Improve auto-generated docstrings of process variables (#130)

* improve var details formatting

* update release notes

doc/whats_new.rst

@@ -16,6 +16,8 @@ Enhancements
   from model variables' metadata (:issue:`126`).
 - Single-model parallelism now supports Dask's multi-processes or distributed
   schedulers, although this is still limited and rarely optimal (:issue:`127`).
+- Improved auto-generated docstrings of variables declared in process classes
+  (:issue:`130`).
 
 Bug fixes
 ~~~~~~~~~

xsimlab/formatting.py

@@ -1,6 +1,8 @@
 """Formatting utils and functions."""
 import textwrap
 
+import attr
+
 from .utils import variables_dict
 from .variable import VarIntent, VarType
 
@@ -85,23 +87,53 @@ def _summarize_var(var, process, col_width):
 
 
 def var_details(var, max_line_length=70):
-    var_metadata = var.metadata.copy()
+    meta = var.metadata
+    subsections = []
+
+    if meta["description"]:
+        wrapped_descr = textwrap.fill(
+            meta["description"].capitalize(), width=max_line_length
+        )
+        subsections.append(wrapped_descr)
+    else:
+        subsections.append("No description given")
 
-    description = textwrap.fill(
-        var_metadata.pop("description").capitalize(), width=max_line_length
-    )
-    if not description:
-        description = "(no description given)"
+    info = [f"- type : ``{meta['var_type'].value}``"]
 
-    detail_items = [
-        ("type", var_metadata.pop("var_type").value),
-        ("intent", var_metadata.pop("intent").value),
-    ]
-    detail_items += list(var_metadata.items())
+    if meta["var_type"] is VarType.FOREIGN:
+        ref_cls = meta["other_process_cls"]
+        ref_var = meta["var_name"]
+        info.append(f"- reference variable : :attr:`{ref_cls.__qualname__}.{ref_var}`")
+
+    info.append(f"- intent : ``{meta['intent'].value}``")
+
+    if meta.get("dims", False):
+        info.append("- dimensions : " + " or ".join(f"{d!r}" for d in meta["dims"]))
+
+    if meta.get("groups", False):
+        info.append("- groups : " + ", ".join(meta["groups"]))
+
+    if var.default != attr.NOTHING:
+        info.append(f"- default value : {var.default}")
+
+    if meta.get("static", False):
+        info.append("- static : ``True``")
+
+    subsections.append("Variable properties:\n\n" + "\n".join(info))
+
+    if meta.get("attrs", False):
+        subsections.append(
+            "Other attributes:\n\n"
+            + "\n".join(f"- {k} : {v}" for k, v in meta["attrs"].items())
+        )
 
-    details = "\n".join([f"- {k} : {v}" for k, v in detail_items])
+    if meta.get("encoding", False):
+        subsections.append(
+            "Encoding options:\n\n"
+            + "\n".join(f"- {k} : {v}" for k, v in meta["encoding"].items())
+        )
 
-    return description + "\n\n" + details + "\n"
+    return "\n\n".join(subsections) + "\n"
 
 
 def add_attribute_section(process, placeholder="{{attributes}}"):

xsimlab/tests/fixture_process.py

@@ -85,13 +85,11 @@ def in_var_details():
         """\
     Input variable
 
-    - type : variable
-    - intent : in
-    - dims : (('x',), ('x', 'y'))
-    - groups : ()
-    - static : False
-    - attrs : {}
-    - encoding : {}
+    Variable properties:
+
+    - type : ``variable``
+    - intent : ``in``
+    - dimensions : ('x',) or ('x', 'y')
     """
     )
 

xsimlab/tests/test_formatting.py

@@ -1,5 +1,7 @@
 from textwrap import dedent
 
+import attr
+
 import xsimlab as xs
 from xsimlab.formatting import (
     add_attribute_section,
@@ -32,15 +34,67 @@ def test_wrap_indent():
     assert wrap_indent(text, length=1) == expected
 
 
-def test_var_details(example_process_obj):
-    var = xs.variable(dims="x", description="a variable")
+def test_var_details():
+    @xs.process
+    class P:
+        var = xs.variable(
+            dims=[(), "x"],
+            description="a variable",
+            default=0,
+            groups=["g1", "g2"],
+            static=True,
+            attrs={"units": "m"},
+            encoding={"fill_value": -1},
+        )
+        var2 = xs.variable()
+
+    var_details_str = var_details(attr.fields(P).var)
+
+    expected = dedent(
+        """\
+        A variable
+
+        Variable properties:
 
-    var_details_str = var_details(var)
+        - type : ``variable``
+        - intent : ``in``
+        - dimensions : () or ('x',)
+        - groups : g1, g2
+        - default value : 0
+        - static : ``True``
 
-    assert var_details_str.strip().startswith("A variable")
-    assert "- type : variable" in var_details_str
-    assert "- intent : in" in var_details_str
-    assert "- dims : (('x',),)" in var_details_str
+        Other attributes:
+
+        - units : m
+
+        Encoding options:
+
+        - fill_value : -1
+        """
+    )
+
+    assert var_details_str == expected
+
+    @xs.process
+    class PP:
+        var = xs.foreign(P, "var2")
+
+    var_details_str = var_details(attr.fields(PP).var)
+
+    expected = dedent(
+        """\
+        No description given
+
+        Variable properties:
+
+        - type : ``foreign``
+        - reference variable : :attr:`test_var_details.<locals>.P.var2`
+        - intent : ``in``
+        - dimensions : ()
+        """
+    )
+
+    assert var_details_str == expected
 
 
 @xs.process(autodoc=False)
@@ -72,24 +126,20 @@ def test_add_attribute_section():
     var1 : :class:`attr.Attribute`
         A variable
 
-        - type : variable
-        - intent : in
-        - dims : (('x',),)
-        - groups : ()
-        - static : False
-        - attrs : {}
-        - encoding : {}
+        Variable properties:
+
+        - type : ``variable``
+        - intent : ``in``
+        - dimensions : ('x',)
 
     var2 : :class:`attr.Attribute`
-        (no description given)
-
-        - type : variable
-        - intent : in
-        - dims : ((),)
-        - groups : ()
-        - static : False
-        - attrs : {}
-        - encoding : {}
+        No description given
+
+        Variable properties:
+
+        - type : ``variable``
+        - intent : ``in``
+        - dimensions : ()
     """
 
     assert add_attribute_section(WithoutPlaceHolder).strip() == expected.strip()

xsimlab/variable.py

@@ -407,11 +407,13 @@ def foreign(other_process_cls, var_name, intent="in"):
         "other_process_cls": other_process_cls,
         "var_name": var_name,
         "intent": VarIntent(intent),
-        "description": ref_var.metadata["description"],
-        "attrs": ref_var.metadata.get("attrs", {}),
-        "encoding": ref_var.metadata.get("encoding", {}),
     }
 
+    for meta_key in ["description", "dims", "attrs", "encoding"]:
+        ref_value = ref_var.metadata.get(meta_key)
+        if ref_value is not None:
+            metadata[meta_key] = ref_value
+
     if VarIntent(intent) == VarIntent.OUT:
         _init = False
         _repr = False