1 files changed, 77 insertions, 0 deletions
diff --git a/tests/test_domains/test_domain_py_canonical.py b/tests/test_domains/test_domain_py_canonical.py
new file mode 100644
index 0000000..3635cd1
--- /dev/null
+++ b/tests/test_domains/test_domain_py_canonical.py
@@ -0,0 +1,77 @@
+"""Tests the Python Domain"""
+
+from __future__ import annotations
+
+import pytest
+
+from sphinx import addnodes
+from sphinx.addnodes import (
+    desc,
+    desc_addname,
+    desc_annotation,
+    desc_content,
+    desc_name,
+    desc_sig_space,
+    desc_signature,
+)
+from sphinx.testing import restructuredtext
+from sphinx.testing.util import assert_node
+
+
+@pytest.mark.sphinx('html', testroot='domain-py', freshenv=True)
+def test_domain_py_canonical(app, status, warning):
+    app.build(force_all=True)
+
+    content = (app.outdir / 'canonical.html').read_text(encoding='utf8')
+    assert ('<a class="reference internal" href="#canonical.Foo" title="canonical.Foo">'
+            '<code class="xref py py-class docutils literal notranslate">'
+            '<span class="pre">Foo</span></code></a>' in content)
+    assert warning.getvalue() == ''
+
+
+def test_canonical(app):
+    text = (".. py:class:: io.StringIO\n"
+            "   :canonical: _io.StringIO")
+    domain = app.env.get_domain('py')
+    doctree = restructuredtext.parse(app, text)
+    assert_node(doctree, (addnodes.index,
+                          [desc, ([desc_signature, ([desc_annotation, ("class", desc_sig_space)],
+                                                    [desc_addname, "io."],
+                                                    [desc_name, "StringIO"])],
+                                  desc_content)]))
+    assert 'io.StringIO' in domain.objects
+    assert domain.objects['io.StringIO'] == ('index', 'io.StringIO', 'class', False)
+    assert domain.objects['_io.StringIO'] == ('index', 'io.StringIO', 'class', True)
+
+
+def test_canonical_definition_overrides(app, warning):
+    text = (".. py:class:: io.StringIO\n"
+            "   :canonical: _io.StringIO\n"
+            ".. py:class:: _io.StringIO\n")
+    restructuredtext.parse(app, text)
+    assert warning.getvalue() == ""
+
+    domain = app.env.get_domain('py')
+    assert domain.objects['_io.StringIO'] == ('index', 'id0', 'class', False)
+
+
+def test_canonical_definition_skip(app, warning):
+    text = (".. py:class:: _io.StringIO\n"
+            ".. py:class:: io.StringIO\n"
+            "   :canonical: _io.StringIO\n")
+
+    restructuredtext.parse(app, text)
+    assert warning.getvalue() == ""
+
+    domain = app.env.get_domain('py')
+    assert domain.objects['_io.StringIO'] == ('index', 'io.StringIO', 'class', False)
+
+
+def test_canonical_duplicated(app, warning):
+    text = (".. py:class:: mypackage.StringIO\n"
+            "   :canonical: _io.StringIO\n"
+            ".. py:class:: io.StringIO\n"
+            "   :canonical: _io.StringIO\n")
+
+    restructuredtext.parse(app, text)
+    assert warning.getvalue() != ""