Correctly repopulate anchor instance locations after references (#1561)

Signed-off-by: Juan Cruz Viotti <[email protected]>

src/core/jsonschema/frame.cc

@@ -223,7 +223,9 @@ static auto traverse_origin_instance_locations(
   }
 
   // Here, we want to get all the pointers of the subschemas that reference the
-  // current desired location
+  // current desired location.
+  // TODO: This is currently very slow, as we need to loop on every reference
+  // to brute force whether it points to the desired entry or not
 
   for (const auto &reference : frame.references()) {
     const auto subschema_pointer{reference.first.second.initial()};
@@ -856,12 +858,16 @@ auto SchemaFrame::analyse(const JSON &schema, const SchemaWalker &walker,
     }
 
     // This is guaranteed to be top-down
-    // TODO: Looping over the subschemas array means we never fix-up
-    // instance locations for anchors
-    for (auto &entry : subschemas) {
-      repopulate_instance_locations(
-          *this, this->instances_, subschemas, entry.first, entry.second,
-          this->instances_[entry.first], std::nullopt);
+    for (auto &entry : this->locations_) {
+      if (entry.second.type == SchemaFrame::LocationType::Pointer) {
+        continue;
+      }
+
+      const auto subschema{subschemas.find(entry.second.pointer)};
+      repopulate_instance_locations(*this, this->instances_, subschemas,
+                                    subschema->first, subschema->second,
+                                    this->instances_[entry.second.pointer],
+                                    std::nullopt);
     }
   }
 }

test/jsonschema/jsonschema_frame_2020_12_test.cc

@@ -2042,6 +2042,7 @@ TEST(JSONSchema_frame_2020_12, property_cross_ref) {
       },
       "bar": {
         "items": {
+          "$anchor": "foo",
           "additionalProperties": true
         }
       }
@@ -2053,7 +2054,7 @@ TEST(JSONSchema_frame_2020_12, property_cross_ref) {
   frame.analyse(document, sourcemeta::core::schema_official_walker,
                 sourcemeta::core::schema_official_resolver);
 
-  EXPECT_EQ(frame.locations().size(), 9);
+  EXPECT_EQ(frame.locations().size(), 11);
 
   EXPECT_FRAME_STATIC_2020_12_RESOURCE(
       frame, "https://www.sourcemeta.com/schema",
@@ -2094,6 +2095,11 @@ TEST(JSONSchema_frame_2020_12, property_cross_ref) {
       "https://www.sourcemeta.com/schema", "/properties/bar/items",
       "https://www.sourcemeta.com/schema", "/properties/bar/items",
       POINTER_TEMPLATES("/bar/~I~", "/foo/~I~"), "/properties/bar");
+  EXPECT_FRAME_STATIC_2020_12_POINTER(
+      frame, "https://www.sourcemeta.com/schema#/properties/bar/items/$anchor",
+      "https://www.sourcemeta.com/schema", "/properties/bar/items/$anchor",
+      "https://www.sourcemeta.com/schema", "/properties/bar/items/$anchor", {},
+      "/properties/bar/items");
   EXPECT_FRAME_STATIC_2020_12_SUBSCHEMA(
       frame,
       "https://www.sourcemeta.com/schema#/properties/bar/items/"
@@ -2105,6 +2111,12 @@ TEST(JSONSchema_frame_2020_12, property_cross_ref) {
       POINTER_TEMPLATES("/bar/~I~/~P~", "/foo/~I~/~P~"),
       "/properties/bar/items");
 
+  EXPECT_FRAME_STATIC_2020_12_ANCHOR(
+      frame, "https://www.sourcemeta.com/schema#foo",
+      "https://www.sourcemeta.com/schema", "/properties/bar/items",
+      "https://www.sourcemeta.com/schema", "/properties/bar/items",
+      POINTER_TEMPLATES("/bar/~I~", "/foo/~I~"), "/properties/bar");
+
   // References
 
   EXPECT_EQ(frame.references().size(), 2);