# blocktest [](https://travis-ci.org/jdkato/blocktest) [](https://crates.io/crates/blocktest)
`blocktest` is a "preprocessor" for markup (e.g., Markdown or reStructuredText) code blocks. It allows you to keep your code and prose separate without duplicating work. The idea is simple: `blocktest` extracts your code examples from within a larger testing context and adds them to your markup at user-specified locations.
For instance, let's say that you're writing this [section of the spaCy documentation](https://spacy.io/api/language#call). In this example, you want to include the following Python code snippet in your explanation:
```python
doc = nlp(u'An example sentence. Another sentence.')
assert (doc[0].text, doc[0].head.tag_) == ('An', 'NN')
```
With `blocktest`, you need two files:
1. A Python test file with the snippet inside of its test-related boilerplate:
```python
import spacy
nlp = spacy.load('en')
def test_example():
doc = nlp(u'An example sentence. Another sentence.') assert (doc[0].text, doc[0].head.tag_) == ('An', 'NN') ```
2. A markup file which specifies where to find the snippet:
````
<!-- example.md -->
```python
{{< id="example1" src="test_language.py" >}}
```
````
`blocktest` will scan `example.md` looking for *block definitions*, which specify a unique ID and a source file for each snippet. It will then extract the snippet (as indicated by the `<id> begin` / `<id> end` comments) from the source file and substitute it back into your markup. This allows you to write a thorough test suite for your code examples without having to maintain multiple copies of the same snippet.
## Getting Started