--- a
+++ b/tests/utils/test_span_getters.py
@@ -0,0 +1,172 @@
+import pytest
+from confit import validate_arguments
+
+import edsnlp
+import edsnlp.pipes as eds
+from edsnlp.utils.span_getters import (
+    ContextWindow,
+    get_spans,
+    make_span_context_getter,
+    validate_span_setter,
+)
+
+
+def test_span_context_getter(lang):
+    nlp = edsnlp.blank(lang)
+    nlp.add_pipe("eds.normalizer")
+    nlp.add_pipe("eds.sentences")
+    nlp.add_pipe("eds.matcher", config={"terms": {"sentence": "sentence"}})
+    doc = nlp(
+        "This is a sentence. "
+        "This is another sentence. "
+        "This is a third one. "
+        "Last sentence."
+    )
+
+    span_getter = make_span_context_getter(
+        context_words=2,
+        context_sents=1,
+    )
+    assert [span_getter(s).text for s in doc.ents] == [
+        "This is a sentence. This",
+        "This is another sentence. This",
+        ". Last sentence.",
+    ]
+
+    span_getter = make_span_context_getter(
+        context_words=0,
+        context_sents=1,
+    )
+    assert [span_getter(s).text for s in doc.ents] == [
+        "This is a sentence.",
+        "This is another sentence.",
+        "Last sentence.",
+    ]
+
+    span_getter = make_span_context_getter(
+        context_words=0,
+        context_sents=2,
+    )
+    assert [span_getter(s).text for s in doc.ents] == [
+        "This is a sentence. This is another sentence.",
+        "This is a sentence. This is another sentence. This is a third one.",
+        "This is a third one. Last sentence.",
+    ]
+
+
+def test_span_getter_on_span():
+    nlp = edsnlp.blank("eds")
+    nlp.add_pipe(eds.sentences())
+    nlp.add_pipe(
+        eds.matcher(
+            terms={"animal": ["snake", "dog"]},
+            span_setter=["ents", "animals"],
+        )
+    )
+    doc = nlp(
+        "There was a snake. "
+        "His friend was a dog. "
+        "He liked baking cakes. "
+        "But since he had no hands, he was a bad baker. "
+    )
+    sents = list(doc.sents)
+    assert str(list(get_spans(sents[0], validate_span_setter("ents")))) == "[snake]"
+    assert str(list(get_spans(sents[0], validate_span_setter("animals")))) == "[snake]"
+    assert str(list(get_spans(doc[5:], validate_span_setter("animals")))) == "[dog]"
+    assert str(list(get_spans(doc[5:], validate_span_setter("*")))) == "[dog]"
+
+
+def test_span_context_getter_asymmetric(lang):
+    nlp = edsnlp.blank(lang)
+    nlp.add_pipe("eds.normalizer")
+    nlp.add_pipe("eds.sentences")
+    nlp.add_pipe("eds.matcher", config={"terms": {"animal": "kangaroo"}})
+    doc = nlp(
+        "This is a sentence. "
+        "This is another sentence with a kangaroo. "
+        "This is a third one. "
+        "Last sentence."
+    )
+
+    span_getter = make_span_context_getter(context_words=2, context_sents=0)
+    assert [span_getter(s).text for s in doc.ents] == [
+        "with a kangaroo. This",
+    ]
+
+    span_getter = make_span_context_getter(context_words=(2, 1), context_sents=0)
+    assert [span_getter(s).text for s in doc.ents] == [
+        "with a kangaroo.",
+    ]
+
+    span_getter = make_span_context_getter(context_words=(1, 2), context_sents=0)
+    assert [span_getter(s).text for s in doc.ents] == [
+        "a kangaroo. This",
+    ]
+
+    span_getter = make_span_context_getter(context_words=0, context_sents=(1, 2))
+    assert [span_getter(s).text for s in doc.ents] == [
+        "This is another sentence with a kangaroo. This is a third one.",
+    ]
+
+    span_getter = make_span_context_getter(context_words=0, context_sents=(2, 2))
+    assert [span_getter(s).text for s in doc.ents] == [
+        "This is a sentence. This is another sentence with a kangaroo. This is a third one."  # noqa: E501
+    ]
+
+    span_getter = make_span_context_getter(context_words=0, context_sents=(1, 1))
+    assert [span_getter(s).text for s in doc.ents] == [
+        "This is another sentence with a kangaroo."
+    ]
+
+    span_getter = make_span_context_getter(context_words=(1000, 0), context_sents=0)
+    assert [span_getter(s).text for s in doc.ents] == [
+        "This is a sentence. This is another sentence with a kangaroo"
+    ]
+
+    span_getter = make_span_context_getter(
+        context_words=(1000, 0), context_sents=(1, 2)
+    )
+    assert [span_getter(s).text for s in doc.ents] == [
+        "This is a sentence. This is another sentence with a kangaroo. This is a third one."  # noqa: E501
+    ]
+
+
+def test_context_getter_syntax():
+    @validate_arguments
+    def get_snippet(span, context: ContextWindow):
+        return context(span)
+
+    nlp = edsnlp.blank("eds")
+    nlp.add_pipe("eds.normalizer")
+    nlp.add_pipe("eds.sentences")
+    nlp.add_pipe("eds.matcher", config={"terms": {"dog": "dog"}})
+    doc = nlp(
+        "There was a snake. "
+        "His friend was a dog. "
+        "He liked baking cakes. "
+        "But since he had no hands, he was a bad baker. "
+    )
+
+    assert (
+        get_snippet(doc.ents[0], "words[-5:5]").text
+        == ". His friend was a dog. He liked baking cakes"
+    )
+
+    assert get_snippet(doc.ents[0], "words[-5:5] & sent").text == "His friend was a dog"
+
+    assert (
+        get_snippet(doc.ents[0], "words[-5:8] | sents[-1:1]").text
+        == "There was a snake. His friend was a dog. He liked baking cakes. "
+        "But since"
+    )
+
+
+def test_invalid_context_getter_syntax():
+    @validate_arguments
+    def apply_context(context: ContextWindow):
+        pass
+
+    apply_context("sents[-2:2]")
+
+    with pytest.raises(ValueError):
+        apply_context("stuff[-2:2]")