🐛 Fix needs.json read/write when no needs are present

sphinx_needs/external_needs.py

@@ -94,12 +94,17 @@ def load_external_needs(
             data = needs_json["versions"][version]
             needs = data["needs"]
         except KeyError:
-            uri = source.get("json_url", source.get("json_path", "unknown"))
-            raise NeedsExternalException(
-                clean_log(
-                    f"Version {version} not found in json file from {uri}: {list(needs_json.get('versions'))}"
+            if not needs_json.get("versions"):
+                # The versions dict is empty, so no needs were ever added.
+                data = {}
+                needs = {}
+            else:
+                uri = source.get("json_url", source.get("json_path", "unknown"))
+                raise NeedsExternalException(
+                    clean_log(
+                        f"Version {version} not found in json file from {uri}: {list(needs_json.get('versions'))}"
+                    )
                 )
-            )
 
         log.debug(f"Loading {len(needs)} needs.")
 

sphinx_needs/needsfile.py

@@ -179,6 +179,7 @@ def wipe_version(self, version: str) -> None:
             del self.needs_list["versions"][version]
 
     def _finalise(self) -> None:
+        self.update_or_add_version(self.current_version)
         # We need to rewrite some data, because this kind of data gets overwritten during needs.json import
         if not self.needs_config.reproducible_json:
             self.needs_list["created"] = datetime.now().isoformat()

tests/__snapshots__/test_needimport.ambr

@@ -2116,6 +2116,12 @@
   dict({
     'current_version': '1.0',
     'versions': dict({
+      '1.0': dict({
+        'needs': dict({
+        }),
+        'needs_amount': 0,
+        'needs_defaults_removed': True,
+      }),
     }),
   })
 # ---

tests/doc_test/doc_needs_builder_empty/conf.py

@@ -0,0 +1,3 @@
+project = "doc_needs_builder_empty"
+
+extensions = ["sphinx_needs"]

tests/doc_test/doc_needs_builder_empty/index.rst

@@ -0,0 +1,4 @@
+Empty doc
+=========
+
+There are no needs here.

tests/test_external.py

@@ -261,3 +261,52 @@ def test_external_allow_type_coercion_false(test_app):
     assert strip_colors(app._warning.getvalue()).splitlines() == [
         "WARNING: External need 'TEST_01' in 'needs.json' could not be added: 'tags' value is invalid: Invalid value for field 'tags': 'a,b,c' [needs.load_external_need]"
     ]
+
+
+@pytest.mark.parametrize(
+    "test_app",
+    [
+        {
+            "buildername": "html",
+            "files": [
+                ("index.rst", "Test\n====\n"),
+                (
+                    "conf.py",
+                    """
+extensions = ["sphinx_needs"]
+needs_external_needs = [{
+    'json_path':  'needs.json',
+    'base_url': 'http://my_company.com/docs/v1/',
+}]
+needs_build_json = True
+                 """,
+                ),
+            ],
+            "no_plantuml": True,
+        }
+    ],
+    indirect=True,
+)
+def test_external_empty_versions(test_app):
+    """Test external needs when the loaded needs.json has an empty versions dict."""
+    json_path = Path(test_app.srcdir) / "needs.json"
+    json_path.write_text(
+        json.dumps(
+            {
+                "current_version": "0.1.0",
+                "project": "foo",
+                "project_url": "https://bar",
+                "versions": {},
+            }
+        )
+    )
+
+    app = test_app
+    app.build()
+    assert app.statuscode == 0
+    assert not app._warning.getvalue()
+
+    needs_json = Path(test_app.outdir, "needs.json").read_text()
+    needs = json.loads(needs_json)
+    # the empty external needs should just be ignored without crashing.
+    assert "TEST_01" not in needs["versions"][""]["needs"]

tests/test_needs_builder.py

@@ -115,3 +115,23 @@ def test_needs_html_and_json(test_app):
             need_data_1 = needs_1["versions"]["1.0"]["needs"]
             need_data_2 = needs_2["versions"]["1.0"]["needs"]
             assert need_data_1 == need_data_2
+
+
+@pytest.mark.parametrize(
+    "test_app",
+    [{"buildername": "needs", "srcdir": "doc_test/doc_needs_builder_empty"}],
+    indirect=True,
+)
+def test_doc_needs_builder_empty(test_app):
+    app = test_app
+    app.build()
+
+    needs_list = json.loads(Path(app.outdir, "needs.json").read_text())
+    assert "current_version" in needs_list
+    assert needs_list["current_version"] == ""
+
+    version = needs_list["current_version"]
+    assert "versions" in needs_list
+    assert version in needs_list["versions"]
+    assert needs_list["versions"][version]["needs_amount"] == 0
+    assert needs_list["versions"][version]["needs"] == {}