fix(web): plugin config page survives stored values the schema outgrew (#578)

Two stored shapes broke the config form:

* A scalar under a field that is now an object. News' dynamic_duration
  was a boolean and is becoming an object; render_nested_section did
  `key in true` and the whole page failed to render. Look into dicts
  only, and carry a legacy boolean over as the object's `enabled`, so
  the next save upgrades it without switching the feature off.
* A custom feed logo with a path but no id. The template always emitted
  an empty `logo.id` input, which the save route parsed to null, failing
  the id's string type on every save. Emit it only when there is an id,
  as custom-feeds.js already does.

Co-authored-by: Claude Opus 5 <noreply@anthropic.com>

test/web_interface/test_plugin_config_legacy_values.py

@@ -0,0 +1,180 @@
+"""Stored values the current schema no longer describes must not break the form.
+
+Two cases from the news plugin:
+
+* ``global.dynamic_duration`` used to be a boolean and is now an object. An
+  install that has not saved since still holds ``true``; rendering the nested
+  section did ``key in true`` and the whole config page failed to load.
+* A custom feed logo stored with a ``path`` but no ``id``. The template always
+  emitted an empty ``logo.id`` input, which the save route parsed to ``None``
+  and the schema rejected (``Expected type string``) -- 400 on every save.
+"""
+
+import json
+import sys
+from html.parser import HTMLParser
+from pathlib import Path
+from unittest.mock import MagicMock
+
+import pytest
+from flask import Flask
+from werkzeug.datastructures import MultiDict
+
+PROJECT_ROOT = Path(__file__).parent.parent.parent
+sys.path.insert(0, str(PROJECT_ROOT))
+
+SCHEMA = {
+    "type": "object",
+    "properties": {
+        "enabled": {"type": "boolean", "default": True},
+        "global": {"type": "object", "properties": {
+            "dynamic_duration": {
+                "type": "object",
+                "properties": {
+                    "enabled": {"type": "boolean", "default": True},
+                    "min_duration_seconds": {"type": "integer", "default": 30,
+                                             "minimum": 10, "maximum": 300},
+                },
+                "additionalProperties": False,
+            },
+        }, "additionalProperties": False},
+        "feeds": {"type": "object", "properties": {
+            "custom_feeds": {
+                "type": "array",
+                "x-widget": "custom-feeds",
+                "items": {
+                    "type": "object",
+                    "properties": {
+                        "name": {"type": "string"},
+                        "url": {"type": "string"},
+                        "enabled": {"type": "boolean", "default": True},
+                        "logo": {"type": "object", "required": ["path"],
+                                 "properties": {"id": {"type": "string"},
+                                                "path": {"type": "string"}}},
+                    },
+                    "required": ["name", "url"],
+                    "additionalProperties": False,
+                },
+            },
+        }, "additionalProperties": False},
+    },
+    "required": ["enabled"],
+    "additionalProperties": False,
+}
+
+LOGO_PATH = "assets/plugins/news/uploads/verge.png"
+STORED = {
+    "enabled": True,
+    "global": {"dynamic_duration": True},
+    "feeds": {"custom_feeds": [{"name": "Verge",
+                                "url": "https://www.theverge.com/rss/index.xml",
+                                "enabled": True,
+                                "logo": {"path": LOGO_PATH}}]},
+}
+
+
+class _FormFields(HTMLParser):
+    """Collect what a browser would submit from the rendered form."""
+
+    def __init__(self):
+        super().__init__()
+        self.pairs = []
+
+    def handle_starttag(self, tag, attrs):
+        a = dict(attrs)
+        if tag != "input" or not a.get("name") or "disabled" in a:
+            return
+        if a.get("type") in ("checkbox", "radio") and "checked" not in a:
+            return
+        if a.get("type") in ("button", "submit", "file"):
+            return
+        self.pairs.append((a["name"], a.get("value", "")))
+
+
+def _render():
+    from jinja2 import Environment, FileSystemLoader, select_autoescape
+
+    env = Environment(
+        loader=FileSystemLoader(str(PROJECT_ROOT / "web_interface" / "templates")),
+        autoescape=select_autoescape(["html"]),
+    )
+    plugin = {"id": "demo", "name": "Demo", "description": "", "enabled": True,
+              "author": "me", "version": "1.0.0"}
+    return env.get_template("v3/partials/plugin_config.html").render(
+        plugin=plugin, schema=SCHEMA, config=json.loads(json.dumps(STORED)))
+
+
+@pytest.fixture
+def post(tmp_path):
+    from src.plugin_system.schema_manager import SchemaManager
+    from web_interface.blueprints import api_v3 as a
+
+    originals = {k: getattr(a.api_v3, k, None)
+                 for k in ("config_manager", "schema_manager", "plugin_manager")}
+
+    pdir = tmp_path / "plugins" / "demo"
+    pdir.mkdir(parents=True)
+    (pdir / "config_schema.json").write_text(json.dumps(SCHEMA), encoding="utf-8")
+
+    store = {"demo": json.loads(json.dumps(STORED))}
+    cm = MagicMock()
+    cm.load_config.side_effect = lambda: json.loads(json.dumps(store))
+    cm.get_raw_file_content.return_value = {}
+    cm.get_config_path.return_value = str(tmp_path / "config.json")
+
+    def _save(cfg, **_kw):
+        store.clear()
+        store.update(cfg)
+        return type("R", (), {"status": type("S", (), {"value": "success"})(),
+                              "message": None})()
+
+    cm.save_config_atomic.side_effect = _save
+
+    a.api_v3.config_manager = cm
+    a.api_v3.schema_manager = SchemaManager(plugins_dir=tmp_path / "plugins",
+                                            project_root=tmp_path)
+    pm = MagicMock()
+    pm.plugins = {}
+    pm.get_plugin.return_value = None
+    a.api_v3.plugin_manager = pm
+
+    app = Flask(__name__)
+    app.config["TESTING"] = True
+    app.register_blueprint(a.api_v3, url_prefix="/api/v3")
+    client = app.test_client()
+
+    def _post(pairs):
+        resp = client.post("/api/v3/plugins/config?plugin_id=demo",
+                           data=MultiDict(pairs))
+        return resp, store.get("demo", {})
+
+    try:
+        yield _post
+    finally:
+        for k, v in originals.items():
+            setattr(a.api_v3, k, v)
+
+
+def test_a_scalar_stored_under_an_object_field_still_renders():
+    html = _render()
+    assert 'name="global.dynamic_duration.min_duration_seconds"' in html
+
+
+def test_a_logo_without_an_id_posts_no_id_field():
+    parser = _FormFields()
+    parser.feed(_render())
+    names = [name for name, _ in parser.pairs]
+    assert "feeds.custom_feeds.0.logo.path" in names
+    assert "feeds.custom_feeds.0.logo.id" not in names
+
+
+def test_saving_that_form_succeeds_and_upgrades_the_legacy_value(post):
+    parser = _FormFields()
+    parser.feed(_render())
+    resp, cfg = post(parser.pairs)
+    assert resp.status_code == 200, resp.get_json()
+    assert isinstance(cfg["global"]["dynamic_duration"], dict)
+    # The legacy `true` was the on switch; upgrading must not turn it off.
+    assert cfg["global"]["dynamic_duration"]["enabled"] is True
+    assert cfg["global"]["dynamic_duration"]["min_duration_seconds"] == 30
+    assert cfg["feeds"]["custom_feeds"][0]["logo"] == {"path": LOGO_PATH}

