Commit Graph
16 Commits
Author SHA1 Message Date
Niels Lohmann e6f32bd28a Stricter fuzzer checks and boundary-value tests for buffers (#5774)
* Check in the fuzzers that parsing without exceptions agrees

Each fuzzer driver now also parses its input with allow_exceptions =
false. That call must never throw a parse_error, must return a discarded
value where parsing with exceptions fails, and must return the same value
where it succeeds. Values are compared by their dump(), because NaN is
not equal to itself.

A plain !is_discarded() assertion, as suggested in #3642, would never
fail: the drivers parse with exceptions, so a result can never be
discarded.

tests/fuzzing.md describes the checks and notes that OSS-Fuzz and
CIFuzz already run LeakSanitizer, because their default address
sanitizer includes it.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Use JSON_HAS_RANGE_VIEW_CONVERSION in the range view regression tests

#5728 combined the JSON_HAS_RANGES and MinGW conditions into
JSON_HAS_RANGE_VIEW_CONVERSION, but three test guards still spelled
them out.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Test the serializer's buffers at their boundaries

The dump() indent overflow survived full line coverage because the tests
grew its buffer by only one step. This adds tests that land exactly on,
and one past, the limits of the other two serializer buffers:

- write_buffer (1024 bytes): strings of 1023, 1024 and 1025 bytes at the
  top level, and of 1022 and 1023 bytes inside an array, so that both
  guards in put_string() are hit at their boundary. Each is checked for
  dump() and for stream output.
- string_buffer (512 bytes, flushed when fewer than 13 bytes remain):
  runs of two-byte escapes, and a surrogate pair written with 14 bytes of
  room, right after a flush, and one escape later.
- The 8-byte bulk scan from the serializer side: 0 to 17 plain bytes
  followed by a quote, a control character, or a non-ASCII character.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Test the chunked string and binary reads of all binary formats

The binary readers read strings and binary values in chunks of 4096
bytes. Only CBOR tested lengths around that size. MessagePack, UBJSON,
BJData and BSON now round-trip lengths 0, 1, 4095, 4096, 4097, 8192 and
100000 from vector and pointer input, and must report a truncated
payload as a parse error.

UBJSON reads binary values as arrays of numbers, so it is tested with
strings only. BJData binary values reach the chunked read only in
Draft 3. BON8 decodes strings byte by byte and does not use this path.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-07 08:50:12 +02:00
Niels Lohmann b54ed188e6 Remove test debt: dead guards, discarded results, and unreferenced files (#5732)
* Run the README test case in JSON_FastTests jobs

The "README" test case was marked doctest::skip() when the tests
moved from Catch to doctest in 2019, where it replaced Catch's hidden
tag. It is not slow (17 assertions, about 0.00 s), but cmake/test.cmake
only passes --no-skip when JSON_FastTests is off, so the per-compiler
ci_test_*_cxxNN matrix, macOS, Windows Release/ARM, icpc, icpx and
nvhpc compiled the README examples without running them.

Drop the skip decorator so every job runs the case. Test-only change.

Part of #5713

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Remove stale clang ranges guards in unit-iterators2.cpp

The "algorithms" and "views" sections were guarded by clang/libstdc++
checks written for a clang 15 (04/2022) bug. The first guard's
condition contradicts its own comment: it skips clang+libc++ and
keeps clang+libstdc++. Both sections already sit inside
`#if JSON_HAS_RANGES`, which macro_scope.hpp excludes for the
toolchains these guards targeted, so the inner guards never let the
sections run on the platforms they meant to protect and are
redundant on the rest. Verified locally with Apple clang 21/libc++
and clang 16.0.6/libstdc++ 12 (Docker): both pass all 1355
assertions with the guards removed.

Part of #5713

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Fix copy-pasted CBOR half-float checks; enable stale encode checks

In the RFC 8949 Appendix A test case, the decode checks for
5.960464477539063e-8 (0xf9 0x00 0x01) and 0.00006103515625
(0xf9 0x04 0x00) were copy-pasted from the neighboring -4.0 example,
so those two half-float byte sequences were never actually decoded
and checked, and -4.0 was checked three times instead. The two
float32 encode checks for 100000.0 and 3.4028234663852886e+38 were
commented out before the writer supported emitting float32 and are
now verified to match byte for byte, so they are enabled. The
remaining commented-out half-precision to_cbor checks are collapsed
into a single explanatory comment, since the writer never emits
half-precision floats.

Part of #5713

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Assert on the result of STL container conversions in tests

The "object-like STL containers" and "array-like STL containers"
sections converted json values into std::map, unordered_map,
multimap, unordered_multimap, list, forward_list, array, valarray,
vector, deque, set and unordered_set and discarded the result, so
these ~60 conversions only proved that the code compiles and does
not throw; a conversion that dropped or reordered elements would
still pass. Bind each result and compare it against the expected
container. Also fix a copy-paste slip in the deque section
(`j2.get<std::deque<double>>()` instead of j3, so j3's doubles were
never converted to a deque), and remove the dead
`// CHECK(m5["one"] == "eins")` comments that referred to a variable
that did not exist by asserting the equivalent through the bound
result.

