Fix FlatFileSchemaResolver messing up $recursiveRef (#1451)

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

src/jsonschema/relativize.cc

@@ -29,6 +29,12 @@ auto relativize(JSON &schema, const SchemaWalker &walker,
         continue;
       }
 
+      // In 2019-09, `$recursiveRef` can only be `#`, so there
+      // is nothing else we can possibly do
+      if (property.first == "$recursiveRef") {
+        continue;
+      }
+
       URI reference{property.second.to_string()};
       reference.relative_to(base);
       reference.canonicalize();

test/jsonschema/jsonschema_flat_file_resolver_test.cc

@@ -273,3 +273,28 @@ TEST(JSONSchema_FlatFileSchemaResolver, case_insensitive_reidentify) {
   EXPECT_TRUE(resolver("https://EXAMPLE.com").has_value());
   EXPECT_TRUE(resolver("https://example.com").has_value());
 }
+
+TEST(JSONSchema_FlatFileSchemaResolver, with_recursive_ref) {
+  sourcemeta::jsontoolkit::FlatFileSchemaResolver resolver;
+  const auto schema_path{std::filesystem::path{SCHEMAS_PATH} /
+                         "2019-09-recursive-ref.json"};
+
+  const sourcemeta::jsontoolkit::JSON expected =
+      sourcemeta::jsontoolkit::parse(R"JSON({
+    "$schema": "https://json-schema.org/draft/2019-09/schema",
+    "$id": "https://www.sourcemeta.com/2019-09-recursive-ref.json",
+    "$recursiveAnchor": true,
+    "additionalProperties": {
+      "$recursiveRef": "#"
+    }
+  })JSON");
+
+  const auto &identifier{resolver.add(schema_path)};
+  EXPECT_EQ(identifier,
+            "https://www.sourcemeta.com/2019-09-recursive-ref.json");
+  EXPECT_TRUE(resolver("https://www.sourcemeta.com/2019-09-recursive-ref.json")
+                  .has_value());
+  EXPECT_EQ(
+      resolver("https://www.sourcemeta.com/2019-09-recursive-ref.json").value(),
+      expected);
+}

test/jsonschema/jsonschema_relativize_test.cc

@@ -316,3 +316,29 @@ TEST(JSONSchema_relativize, 2020_12_2) {
 
   EXPECT_EQ(schema, expected);
 }
+
+TEST(JSONSchema_relativize, recursive_ref) {
+  auto schema = sourcemeta::jsontoolkit::parse(R"JSON({
+    "$schema": "https://json-schema.org/draft/2019-09/schema",
+    "$id": "https://www.sourcemeta.com",
+    "$recursiveAnchor": true,
+    "additionalProperties": {
+      "$recursiveRef": "#"
+    }
+  })JSON");
+
+  sourcemeta::jsontoolkit::relativize(
+      schema, sourcemeta::jsontoolkit::default_schema_walker,
+      sourcemeta::jsontoolkit::official_resolver);
+
+  const auto expected = sourcemeta::jsontoolkit::parse(R"JSON({
+    "$schema": "https://json-schema.org/draft/2019-09/schema",
+    "$id": "https://www.sourcemeta.com",
+    "$recursiveAnchor": true,
+    "additionalProperties": {
+      "$recursiveRef": "#"
+    }
+  })JSON");
+
+  EXPECT_EQ(schema, expected);
+}

test/jsonschema/schemas/2019-09-recursive-ref.json

@@ -0,0 +1,8 @@
+{
+  "$schema": "https://json-schema.org/draft/2019-09/schema",
+  "$id": "https://www.sourcemeta.com/2019-09-recursive-ref.json",
+  "$recursiveAnchor": true,
+  "additionalProperties": {
+    "$recursiveRef": "#"
+  }
+}