[{"id":3681775,"web_url":"http://patchwork.ozlabs.org/comment/3681775/","msgid":"<87ik9gkifq.fsf@pond.sub.org>","list_archive_url":null,"date":"2026-04-24T05:59:05","subject":"Re: [PATCH v2] tests: add test for json-streamer.c error recovery","submitter":{"id":2645,"url":"http://patchwork.ozlabs.org/api/people/2645/","name":"Markus Armbruster","email":"armbru@redhat.com"},"content":"Paolo Bonzini writes:\n\n> Before rewriting the error recovery code to work in a push parsing\n> setup, make sure that we have tests for it.\n>\n> Cover various cases of invalid JSON, to check that structural\n> recovery based on balanced brackets and braces works; and\n> lexer-based recovery which documents \"\\f\" as a sure fire\n> way to reset the lexer.\n>\n> Signed-off-by: Paolo Bonzini \n> ---\n> tests/unit/check-json-parser.c | 159 +++++++++++++++++++++++++++++++++\n> tests/unit/meson.build | 1 +\n> 2 files changed, 160 insertions(+)\n> create mode 100644 tests/unit/check-json-parser.c\n>\n> diff --git a/tests/unit/check-json-parser.c b/tests/unit/check-json-parser.c\n> new file mode 100644\n> index 00000000000..5e833eac1f9\n> --- /dev/null\n> +++ b/tests/unit/check-json-parser.c\n> @@ -0,0 +1,159 @@\n> +/*\n> + * Unit tests for JSON Parser error recovery\n> + *\n> + * Copyright 2026 Red Hat\n> + * Author: Paolo Bonzini \n> + *\n> + * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.\n> + * See the COPYING.LIB file in the top-level directory.\n> + */\n> +\n> +/*\n> + * Missing tests:\n> + * - multiple JSON values in a single stream\n> + * - multiple invocations of json_message_parser_feed()\n> + * (does not really matter much because of how\n> + * json_lexer_feed() is implemented)\n> + * - most JSON types are only covered by check-json.c.\n> + */\n> +\n> +#include \"qemu/osdep.h\"\n> +\n> +#include \"qapi/error.h\"\n> +#include \"qobject/qbool.h\"\n> +#include \"qobject/json-parser.h\"\n> +\n> +typedef struct ParseResult {\n> + int errors;\n> + QObject *result;\n> +} ParseResult;\n> +\n> +static void parse_emit(void *opaque, QObject *json, Error *err)\n> +{\n> + ParseResult *r = opaque;\n> +\n> + g_assert_cmpint(!json, !=, !err);\n> + if (err) {\n> + r->errors++;\n> + error_free(err);\n> + } else {\n> + g_assert_null(r->result);\n> + qobject_unref(r->result);\n\nDo we still need the unref?\n\n> + r->result = json;\n> + }\n> +}\n> +\n> +static ParseResult do_parse(const char *input)\n> +{\n> + ParseResult r = { 0, NULL };\n> + JSONMessageParser parser;\n> +\n> + json_message_parser_init(&parser, parse_emit, &r, NULL);\n> + json_message_parser_feed(&parser, input, strlen(input));\n> + json_message_parser_flush(&parser);\n> + json_message_parser_destroy(&parser);\n> + return r;\n> +}\n> +\n> +static void check_result(const char *input, int expected_errors, QType expected_type)\n\nLine break after the second parameter would be easier to read. Not\nworth a respin.\n\n> +{\n> + ParseResult r = do_parse(input);\n> +\n> + g_assert_cmpint(r.errors, ==, expected_errors);\n> + g_assert_nonnull(r.result);\n> + g_assert_cmpint(qobject_type(r.result), ==, expected_type);\n> + qobject_unref(r.result);\n> +}\n> +\n> +static void check_result_error(const char *input, int expected_errors)\n> +{\n> + ParseResult r = do_parse(input);\n> +\n> + g_assert_cmpint(r.errors, ==, expected_errors);\n> + g_assert_null(r.result);\n> +}\n> +\n> +static void test_simple(void)\n> +{\n> + check_result(\"false\", 0, QTYPE_QBOOL);\n> +}\n> +\n> +static void test_whitespace(void)\n> +{\n> + check_result(\" false\", 0, QTYPE_QBOOL);\n> +}\n> +\n> +static void