Consider .json as a fallback on FlatFileSchemaResolver

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

src/jsonschema/resolver.cc

@@ -136,7 +136,14 @@ auto FlatFileSchemaResolver::reidentify(const std::string &schema,
 auto FlatFileSchemaResolver::operator()(std::string_view identifier) const
     -> std::optional<JSON> {
   const std::string string_identifier{to_lowercase(identifier)};
-  const auto result{this->schemas.find(string_identifier)};
+  auto result{this->schemas.find(string_identifier)};
+
+  // Try with a `.json` extension (if not already) as a fallback, given
+  // how common that case is when using a file-based resolver
+  if (result == this->schemas.cend() && !string_identifier.ends_with(".json")) {
+    result = this->schemas.find(string_identifier + ".json");
+  }
+
   if (result != this->schemas.cend()) {
     auto schema{sourcemeta::jsontoolkit::from_file(result->second.path)};
     assert(sourcemeta::jsontoolkit::is_schema(schema));

test/jsonschema/jsonschema_flat_file_resolver_test.cc

@@ -48,6 +48,30 @@ TEST(JSONSchema_FlatFileSchemaResolver, single_schema_with_default_dialect) {
             expected);
 }
 
+TEST(JSONSchema_FlatFileSchemaResolver, no_json_extension_on_insert) {
+  sourcemeta::jsontoolkit::FlatFileSchemaResolver resolver;
+  const auto schema_path{std::filesystem::path{SCHEMAS_PATH} /
+                         "2020-12-without-extension.json"};
+  const auto &identifier{resolver.add(schema_path)};
+  EXPECT_EQ(identifier, "https://www.sourcemeta.com/2020-12-without-extension");
+  EXPECT_TRUE(resolver("https://www.sourcemeta.com/2020-12-without-extension")
+                  .has_value());
+  EXPECT_EQ(
+      resolver("https://www.sourcemeta.com/2020-12-without-extension").value(),
+      sourcemeta::jsontoolkit::from_file(schema_path));
+}
+
+TEST(JSONSchema_FlatFileSchemaResolver, no_json_extension_on_lookup) {
+  sourcemeta::jsontoolkit::FlatFileSchemaResolver resolver;
+  const auto schema_path{std::filesystem::path{SCHEMAS_PATH} /
+                         "2020-12-id.json"};
+  const auto &identifier{resolver.add(schema_path)};
+  EXPECT_EQ(identifier, "https://www.sourcemeta.com/2020-12-id.json");
+  EXPECT_TRUE(resolver("https://www.sourcemeta.com/2020-12-id").has_value());
+  EXPECT_EQ(resolver("https://www.sourcemeta.com/2020-12-id").value(),
+            sourcemeta::jsontoolkit::from_file(schema_path));
+}
+
 TEST(JSONSchema_FlatFileSchemaResolver, single_schema_anonymous_with_default) {
   sourcemeta::jsontoolkit::FlatFileSchemaResolver resolver;
   const auto schema_path{std::filesystem::path{SCHEMAS_PATH} /

test/jsonschema/schemas/2020-12-without-extension.json

@@ -0,0 +1,4 @@
+{
+  "$id": "https://www.sourcemeta.com/2020-12-without-extension",
+  "$schema": "https://json-schema.org/draft/2020-12/schema"
+}