The flags usage template from pflags has a trailing \n. We need to
include a newline in case there are no flags in our template. This will
trim the newline from the end of the flags from pflag and we can do it
right outselves.
This patch enables developers to add one to many template functions that
can be used by custom Usage and Help templates. Here is an example that
is included in the file cobra_test.go as the test function named
TestAddTemplateFunctions:
AddTemplateFunc("t", func() bool { return true })
AddTemplateFuncs(template.FuncMap{
"f": func() bool { return false },
"h": func() string { return "Hello," },
"w": func() string { return "world." }})
const usage = "Hello, world."
c := &Command{}
c.SetUsageTemplate(`{{if t}}{{h}}{{end}}{{if f}}{{h}}{{end}} {{w}}`)
if us := c.UsageString(); us != usage {
t.Errorf("c.UsageString() != \"%s\", is \"%s\"", usage, us)
}
In the above example four functions are added to the template function
map used when the Usage and Help text is generated from the templates
that enable custom logic as well as data injection during template
execution.
