Plate

Plate is a wrapper for Go's html/template (or text/template) that helps you test your template execution.

Plate makes it easier to check if the correct template has been rendered, whether the correct context has been passed to it and catch errors that occur.

Usage

First, rewrite your template variables to have the type plate.Executor. In short, transform this:

var tmpl *template.Template
// or
var templates map[string]*template.Template

To this:

var tmpl plate.Executor
// or
var templates map[string]plate.Executor

Your templates will implement plate.Executor automatically. Then, in your tests, wrap your template in a plate.Recorder:

recorder := plate.New(tmpl)
tmpl = recorder
// or
recorder := plate.New(tmpl)
templates["index.html"] = recorder

The template will execute as before, except for one thing: the recorder will accumulate the result of all executions: the output that template produced, the context passed to it and an error returned from an Execute*() call.

That information can be checked later to find out any faults in the execution of your template.

tmpl.Execute(...)
if recorder.LastExecution().Context == nil {
    t.Error("A nil context has been passed to the template")
}