test_extra_closing_braces(void)\n> +{\n> + check_result(\"}}false\", 2, QTYPE_QBOOL);\n> +}\n> +\n> +static void test_bad_dict(void)\n> +{\n> + check_result(\"{ 'abc' }false\", 1, QTYPE_QBOOL);\n> +}\n> +\n> +static void test_trailing_comma(void)\n> +{\n> + check_result(\"[ 'abc', ]false\", 1, QTYPE_QBOOL);\n> +}\n> +\n> +static void test_lexer_recovery(void)\n> +{\n> + check_result(\"\\f{}\", 1, QTYPE_QDICT);\n> + check_result(\"\\f[]\", 1, QTYPE_QLIST);\n> + check_result(\"\\f:false\", 2, QTYPE_QBOOL);\n> + check_result(\"\\f,false\", 2, QTYPE_QBOOL);\n> +\n> + /*\n> + * Alphabetic characters do not start a new parsing. This is\n> + * slightly weird but it keeps the lexer simple and works well for\n> + * QMP (where valid input is a sequence of dictionaries).\n> + */\n> + check_result_error(\"\\ffalse\", 1);\n> + check_result_error(\"\\f'str'\", 1);\n> + check_result_error(\"\\f\\\"str\\\"\", 1);\n> +}\n> +\n> +static void test_lexer_recovery_nested(void)\n> +{\n> + check_result(\"{[{\\f{}\", 1, QTYPE_QDICT);\n> + check_result(\"{[{\\f[]\", 1, QTYPE_QLIST);\n> + check_result(\"{[{\\f:false\", 2, QTYPE_QBOOL);\n> + check_result(\"{[{\\f,false\", 2, QTYPE_QBOOL);\n> +\n> + /*\n> + * As in test_lexer_recovery, these do not produce a successful\n> + * parse after \\f.\n> + */\n> + check_result_error(\"{[{\\ffalse\", 1);\n> + check_result_error(\"{[{\\f'str'\", 1);\n> + check_result_error(\"{[{\\f\\\"str\\\"\", 1);\n> +}\n> +\n> +static void test_nested(void)\n> +{\n> + check_result(\"[{'a']}false\", 1, QTYPE_QBOOL);\n> +}\n> +\n> +static void test_nested_multiple(void)\n> +{\n> + check_result(\"[{'a']}[{'a']}false\", 2, QTYPE_QBOOL);\n> +}\n> +\n> +int main(int argc, char **argv)\n> +{\n> + g_test_init(&argc, &argv, NULL);\n> +\n> + g_test_add_func(\"/json-parser/simple\", test_simple);\n> + g_test_add_func(\"/json-parser/whitespace\", test_whitespace);\n> + g_test_add_func(\"/json-parser/error-recovery/extra-closing-braces\", test_extra_closing_braces);\n> + g_test_add_func(\"/json-parser/error-recovery/bad-dict\", test_bad_dict);\n> + g_test_add_func(\"/json-parser/error-recovery/trailing-comma\", test_trailing_comma);\n> + g_test_add_func(\"/json-parser/error-recovery/lexer\", test_lexer_recovery);\n> + g_test_add_func(\"/json-parser/error-recovery/lexer/nested\", test_lexer_recovery_nested);\n> + g_test_add_func(\"/json-parser/error-recovery/nested\", test_nested);\n> + g_test_add_func(\"/json-parser/error-recovery/nested/multiple\", test_nested_multiple);\n> +\n> + return g_test_run();\n> +}\n> diff --git a/tests/unit/meson.build b/tests/unit/meson.build\n> index 41e8b06c339..03d36748c73 100644\n> --- a/tests/unit/meson.build\n> +++ b/tests/unit/meson.build\n> @@ -10,6 +10,7 @@ tests = {\n> 'check-qnull': [],\n> 'check-qobject': [],\n> 'check-qjson': [],\n> + 'check-json-parser': [],\n> 'check-qlit': [],\n> 'test-error-report': [],\n> 'test-qobject-output-visitor': [testqapi],\n\nReviewed-by: Markus Armbruster ","headers":{"Return-Path":"","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (1024-bit key;\n unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256\n header.s=mimecast20190719 header.b=P+4YKutA;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org\n (client-ip=209.51.188.17; helo=lists1p.gnu.org;\n envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org;\n receiver=patchwork.ozlabs.org)"],"Received":["from lists1p.gnu.org (lists1p.gnu.org [209.51.188.17])\n\t(using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits))\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4g22P84gxXz1yDD\n\tfor ; Fri, 24 Apr 