1 files changed, 56 insertions, 0 deletions
diff --git a/tests/test_builder.py b/tests/test_builder.py
new file mode 100644
index 000000000..d58091e8d
--- /dev/null
+++ b/tests/test_builder.py
@@ -0,0 +1,56 @@
+# -*- coding: utf-8 -*-
+"""
+    test_builder
+    ~~~~~~~~
+
+    Test the Builder class.
+
+    :copyright: Copyright 2007-2018 by the Sphinx team, see AUTHORS.
+    :license: BSD, see LICENSE for details.
+"""
+import pytest
+
+
+@pytest.mark.sphinx('dummy', srcdir="test_builder")
+def test_incremental_reading(app):
+    # first reading
+    updated = app.builder.read()
+    assert set(updated) == app.env.found_docs == set(app.env.all_docs)
+
+    # test if exclude_patterns works ok
+    assert 'subdir/excluded' not in app.env.found_docs
+
+    # before second reading, add, modify and remove source files
+    (app.srcdir / 'new.txt').write_text('New file\n========\n')
+    app.env.all_docs['contents'] = 0  # mark as modified
+    (app.srcdir / 'autodoc.txt').unlink()
+
+    # second reading
+    updated = app.builder.read()
+
+    # "includes" and "images" are in there because they contain references
+    # to nonexisting downloadable or image files, which are given another
+    # chance to exist
+    assert set(updated) == set(['contents', 'new', 'includes', 'images'])
+    assert 'autodoc' not in app.env.all_docs
+    assert 'autodoc' not in app.env.found_docs
+
+
+@pytest.mark.sphinx('dummy')
+def test_env_read_docs(app):
+    """By default, docnames are read in alphanumeric order"""
+    def on_env_read_docs_1(app, env, docnames):
+        pass
+
+    app.connect('env-before-read-docs', on_env_read_docs_1)
+
+    read_docnames = app.builder.read()
+    assert len(read_docnames) > 2 and read_docnames == sorted(read_docnames)
+
+    def on_env_read_docs_2(app, env, docnames):
+        docnames.remove('images')
+
+    app.connect('env-before-read-docs', on_env_read_docs_2)
+
+    read_docnames = app.builder.read()
+    assert len(read_docnames) == 2