Jinja2 htmlfill ext

gistfile1.py

# htmlfill
with app.test_request_context('/'):
    html = render_template_string('''
        {%- autoescape true -%}
            {%- form 'user.signup' with {'a': 123, 'b': 456} -%}
                <input type="number" name="a"> {{- '' -}}
                <input type="number" name="b" value="2"> {{- '' -}}
                <input type="number" name="c" value="3">
            {%- endform -%}
        {%- endautoescape -%}
    ''')
expected = ('<form action="/users/" method="POST">'
            '<input type="number" name="a" value="123">'
            '<input type="number" name="b" value="456">'
            '<input type="number" name="c" value=""></form>')
assert html == expected