2026 16:00:11 +1000 (AEST)","from localhost ([::1] helo=lists1p.gnu.org)\n\tby lists1p.gnu.org with esmtp (Exim 4.90_1)\n\t(envelope-from )\n\tid 1wG9ZM-0008JK-Ur; Fri, 24 Apr 2026 01:59:16 -0400","from eggs.gnu.org ([2001:470:142:3::10])\n by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256)\n (Exim 4.90_1) (envelope-from ) id 1wG9ZM-0008J6-8y\n for qemu-devel@nongnu.org; Fri, 24 Apr 2026 01:59:16 -0400","from us-smtp-delivery-124.mimecast.com ([170.10.129.124])\n by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256)\n (Exim 4.90_1) (envelope-from ) id 1wG9ZJ-0001Vt-9z\n for qemu-devel@nongnu.org; Fri, 24 Apr 2026 01:59:16 -0400","from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com\n (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by\n relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3,\n cipher=TLS_AES_256_GCM_SHA384) id us-mta-499-EIeTt3jKMQGoPWbTBn8J4A-1; Fri,\n 24 Apr 2026 01:59:09 -0400","from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com\n (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12])\n (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest\n SHA256)\n (No client certificate requested)\n by mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS\n id 7BC4D180034D\n for ; Fri, 24 Apr 2026 05:59:08 +0000 (UTC)","from blackfin.pond.sub.org (unknown [10.44.22.30])\n by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with\n ESMTPS\n id E798619560B7\n for ; Fri, 24 Apr 2026 05:59:07 +0000 (UTC)","by blackfin.pond.sub.org (Postfix, from userid 1000)\n id 6650D21E6A28; Fri, 24 Apr 2026 07:59:05 +0200 (CEST)"],"DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com;\n s=mimecast20190719; t=1777010351;\n h=from:from:reply-to:subject:subject:date:date:message-id:message-id:\n to:to:cc:cc:mime-version:mime-version:content-type:content-type:\n in-reply-to:in-reply-to:references:references;\n bh=1cxC1OnqufF5ZuXFzPwntXThqyTdjBDee+5LsqdTJkg=;\n b=P+4YKutATbzdXl1flrCrs3Sn69x+UYSuFblb/IoIdk9XQpKtZL96bZTAxrIkRlWOuwUmbG\n KmyEDpfpgOm7KNnJNSKO+Ucv8dGrP49z1I2g6m2Sz3Mu31OaHMWsz0eVXPmbEaWH1k3BZy\n HjfMoPEB9cn8DCf+xxW3+HHbi5zTACg=","X-MC-Unique":"EIeTt3jKMQGoPWbTBn8J4A-1","X-Mimecast-MFC-AGG-ID":"EIeTt3jKMQGoPWbTBn8J4A_1777010348","From":"Markus Armbruster ","To":"Paolo Bonzini ","Cc":"qemu-devel@nongnu.org","Subject":"Re: [PATCH v2] tests: add test for json-streamer.c error recovery","In-Reply-To":"<20260423163509.502729-1-pbonzini@redhat.com> (Paolo Bonzini's\n message of \"Thu, 23 Apr 2026 18:35:09 +0200\")","References":"<20260423163509.502729-1-pbonzini@redhat.com>","Date":"Fri, 24 Apr 2026 07:59:05 +0200","Message-ID":"<87ik9gkifq.fsf@pond.sub.org>","User-Agent":"Gnus/5.13 (Gnus v5.13)","MIME-Version":"1.0","Content-Type":"text/plain","X-Scanned-By":"MIMEDefang 3.0 on 10.30.177.12","Received-SPF":"pass client-ip=170.10.129.124; envelope-from=armbru@redhat.com;\n helo=us-smtp-delivery-124.mimecast.com","X-Spam_score_int":"-20","X-Spam_score":"-2.1","X-Spam_bar":"--","X-Spam_report":"(-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001,\n DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1,\n RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001,\n SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no","X-Spam_action":"no action","X-BeenThere":"qemu-devel@nongnu.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"qemu development ","List-Unsubscribe":",\n ","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n ","Errors-To":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org","Sender":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org"}}]