python - Flask 测试 - 如何检索传递给 Jinja 的变量？

Question

在 Flask 中，如何使用 render_template 测试返回到 Jinja 模板的变量？

@app.route('/foo/'):
def foo():
    return render_template('foo.html', foo='bar')

在这个例子中，我想测试 foo 是否等于 "bar"。

import unittest
from app import app

class TestFoo(unittest.TestCase):
    def test_foo(self):
        with app.test_client() as c:
            r = c.get('/foo/')
            # Prove that the foo variable is equal to "bar"

我该怎么做？

Answer 1

这可以使用 signals 来完成.我将在此处重现代码片段:

import unittest
from app import app
from flask import template_rendered
from contextlib import contextmanager

@contextmanager
def captured_templates(app):
    recorded = []
    def record(sender, template, context, **extra):
        recorded.append((template, context))
    template_rendered.connect(record, app)
    try:
        yield recorded
    finally:
        template_rendered.disconnect(record, app)

class TestFoo(unittest.TestCase):
    def test_foo(self):
        with app.test_client() as c:
            with captured_templates(app) as templates:
                r = c.get('/foo/')
                template, context = templates[0]
                self.assertEquals(context['foo'], 'bar')

---

这是另一种实现，它删除了 template 部分并将其转换为迭代器。

import unittest
from app import app
from flask import template_rendered
from contextlib import contextmanager

@contextmanager
def get_context_variables(app):
    recorded = []
    def record(sender, template, context, **extra):
        recorded.append(context)
    template_rendered.connect(record, app)
    try:
        yield iter(recorded)
    finally:
        template_rendered.disconnect(record, app)

class TestFoo(unittest.TestCase):
    def test_foo(self):
        with app.test_client() as c:
            with get_context_variables(app) as contexts:
                r = c.get('/foo/')
                context = next(context)
                self.assertEquals(context['foo'], 'bar')
                
                r = c.get('/foo/?foo=bar')
                context = next(context)
                self.assertEquals(context['foo'], 'foo')
                
                # This will raise a StopIteration exception because I haven't rendered
                # and new templates
                next(context)