Function TestHelp

flag_test.go:1007–1047

Test that -help invokes the usage message and returns ErrHelp.

(t *testing.T)

// Test that -help invokes the usage message and returns ErrHelp.
func TestHelp(t *testing.T) {
	helpCalled := false
	fs := NewFlagSet("help test", ContinueOnError)
	fs.Usage = func() { helpCalled = true }
	var flag bool
	fs.BoolVar(&flag, "flag", false, "regular flag")
	// Regular flag invocation should work
	err := fs.Parse([]string{"--flag=true"})
	if err != nil {
		t.Fatal("expected no error; got ", err)
	}
	if !flag {
		t.Error("flag was not set by --flag")
	}
	if helpCalled {
		t.Error("help called for regular flag")
		helpCalled = false // reset for next test
	}
	// Help flag should work as expected.
	err = fs.Parse([]string{"--help"})
	if err == nil {
		t.Fatal("error expected")
	}
	if err != ErrHelp {
		t.Fatal("expected ErrHelp; got ", err)
	}
	if !helpCalled {
		t.Fatal("help was not called")
	}
	// If we define a help flag, that should override.
	var help bool
	fs.BoolVar(&help, "help", false, "help flag")
	helpCalled = false
	err = fs.Parse([]string{"--help"})
	if err != nil {
		t.Fatal("expected no error for defined --help; got ", err)
	}
	if helpCalled {
		t.Fatal("help was called; should not have been for defined help flag")
	}
}

func TestNoInterspersed(t *testing.T) {
	f := NewFlagSet("test", ContinueOnError)