.Run("sub handle conflict", func(t *testing.T) {
+		t.Parallel()
 		defer checkRecover(t, "Parse", "invalid subcommand tree state")
 		n := newNode(panicWriter{}, nil, " ", " ")
 		n.adopt(newNode(panicWriter{}, nil, " ", " "))
@@ -32,6 +37,7 @@ func TestParseUnreachable(t *testing.T) {
 
 	// this would only happen if a node was matched twice
 	t.Run("parsed flag set", func(t *testing.T) {
+		t.Parallel()
 		defer checkRecover(t, "Parse", "invalid set state")
 		n := newNode(panicWriter{}, nil, " ", "")
 		set := flag.NewFlagSet("parsed", flag.ContinueOnError)