Handle wrong notebook format

nbcourse/pages.py

@@ -7,6 +7,7 @@ from pprint import pformat
 import jinja2
 from bs4 import BeautifulSoup
 import frontmatter
+import sys
 
 log = logging.getLogger(__name__)
 logging.basicConfig(level=logging.INFO)
@@ -62,14 +63,18 @@ class HomePage(Page):
         chapter_no = int(re.match(r'(\d+)\-', path.stem).group(1))
         nb = nbformat.read(str(path), as_version=4)
 
-        assert nb.cells[0].cell_type == 'markdown', nb.cells[0].cell_type
+        if nb.cells[0].cell_type != 'markdown':
+            log.error(f"The first cell of the notebook {path} should be Markdown type " + 
+                      f"({nb.cells[0].cell_type} instead).")
+            sys.exit()
         lines = nb.cells[0].source.splitlines()
         if lines[0].startswith('# '):
             header = lines[0][2:]
         elif len(lines) > 1 and lines[1].startswith('==='):
             header = lines[0]
         else:
-            assert False, "No heading found in {}".format(path)
+            log.error(f"No heading found in {path}")
+            sys.exit()
 
         assert path.suffix == '.ipynb', path
 

tests/test_nbcourse.py

@@ -17,22 +17,28 @@ def test_get_help_epilog():
     get_help_epilog()
 
 
-@pytest.fixture
-def create_project(tmpdir):
+def _create_project(tmpdir, sample=Path('sample')):
     """Create a sample nbcourse project"""
     p = tmpdir.mkdir("test_project")
     os.chdir(p)
     initialize()
 
     # Create a link to sample notebooks
-    nb = Path('sample')
-    nb.symlink_to(TESTS_PATH / 'sample', target_is_directory=True)
+    nb = Path(sample)
+    nb.symlink_to(TESTS_PATH / sample, target_is_directory=True)
 
     # Create a link to sample yaml file
     yaml_file = Path('nbcourse.yml')
     yaml_file.unlink()
-    yaml_file.symlink_to(TESTS_PATH / 'sample' / 'nbcourse.yml')
+    yaml_file.symlink_to(TESTS_PATH / sample / 'nbcourse.yml')
+
+@pytest.fixture
+def create_project(tmpdir):
+    _create_project(tmpdir)
 
+@pytest.fixture
+def create_wrong_project(tmpdir):
+    _create_project(tmpdir, sample=Path('wrong_sample'))
 
 def test_minimal_nbcourse(create_project):
     """Only test nbcourse object instantiation"""
@@ -64,3 +70,11 @@ def test_nbcourse_clean(create_project):
     course.conf['book']
     course.build(["-n 4"])
     course.build(["clean"])
+
+
+def test_nbcourse_wrong_build(create_wrong_project):
+    """Test sample build with nbcourse.yml sample file"""
+    course = NbCourse(Path('nbcourse.yml'))
+    course.conf['book']
+    with pytest.raises(SystemExit):
+        assert course.build(["-n 4"]) == 2

tests/wrong_sample/01-introduction.ipynb

+{
+ "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "The Zen of Python, by Tim Peters\n",
+      "\n",
+      "Beautiful is better than ugly.\n",
+      "Explicit is better than implicit.\n",
+      "Simple is better than complex.\n",
+      "Complex is better than complicated.\n",
+      "Flat is better than nested.\n",
+      "Sparse is better than dense.\n",
+      "Readability counts.\n",
+      "Special cases aren't special enough to break the rules.\n",
+      "Although practicality beats purity.\n",
+      "Errors should never pass silently.\n",
+      "Unless explicitly silenced.\n",
+      "In the face of ambiguity, refuse the temptation to guess.\n",
+      "There should be one-- and preferably only one --obvious way to do it.\n",
+      "Although that way may not be obvious at first unless you're Dutch.\n",
+      "Now is better than never.\n",
+      "Although never is often better than *right* now.\n",
+      "If the implementation is hard to explain, it's a bad idea.\n",
+      "If the implementation is easy to explain, it may be a good idea.\n",
+      "Namespaces are one honking great idea -- let's do more of those!\n"
+     ]
+    }
+   ],
+   "source": [
+    "import this"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Introduction\n",
+    "\n",
+    "![Python logo](fig/python-logo_full.png)\n",
+    "\n",
+    "Link to [another part of this notebook](#Just-a-subheading), and to [chapter 2](02-in-which-we.ipynb)."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "for a in range(1, 6):\n",
+    "    print(a, 'squared is', a**2)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "### Just a subheading\n",
+    "\n",
+    "Here's some content."
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "*These sample notebooks are from [bookbook project](https://github.com/takluyver/bookbook).*"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.7.6"
+  },
+  "toc": {
+   "base_numbering": 1,
+   "nav_menu": {},
+   "number_sections": true,
+   "sideBar": true,
+   "skip_h1_title": false,
+   "title_cell": "Table of Contents",
+   "title_sidebar": "Contents",
+   "toc_cell": false,
+   "toc_position": {},
+   "toc_section_display": true,
+   "toc_window_display": false
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 1
+}

tests/wrong_sample/02-in-which-we.ipynb

+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Part the Second\n",
+    "\n",
+    "Cross reference to [subheading in chapter 1](01-introduction.ipynb#Just-a-subheading).\n",
+    "\n",
+    "We would like to reference the external python file [helloworld.py](exos/helloworld.py)."
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.7.4"
+  },
+  "toc": {
+   "base_numbering": 1,
+   "nav_menu": {},
+   "number_sections": true,
+   "sideBar": true,
+   "skip_h1_title": false,
+   "title_cell": "Table of Contents",
+   "title_sidebar": "Contents",
+   "toc_cell": false,
+   "toc_position": {},
+   "toc_section_display": true,
+   "toc_window_display": false
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 1
+}
\ No newline at end of file

tests/wrong_sample/a_dir

+../sample/a_dir
\ No newline at end of file

tests/wrong_sample/exos

+../sample/exos/
\ No newline at end of file

tests/wrong_sample/fig

+../sample/fig/
\ No newline at end of file

tests/wrong_sample/nbcourse.yml

+title: A sample course
+slug_title: sample-course
+subtitle: Not very useful
+favicon: fig/favicon.ico
+book:
+  file: sample-course.pdf
+picture:
+    path: fig/python-logo_full.png
+    width: 300px
+    alt: Logo Python
+authors:
+  - name: Nobody
+    email: nobody@nowhere.com
+  - Somebody
+chapter_preview_only:
+  - 2
+links:
+  manual:
+    title: Manual
+    target: manual.html
+  binder:
+    title: Run
+    target: https://mybinder.org
+  book:
+    title: PDF version
+  gitlab:
+    title: Sources
+    target: https://gitlab.com
+  archive:
+    title: Complete archive
+license:
+  text: Content available under license
+  target: https://creativecommons.org/licenses/by-sa/4.0/
+  icon:
+    path: img/by-sa.svg
+    width: 70px
+local_reveal: True
+nb:
+  dir: 'wrong_sample'
+  material: 
+    - fig
+    - exos
+    - a_dir/a_file.txt