fix(validate): address review feedback (includes, pointer handling, tests, and behavior documentation)

Signed-off-by: Vaibhav mittal <vaibhavmittal929@gmail.com>

Author: Vaibhav701161

src/command_validate.cc

@@ -13,6 +13,7 @@
 #include <iostream>    // std::cerr
 #include <string>      // std::string
 #include <string_view> // std::string_view
+#include <utility>     // std::as_const
 
 #include "command.h"
 #include "configuration.h"
@@ -269,15 +270,19 @@ auto sourcemeta::jsonschema::validate(const sourcemeta::core::Options &options)
                         : sourcemeta::core::read_yaml_or_json(schema_path)};
 
   if (options.contains("path") && !options.at("path").empty()) {
+    // Invalid pointer syntax is handled by to_pointer(), consistent with
+    // --entrypoint behavior.
     const auto path_string{std::string{options.at("path").front()}};
     const auto pointer{sourcemeta::core::to_pointer(path_string)};
     const auto *const result{sourcemeta::core::try_get(schema, pointer)};
     // We intentionally reuse NotSchemaError here to align with existing CLI
     // error semantics without introducing a new error type.
     if (!result) {
-      throw NotSchemaError{schema_from_stdin ? stdin_path()
-                                             : schema_resolution_base};
+      throw NotSchemaError{schema_resolution_base};
     }
+    // Note: extracting a sub-schema may break $ref references outside the
+    // selected subtree. This is expected behavior for --path given the current
+    // CLI design.
     // `result` points into `schema`, so we must copy before reassigning to
     // avoid a use-after-free (the copy assignment destroys schema's storage
     // before reading from other when they alias).

test/CMakeLists.txt

@@ -246,6 +246,7 @@ add_jsonschema_test_unix(validate/pass_path_openapi)
 add_jsonschema_test_unix(validate/fail_path_not_found)
 add_jsonschema_test_unix(validate/fail_path_not_schema)
 add_jsonschema_test_unix(validate/fail_path_with_template)
+add_jsonschema_test_unix(validate/fail_path_ref_outside_subtree)
 add_jsonschema_test_unix(validate/pass_config_ignore)
 add_jsonschema_test_unix(validate/pass_config_ignore_with_cli)
 add_jsonschema_test_unix(validate/pass_stdin_instance)

test/validate/fail_path_ref_outside_subtree.sh

@@ -0,0 +1,37 @@
+#!/bin/sh
+
+set -o errexit
+set -o nounset
+
+TMP="$(mktemp -d)"
+clean() { rm -rf "$TMP"; }
+trap clean EXIT
+
+cat << 'EOF' > "$TMP/document.json"
+{
+  "components": {
+    "schemas": {
+      "Address": {
+        "$schema": "https://json-schema.org/draft/2020-12/schema",
+        "type": "object"
+      },
+      "User": {
+        "$schema": "https://json-schema.org/draft/2020-12/schema",
+        "$ref": "#/components/schemas/Address"
+      }
+    }
+  }
+}
+EOF
+
+cat << 'EOF' > "$TMP/instance.json"
+{}
+EOF
+
+"$1" validate "$TMP/document.json" "$TMP/instance.json" \
+  --path "/components/schemas/User" \
+  > /dev/null 2>&1 \
+  && EXIT_CODE="$?" || EXIT_CODE="$?"
+# Validation should fail when $ref points outside extracted subtree
+test "$EXIT_CODE" -ne "0"
+