Extend SchemaMapResolver::add to return a boolean value (#1630)

Signed-off-by: Juan Cruz Viotti <jv@jviotti.com>

Author: jviotti

src/core/jsonschema/include/sourcemeta/core/jsonschema_resolver.h

@@ -49,10 +49,11 @@ class SOURCEMETA_CORE_JSONSCHEMA_EXPORT SchemaMapResolver {
   /// Construct an empty resolver that has another schema resolver as a fallback
   SchemaMapResolver(const SchemaResolver &resolver);
 
-  /// Register a schema to the map resolver
+  /// Register a schema to the map resolver. Returns whether at least one
+  /// schema was imported into the resolver
   auto add(const JSON &schema,
            const std::optional<std::string> &default_dialect = std::nullopt,
-           const std::optional<std::string> &default_id = std::nullopt) -> void;
+           const std::optional<std::string> &default_id = std::nullopt) -> bool;
 
   /// Attempt to resolve a schema
   auto operator()(std::string_view identifier) const -> std::optional<JSON>;

src/core/jsonschema/resolver.cc

@@ -15,7 +15,7 @@ SchemaMapResolver::SchemaMapResolver(const SchemaResolver &resolver)
 auto SchemaMapResolver::add(const JSON &schema,
                             const std::optional<std::string> &default_dialect,
                             const std::optional<std::string> &default_id)
-    -> void {
+    -> bool {
   assert(sourcemeta::core::is_schema(schema));
 
   // Registering the top-level schema is not enough. We need to check
@@ -24,6 +24,7 @@ auto SchemaMapResolver::add(const JSON &schema,
   frame.analyse(schema, schema_official_walker, *this, default_dialect,
                 default_id);
 
+  bool added_any_schema{false};
   for (const auto &[key, entry] : frame.locations()) {
     if (entry.type != SchemaFrame::LocationType::Resource) {
       continue;
@@ -58,7 +59,11 @@ auto SchemaMapResolver::add(const JSON &schema,
       error << "Cannot register the same identifier twice: " << key.second;
       throw SchemaError(error.str());
     }
+
+    added_any_schema = true;
   }
+
+  return added_any_schema;
 }
 
 auto SchemaMapResolver::operator()(std::string_view identifier) const

test/jsonschema/jsonschema_map_resolver_test.cc

@@ -26,7 +26,8 @@ TEST(JSONSchema_SchemaMapResolver, single_schema) {
     "$schema": "https://json-schema.org/draft/2020-12/schema"
   })JSON");
 
-  resolver.add(document);
+  const auto result{resolver.add(document)};
+  EXPECT_TRUE(result);
 
   EXPECT_TRUE(resolver("https://www.sourcemeta.com/test").has_value());
   EXPECT_EQ(resolver("https://www.sourcemeta.com/test").value(), document);
@@ -44,7 +45,9 @@ TEST(JSONSchema_SchemaMapResolver, single_schema_with_default_dialect) {
     "$schema": "https://json-schema.org/draft/2020-12/schema"
   })JSON");
 
-  resolver.add(document, "https://json-schema.org/draft/2020-12/schema");
+  const auto result{
+      resolver.add(document, "https://json-schema.org/draft/2020-12/schema")};
+  EXPECT_TRUE(result);
 
   EXPECT_TRUE(resolver("https://www.sourcemeta.com/test").has_value());
   EXPECT_EQ(resolver("https://www.sourcemeta.com/test").value(), expected);
@@ -62,7 +65,9 @@ TEST(JSONSchema_SchemaMapResolver, single_schema_anonymous_with_default) {
     "$schema": "https://json-schema.org/draft/2020-12/schema"
   })JSON");
 
-  resolver.add(document, std::nullopt, "https://www.sourcemeta.com/test");
+  const auto result{
+      resolver.add(document, std::nullopt, "https://www.sourcemeta.com/test")};
+  EXPECT_TRUE(result);
 
   EXPECT_TRUE(resolver("https://www.sourcemeta.com/test").has_value());
   EXPECT_EQ(resolver("https://www.sourcemeta.com/test").value(), expected);
@@ -76,9 +81,13 @@ TEST(JSONSchema_SchemaMapResolver, single_schema_idempotent) {
     "$schema": "https://json-schema.org/draft/2020-12/schema"
   })JSON");
 
-  resolver.add(document);
-  resolver.add(document);
-  resolver.add(document);
+  const auto result_1{resolver.add(document)};
+  const auto result_2{resolver.add(document)};
+  const auto result_3{resolver.add(document)};
+
+  EXPECT_TRUE(result_1);
+  EXPECT_TRUE(result_2);
+  EXPECT_TRUE(result_3);
 
   EXPECT_TRUE(resolver("https://www.sourcemeta.com/test").has_value());
   EXPECT_EQ(resolver("https://www.sourcemeta.com/test").value(), document);
@@ -100,7 +109,8 @@ TEST(JSONSchema_SchemaMapResolver, duplicate_ids) {
     "type": "string"
   })JSON");
 
-  resolver.add(document_1);
+  const auto result{resolver.add(document_1)};
+  EXPECT_TRUE(result);
   EXPECT_THROW(resolver.add(document_2), sourcemeta::core::SchemaError);
 }
 
@@ -118,7 +128,8 @@ TEST(JSONSchema_SchemaMapResolver, embedded_resource) {
     }
   })JSON");
 
-  resolver.add(document);
+  const auto result{resolver.add(document)};
+  EXPECT_TRUE(result);
 
   const sourcemeta::core::JSON embedded = sourcemeta::core::parse_json(R"JSON({
     "$id": "https://www.sourcemeta.com/string",