add nbexec test and enable nbconv to infer exporter type

src/cli/nbconv_click.py

@@ -17,10 +17,10 @@ def nbconv_click(in_file: str, exporter: str, out: str) -> None:
     :param out_file: The name of the output Jupyter notebook file.
     :note: The exporter type must be 'asciidoc', 'pdf', 'html', 'latex',
            'markdown', 'python', 'rst', 'script', or 'slides'.
-           pdf requires latex, 'notebook' does nothing,
-           slides need to served (not self-contained).
+           All formats except 'HTML' require pandoc.
+           Exporting to pdf requires latex.
     """
-    name, contents = nbconv(in_file, exporter) if exporter else nbconv(in_file)
+    name, contents = nbconv(in_file, exporter)
     if out:
         Path(out).write_text(contents)
     else:

src/nbless/nbconv.py

@@ -1,25 +1,39 @@
 #!/usr/bin/env python
 from pathlib import Path
-from typing import List, Union
+from typing import Tuple
 
 from nbconvert.exporters.base import get_exporter
 
 
-def nbconv(in_file: Union[str, Path], exporter: str = "python") -> List[str]:
+def nbconv(in_file: str, exporter: str = None) -> Tuple[str, str]:
     """Convert a notebook into various formats using ``nbformat`` exporters.
 
     :param in_file: The name of the input notebook file.
     :param exporter: The exporter that determines the output file type.
+    :return: A 2-tuple of the output file's 1) name and 2) contents.
     :note: The exporter type must be 'asciidoc', 'pdf', 'html', 'latex',
            'markdown', 'python', 'rst', 'script', or 'slides'.
-           pdf requires latex, 'notebook' does nothing,
-           slides need to served (not self-contained).
+           All formats except 'HTML' require pandoc.
+           Exporting to pdf requires latex.
     """
-    if isinstance(in_file, Path):
-        contents, resources = get_exporter(exporter)().from_file(in_file.open())
-    elif isinstance(in_file, str):
-        contents, resources = get_exporter(exporter)().from_filename(in_file)
-    else:
-        print("The in_file argument must be a string or pathlib Path object.")
-    out_name = Path(in_file).stem + resources.get("output_extension", ".txt")
+    in_file_path = Path(in_file)
+    if not exporter:
+        ext_exp_dict = {
+            '.asciidoc': 'asciidoc',
+            '.adoc': 'asciidoc',
+            '.asc': 'asciidoc',
+            '.pdf': 'pdf',
+            '.html': 'html',
+            '.tex': 'latex',
+            '.md': 'markdown',
+            '.py': 'python',
+            '.R': 'script',
+            '.rst': 'rst'
+        }
+        if in_file_path.suffix in ext_exp_dict:
+            exporter = ext_exp_dict[in_file_path.suffix]
+        else:
+            return "Unable to infer exporter type!"
+    contents, resources = get_exporter(exporter)().from_filename(in_file)
+    out_name = in_file_path.stem + resources.get("output_extension", ".txt")
     return [out_name, contents]

src/nbless/nbexec.py

@@ -6,7 +6,7 @@
 from nbformat.notebooknode import NotebookNode
 
 
-def nbexec(in_file: str, kernel: str = "python3") -> Tuple[str, NotebookNode]:
+def nbexec(in_file: str, kernel: str = "python3") -> NotebookNode:
     """Create an executed notebook without modifying the input notebook.
 
     :param in_file: The name of the Jupyter notebook file to be executed.

tests/test_nbless.py

@@ -2,9 +2,9 @@
 from typing import List
 
 import nbformat
-# import pytest
+import pytest
 
-from nbless import nbless, nbuild#, nbconv
+from nbless import nbless, nbuild, nbexec, nbconv
 
 
 def make_tempfiles(tmp_path: Path) -> List[str]:
@@ -40,19 +40,26 @@ def test_nbless(tmp_path: Path) -> None:
     for tempfile in make_tempfiles(tmp_path):
         assert nbless([tempfile]).cells[0].source == Path(tempfile).read_text()
 
-# Can't get Pandoc to work with Travis
 
-# @pytest.mark.parametrize('not_exporters', ['htm', 'ipython', 'markup'])
-# def test_raises(not_exporters, tmp_path: Path) -> None:
-#     """Make sure a ValueError is raised if nbconv() gets a bad exporter."""
-#     nb = make_temp_notebook(tmp_path)
-#     with pytest.raises(ValueError):
-#         nbconv(in_file=nb, exporter=not_exporters)
+def test_nbexec(tmp_path: Path) -> None:
+    """Run nbexec() to execute a temporary notebook file."""
+    for cell in nbexec(make_temp_notebook(tmp_path)).cells:
+        if cell.cell_type == 'code':
+            assert cell.execution_count
+            for output in cell.outputs:
+                assert output
 
+@pytest.mark.parametrize('not_exporters', ['htm', 'ipython', 'markup'])
+def test_raises(not_exporters, tmp_path: Path) -> None:
+    """Make sure a ValueError is raised if nbconv() gets a bad exporter."""
+    nb = make_temp_notebook(tmp_path)
+    with pytest.raises(ValueError):
+        nbconv(in_file=nb, exporter=not_exporters)
 
-# @pytest.mark.parametrize('exporters', ['html', 'asciidoc', 'rst'])
-# def test_nbconv(exporters, tmp_path: Path) -> None:
-#     """Convert ``tempfiles`` with each exporter in ``exporters``."""
-#     nb = make_temp_notebook(tmp_path)
-#     assert nbconv(in_file=nb,
-#                   exporter=exporters)[0].endswith("." + exporters)
+
+@pytest.mark.parametrize('exporters', ['html', 'asciidoc', 'rst'])
+def test_nbconv(exporters, tmp_path: Path) -> None:
+    """Convert ``tempfiles`` with each exporter in ``exporters``."""
+    nb = make_temp_notebook(tmp_path)
+    assert nbconv(in_file=nb,
+                  exporter=exporters)[0].endswith("." + exporters)