From 59da644db4e531aeff90560137f971c52fc2fd71 Mon Sep 17 00:00:00 2001 From: Colby Haskell Date: Tue, 31 Oct 2023 15:17:43 -0400 Subject: [PATCH] Add more specific error message when attempting to parse empty input (#4180) --- docs/mkdocs/docs/home/exceptions.md | 2 +- include/nlohmann/detail/input/parser.hpp | 14 +++++++++++++- single_include/nlohmann/json.hpp | 14 +++++++++++++- tests/src/unit-diagnostics.cpp | 2 +- tests/src/unit-regression1.cpp | 16 ++++++++-------- 5 files changed, 36 insertions(+), 12 deletions(-) diff --git a/docs/mkdocs/docs/home/exceptions.md b/docs/mkdocs/docs/home/exceptions.md index 0ecf8557c..a0fee9e33 100644 --- a/docs/mkdocs/docs/home/exceptions.md +++ b/docs/mkdocs/docs/home/exceptions.md @@ -139,7 +139,7 @@ This error indicates a syntax error while deserializing a JSON text. The error m No input: ``` - [json.exception.parse_error.101] parse error at line 1, column 1: syntax error while parsing value - unexpected end of input; expected '[', '{', or a literal + [json.exception.parse_error.101] parse error at line 1, column 1: attempting to parse an empty input; check that your input string or stream contains the expected JSON ``` Control character was not escaped: diff --git a/include/nlohmann/detail/input/parser.hpp b/include/nlohmann/detail/input/parser.hpp index 8acbd4fca..52154062d 100644 --- a/include/nlohmann/detail/input/parser.hpp +++ b/include/nlohmann/detail/input/parser.hpp @@ -341,13 +341,25 @@ class parser m_lexer.get_token_string(), parse_error::create(101, m_lexer.get_position(), exception_message(token_type::uninitialized, "value"), nullptr)); } + case token_type::end_of_input: + { + if (JSON_HEDLEY_UNLIKELY(m_lexer.get_position().chars_read_total == 1)) + { + return sax->parse_error(m_lexer.get_position(), + m_lexer.get_token_string(), + parse_error::create(101, m_lexer.get_position(), + "attempting to parse an empty input; check that your input string or stream contains the expected JSON", nullptr)); + } + return sax->parse_error(m_lexer.get_position(), + m_lexer.get_token_string(), + parse_error::create(101, m_lexer.get_position(), exception_message(token_type::literal_or_value, "value"), nullptr)); + } case token_type::uninitialized: case token_type::end_array: case token_type::end_object: case token_type::name_separator: case token_type::value_separator: - case token_type::end_of_input: case token_type::literal_or_value: default: // the last token was unexpected { diff --git a/single_include/nlohmann/json.hpp b/single_include/nlohmann/json.hpp index 14bc07d5f..dc58ca118 100644 --- a/single_include/nlohmann/json.hpp +++ b/single_include/nlohmann/json.hpp @@ -12441,13 +12441,25 @@ class parser m_lexer.get_token_string(), parse_error::create(101, m_lexer.get_position(), exception_message(token_type::uninitialized, "value"), nullptr)); } + case token_type::end_of_input: + { + if (JSON_HEDLEY_UNLIKELY(m_lexer.get_position().chars_read_total == 1)) + { + return sax->parse_error(m_lexer.get_position(), + m_lexer.get_token_string(), + parse_error::create(101, m_lexer.get_position(), + "attempting to parse an empty input; check that your input string or stream contains the expected JSON", nullptr)); + } + return sax->parse_error(m_lexer.get_position(), + m_lexer.get_token_string(), + parse_error::create(101, m_lexer.get_position(), exception_message(token_type::literal_or_value, "value"), nullptr)); + } case token_type::uninitialized: case token_type::end_array: case token_type::end_object: case token_type::name_separator: case token_type::value_separator: - case token_type::end_of_input: case token_type::literal_or_value: default: // the last token was unexpected { diff --git a/tests/src/unit-diagnostics.cpp b/tests/src/unit-diagnostics.cpp index 4f60a0f4d..85866a2fc 100644 --- a/tests/src/unit-diagnostics.cpp +++ b/tests/src/unit-diagnostics.cpp @@ -74,7 +74,7 @@ TEST_CASE("Better diagnostics") SECTION("Parse error") { json _; - CHECK_THROWS_WITH_AS(_ = json::parse(""), "[json.exception.parse_error.101] parse error at line 1, column 1: syntax error while parsing value - unexpected end of input; expected '[', '{', or a literal", json::parse_error); + CHECK_THROWS_WITH_AS(_ = json::parse(""), "[json.exception.parse_error.101] parse error at line 1, column 1: attempting to parse an empty input; check that your input string or stream contains the expected JSON", json::parse_error); } SECTION("Wrong type in update()") diff --git a/tests/src/unit-regression1.cpp b/tests/src/unit-regression1.cpp index 284ebd014..3d45a8d7d 100644 --- a/tests/src/unit-regression1.cpp +++ b/tests/src/unit-regression1.cpp @@ -722,7 +722,7 @@ TEST_CASE("regression tests 1") { std::ifstream