feat: compose stable product surfaces

tests/test_presentation_contract.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import unittest
+from dataclasses import replace
 
 from fastapi import FastAPI
 from fastapi.testclient import TestClient
@@ -10,7 +11,9 @@ from govoplan_core.core.modules import (
     FrontendModule,
     FrontendRoute,
     ModuleManifest,
+    ProductAvailabilityExplanation,
     ProductAreaContribution,
+    ProductSurfaceContribution,
     QuickAccessTool,
 )
 from govoplan_core.core.registry import PlatformRegistry, RegistryError
@@ -49,6 +52,26 @@ def presentation_manifest() -> ModuleManifest:
                     surface_ids=("example.route.main",),
                 ),
             ),
+            product_surfaces=(
+                ProductSurfaceContribution(
+                    id="work.examples",
+                    module_id="example",
+                    label="Examples",
+                    description="Review and update governed examples.",
+                    icon="list-checks",
+                    entry_path="/work/examples",
+                    route_path="/example",
+                    surface_ids=("example.route.main",),
+                    presentations=("task", "reader"),
+                    unavailable=ProductAvailabilityExplanation(
+                        reason="authorization",
+                        title="Examples are unavailable",
+                        description="Your current responsibility does not include examples.",
+                        resolution="Ask the responsible administrator to review your assignment.",
+                        responsible_role="Access administrator",
+                    ),
+                ),
+            ),
             quick_access_tools=(
                 QuickAccessTool(
                     id="example.summary",
@@ -121,6 +144,16 @@ class PresentationContractTests(unittest.TestCase):
         frontend = response.json()["modules"][0]["frontend"]
         self.assertEqual("1", frontend["presentation_contract_version"])
         self.assertEqual("work", frontend["product_areas"][0]["id"])
+        product_surface = frontend["product_surfaces"][0]
+        self.assertEqual("1", product_surface["contract_version"])
+        self.assertEqual("work.examples", product_surface["id"])
+        self.assertEqual("/work/examples", product_surface["entry_path"])
+        self.assertEqual("/example", product_surface["route_path"])
+        self.assertEqual(["task", "reader"], product_surface["presentations"])
+        self.assertEqual(
+            "authorization",
+            product_surface["unavailable"]["reason"],
+        )
         self.assertEqual("example.summary", frontend["quick_access_tools"][0]["id"])
         self.assertEqual("1", frontend["quick_access_tools"][0]["contract_version"])
         self.assertEqual(
@@ -132,6 +165,61 @@ class PresentationContractTests(unittest.TestCase):
             frontend["quick_access_tools"][0]["help_context_id"],
         )
 
+    def test_registry_rejects_product_surface_without_owner_route(self) -> None:
+        manifest = presentation_manifest()
+        frontend = manifest.frontend
+        assert frontend is not None
+        surface = frontend.product_surfaces[0]
+        invalid = ModuleManifest(
+            id=manifest.id,
+            name=manifest.name,
+            version=manifest.version,
+            frontend=FrontendModule(
+                module_id=manifest.id,
+                routes=frontend.routes,
+                product_surfaces=(
+                    ProductSurfaceContribution(
+                        id=surface.id,
+                        module_id=surface.module_id,
+                        label=surface.label,
+                        description=surface.description,
+                        icon=surface.icon,
+                        entry_path=surface.entry_path,
+                        route_path="/missing",
+                        surface_ids=surface.surface_ids,
+                        unavailable=surface.unavailable,
+                    ),
+                ),
+            ),
+        )
+        registry = PlatformRegistry()
+        registry.register(invalid)
+
+        with self.assertRaisesRegex(RegistryError, "unknown owner route"):
+            registry.validate()
+
+    def test_registry_rejects_product_alias_that_shadows_a_route(self) -> None:
+        manifest = presentation_manifest()
+        frontend = manifest.frontend
+        assert frontend is not None
+        surface = frontend.product_surfaces[0]
+        invalid = replace(
+            manifest,
+            frontend=replace(
+                frontend,
+                routes=(
+                    *frontend.routes,
+                    FrontendRoute(path="/shortcut", component="ShortcutPage"),
+                ),
+                product_surfaces=(replace(surface, aliases=("/shortcut",)),),
+            ),
+        )
+        registry = PlatformRegistry()
+        registry.register(invalid)
+
+        with self.assertRaisesRegex(RegistryError, "collides with a concrete route"):
+            registry.validate()
+
 
 if __name__ == "__main__":
     unittest.main()