githubpages: support custom domains

Github Pages allows you to link a custom domain to your Github Pages
site by adding a `CNAME` file at the top-level of your `docs` directory.
The `githubpages` extension already inserts a `.nojekyll` file in the
`docs` directory, so it's a good place to add support for this `CNAME`
file as well.

1 files changed, 15 insertions, 0 deletions

diff --git a/tests/test_ext_githubpages.py b/tests/test_ext_githubpages.py
index 21b101b73..450a25498 100644
--- a/tests/test_ext_githubpages.py
+++ b/tests/test_ext_githubpages.py
@@ -15,3 +15,18 @@ import pytest
 def test_githubpages(app, status, warning):
     app.builder.build_all()
     assert (app.outdir / '.nojekyll').exists()
+    assert not (app.outdir / 'CNAME').exists()
+
+
+@pytest.mark.sphinx('html', testroot='ext-githubpages', confoverrides={'html_baseurl': 'https://sphinx-doc.github.io'})
+def test_no_cname_for_github_io_domain(app, status, warning):
+    app.builder.build_all()
+    assert (app.outdir / '.nojekyll').exists()
+    assert not (app.outdir / 'CNAME').exists()
+
+
+@pytest.mark.sphinx('html', testroot='ext-githubpages', confoverrides={'html_baseurl': 'https://sphinx-doc.org'})
+def test_cname_for_custom_domain(app, status, warning):
+    app.builder.build_all()
+    assert (app.outdir / '.nojekyll').exists()
+    assert (app.outdir / 'CNAME').text() == 'sphinx-doc.org'