f("file_not_found.json"); json _; - CHECK_THROWS_WITH_AS(_ = json::parse(f), "[json.exception.parse_error.101] parse error at line 1, column 1: syntax error while parsing value - unexpected end of input; expected '[', '{', or a literal", json::parse_error&); + CHECK_THROWS_WITH_AS(_ = json::parse(f), "[json.exception.parse_error.101] parse error at line 1, column 1: attempting to parse an empty input; check that your input string or stream contains the expected JSON", json::parse_error&); } SECTION("issue #367 - calling stream at EOF") @@ -736,7 +736,7 @@ TEST_CASE("regression tests 1") // ss is not at EOF; this yielded an error before the fix // (threw basic_string::append). No, it should just throw // a parse error because of the EOF. - CHECK_THROWS_WITH_AS(ss >> j, "[json.exception.parse_error.101] parse error at line 1, column 1: syntax error while parsing value - unexpected end of input; expected '[', '{', or a literal", json::parse_error&); + CHECK_THROWS_WITH_AS(ss >> j, "[json.exception.parse_error.101] parse error at line 1, column 1: attempting to parse an empty input; check that your input string or stream contains the expected JSON", json::parse_error&); } SECTION("issue #367 - behavior of operator>> should more closely resemble that of built-in overloads") @@ -745,7 +745,7 @@ TEST_CASE("regression tests 1") { std::stringstream ss; json j; - CHECK_THROWS_WITH_AS(ss >> j, "[json.exception.parse_error.101] parse error at line 1, column 1: syntax error while parsing value - unexpected end of input; expected '[', '{', or a literal", json::parse_error&); + CHECK_THROWS_WITH_AS(ss >> j, "[json.exception.parse_error.101] parse error at line 1, column 1: attempting to parse an empty input; check that your input string or stream contains the expected JSON", json::parse_error&); } SECTION("(whitespace)") @@ -765,7 +765,7 @@ TEST_CASE("regression tests 1") CHECK_NOTHROW(ss >> j); CHECK(j == 111); - CHECK_THROWS_WITH_AS(ss >> j, "[json.exception.parse_error.101] parse error at line 1, column 1: syntax error while parsing value - unexpected end of input; expected '[', '{', or a literal", json::parse_error&); + CHECK_THROWS_WITH_AS(ss >> j, "[json.exception.parse_error.101] parse error at line 1, column 1: attempting to parse an empty input; check that your input string or stream contains the expected JSON", json::parse_error&); } SECTION("one value + whitespace") @@ -788,7 +788,7 @@ TEST_CASE("regression tests 1") CHECK_NOTHROW(ss >> j); CHECK(j == 333); - CHECK_THROWS_WITH_AS(ss >> j, "[json.exception.parse_error.101] parse error at line 1, column 1: syntax error while parsing value - unexpected end of input; expected '[', '{', or a literal", json::parse_error&); + CHECK_THROWS_WITH_AS(ss >> j, "[json.exception.parse_error.101] parse error at line 1, column 1: attempting to parse an empty input; check that your input string or stream contains the expected JSON", json::parse_error&); } SECTION("three values") @@ -803,7 +803,7 @@ TEST_CASE("regression tests 1") CHECK_NOTHROW(ss >> j); CHECK(j == 333); - CHECK_THROWS_WITH_AS(ss >> j, "[json.exception.parse_error.101] parse error at line 1, column 1: syntax error while parsing value - unexpected end of input; expected '[', '{', or a literal", json::parse_error&); + CHECK_THROWS_WITH_AS(ss >> j, "[json.exception.parse_error.101] parse error at line 1, column 1: attempting to parse an empty input; check that your input string or stream contains the expected JSON", json::parse_error&); } SECTION("literals without whitespace") @@ -820,7 +820,7 @@ TEST_CASE("regression tests 1") CHECK_NOTHROW(ss >> j); CHECK(j == ""); - CHECK_THROWS_WITH_AS(ss >> j, "[json.exception.parse_error.101] parse error at line 1, column 1: syntax error while parsing value - unexpected end of input; expected '[', '{', or a literal", json::parse_error&); + CHECK_THROWS_WITH_AS(ss >> j, "[json.exception.parse_error.101] parse error at line 1, column 1: attempting to parse an empty input; check that your input string or stream contains the expected JSON", json::parse_error&); } SECTION("example from #529") @@ -833,7 +833,7 @@ TEST_CASE("regression tests 1") CHECK_NOTHROW(ss >> j); CHECK(j == json({{"three", 3}})); - CHECK_THROWS_WITH_AS(ss >> j, "[json.exception.parse_error.101] parse error at line 1, column 1: syntax error while parsing value - unexpected end of input; expected '[', '{', or a literal", json::parse_error&); + CHECK_THROWS_WITH_AS(ss >> j, "[json.exception.parse_error.101] parse error at line 1, column 1: attempting to parse an empty input; check that your input string or stream contains the expected JSON", json::parse_error&); } SECTION("second example from #529")