web_interface/templates/v3/partials/plugin_config.html

@@ -613,7 +613,11 @@
                                                 {% if logo_path %}
                                                 <img src="/{{ logo_path }}" alt="Logo" loading="lazy" decoding="async" class="w-8 h-8 object-cover rounded border" id="{{ field_id }}_logo_preview_{{ item_index }}">
                                                 <input type="hidden" name="{{ full_key }}.{{ item_index }}.logo.path" value="{{ logo_path }}">
-                                                <input type="hidden" name="{{ full_key }}.{{ item_index }}.logo.id" value="{{ logo_value.get('id', '') }}">
+                                                {# Only when there is one, as custom-feeds.js does: a blank id
+                                                   is saved as null and fails the id's string type. #}
+                                                {% if logo_value.get('id') %}
+                                                <input type="hidden" name="{{ full_key }}.{{ item_index }}.logo.id" value="{{ logo_value.get('id') }}">
+                                                {% endif %}
                                                 {% else %}
                                                 <span class="text-xs text-gray-400">No logo</span>
                                                 {% endif %}
@@ -1108,8 +1112,21 @@
     {% set section_id = (plugin_id ~ '-section-' ~ full_key)|replace('.', '-')|replace('_', '-') %}
     {% set label = prop.title if prop.title else key|replace('_', ' ')|title %}
     {% set description = prop.description if prop.description else '' %}
-    {% set nested_value = value if value else {} %}
-    
+    {# Only a dict can be looked into. A schema that turns a legacy scalar into
+       an object (news' dynamic_duration: true -> {enabled, ...}) still finds
+       the scalar in config.json until the next save, and `key in true` is a
+       TypeError that takes down the whole config page. A legacy boolean was
+       the on/off switch the object's `enabled` now holds, so carry it over --
+       rendering {} would draw that checkbox unchecked and the next save would
+       quietly turn the feature off. The save then writes the object. #}
+    {% if value is mapping %}
+        {% set nested_value = value %}
+    {% elif value is boolean and 'enabled' in (prop.properties or {}) %}
+        {% set nested_value = {'enabled': value} %}
+    {% else %}
+        {% set nested_value = {} %}
+    {% endif %}
+
     <div class="nested-section border border-gray-300 rounded-lg mb-4">
         <button type="button" 
                 class="w-full bg-gray-100 hover:bg-gray-200 px-4 py-3 flex items-center justify-between text-left transition-colors rounded-t-lg"