Follow up on #830 (#845)

* Follow-up on #830

* Update CHANGELOG.md

* In the contentsmanager we must use get() to load the pyproject.toml file

docs/CHANGELOG.md

@@ -4,6 +4,12 @@ Jupytext ChangeLog
 1.11.5+dev (2021-09-??)
 -----------------------
 
+**Added**
+- Jupytext can be configured through the `pyproject.toml` file. Thanks to Robin Brown for this contribution! (#828)
+
+**Fixed**
+- Added more test to make sure that notebooks can be trusted. In practice, notebooks could not be trusted in JupyterLab<3.0.13 because of the absence of cell ids (#826)
+
 
 1.11.5 (2021-08-31)
 -------------------

docs/config.md

@@ -72,6 +72,13 @@ or alternatively, using an explicit format list:
 formats = ["ipynb", "py:percent"]
 ```
 
+If you wish to use the `pyproject.toml` config file rather than `jupytext.toml`, you just need to
+create a `[tool.jupytext]` section in the `pyproject.toml` file, like here:
+```
+[tool.jupytext]
+formats = "ipynb,py:percent"
+```
+
 You can pair notebooks in trees with a `root_prefix` separated with three slashes, e.g.
 ```
 # Pair notebooks in subfolders of 'notebooks' to scripts in subfolders of 'scripts'
@@ -84,7 +91,7 @@ or alternatively, using a dict to map the prefix path to the format name:
 "notebooks/" = "ipynb"
 "scripts/" = "py:percent"
 ```
-Note that if you are using a `pyproject.toml` file with this dict format, you should make sure the table header is instead `[tool.jupytext.formats]`
+Note that if you are using a `pyproject.toml` file with this dict format, you should make sure the table header is instead `[tool.jupytext.formats]`.
 
 The `root_prefix` is matched with the top-most parent folder of the matching name, not above the Jupytext configuration file.
 

jupytext/config.py

@@ -356,7 +356,6 @@ def parse_jupytext_configuration_file(jupytext_config_file, stream=None):
             import toml
 
             doc = toml.loads(stream)
-            print(jupytext_config_file)
             if jupytext_config_file.endswith(PYPROJECT_FILE):
                 return doc["tool"]["jupytext"]
             else:

jupytext/contentsmanager.py

@@ -471,7 +471,12 @@ def get_config_file(self, directory):
 
             pyproject_path = directory + "/" + PYPROJECT_FILE
             if self.file_exists(pyproject_path):
-                return pyproject_path
+                import toml
+
+                model = self.get(pyproject_path, type="file")
+                doc = toml.loads(model["content"])
+                if doc.get("tool", {}).get("jupytext") is not None:
+                    return pyproject_path
 
             if not directory:
                 return None