Part of #5713

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Deduplicate SaxCountdown and other test helpers across formats

SaxCountdown was copied byte-for-byte into six binary-format test
files (unit-cbor.cpp, unit-msgpack.cpp, unit-ubjson.cpp,
unit-bjdata.cpp, unit-bon8.cpp, unit-bson.cpp), about 370 redundant
lines. Move it into tests/src/sax_countdown.hpp (namespace utils,
alongside test_utils.hpp and round_trip_corpus.hpp) and include it
from all six.

trait_test_arg and the "value_in_range_of trait"
TEST_CASE_TEMPLATE_DEFINE were duplicated between unit-32bit.cpp and
unit-bjdata.cpp; the trait is a detail/meta trait, not specific to
either file. Move it into tests/src/value_in_range_of_test.hpp;
unit-32bit.cpp keeps its own include, since JSON_32bitTest=ONLY
builds only that file. Each file keeps its own
TEST_CASE_TEMPLATE_INVOKE list.

sax_no_exception and the "issue #2824" section were duplicated in
unit-regression2.cpp and unit-disabled_exceptions.cpp. Drop the copy
from unit-regression2.cpp; unit-disabled_exceptions.cpp already
covers the no-exceptions case that #2824 was about, and
ci_test_noexceptions reruns it.

No behavior change. Verified by building and running unit-cbor,
unit-msgpack, unit-ubjson, unit-bjdata, unit-bon8, unit-bson,
unit-32bit, unit-regression2 and unit-disabled_exceptions against
include/ (clang++ -std=c++11, ASan/UBSan where applicable); assertion
counts are unchanged from before the refactor.

Part of #5714

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Remove the unreferenced vendored libFuzzer

tests/thirdparty/Fuzzer (155 files, ~776 KB of vendored Apache-2.0
LLVM code from the 2016 OSS-Fuzz import) is not referenced by any
CMakeLists, Makefile or workflow: the fuzz drivers link against
-fsanitize=fuzzer or the repo's own
tests/src/fuzzer-driver_afl.cpp. Its vendored README only points at
llvm.org's own libFuzzer docs. Being dead code, it also adds noise
to the flawfinder code-scanning workflow, which scans the whole
tree. Remove the directory and its .reuse/dep5 entry.

Part of #5714

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Remove unreferenced 2016 benchmark and fuzz reports

tests/reports (1.6 MB) holds AFL status pages and plots from
2016-08-29 and 2016-10-02, and a nativejson-benchmark snapshot from
2016 with links to rawgit.com, which shut down in 2019. Nothing
references this directory: no doc, README section, script or
workflow points at it, and it describes a ten-years-old, pre-2.0
snapshot of the library.

Part of #5714

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Run the CBOR, MessagePack, BSON and BON8 round-trip invariants in CI

tests/src/round_trip_corpus.hpp exists so that the byte-stability
invariant the fuzzer drivers check also runs on a fixed corpus in CI,
instead of only at OSS-Fuzz. So far only the UBJSON and BJData drivers
had a matching unit test; the CBOR, MessagePack, BSON and BON8 drivers
assert the same invariant (assert(to_X(j2) == vec)) but nothing ran it
outside OSS-Fuzz.

Add "<FORMAT> round-trip invariants" test cases to unit-cbor.cpp,
unit-msgpack.cpp, unit-bson.cpp and unit-bon8.cpp, modeled on the
UBJSON case: seed j1 from the corpus (skipping values that do not
survive the format's own round trip, as the fuzzer drivers only ever
see values from_X() actually produced), then require from_X(to_X(j1))
not to throw and check to_X(j2) == to_X(j1). BSON only serializes
objects, so non-object corpus values are skipped. Update the comments
in round_trip_corpus.hpp and tests/fuzzing.md to name all six formats.

The stream-versus-contiguous check in the BON8 driver is left out, as
#5601 reworks it.

A local probe confirms no violations on the current corpus (CBOR 3849
checked, MessagePack 3909, BSON 2958, BON8 3841 - matching the counts
already recorded for this probe in the issue).

Closes #5714 item 1.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Fix fuzzer driver step lists to match the checks the code performs

The header comment of six of the seven binary-format fuzzer drivers
listed an invariant the code does not check: CBOR, MessagePack, BSON
and BON8 said "assert(j1 == j2)", but the code checks byte stability,
assert(to_X(j2) == vec). UBJSON and BJData still described the old
"assert(j1 == j2/j3/j4)" byte-exact check from before PR #5494 replaced
it with a use_size/use_type-aware round trip (UBJSON) and a
value-stability check (BJData); BJData's added paragraph already
explained the new check, but the step list above it did not.

Also remove a dead branch in fuzzer-parse_bson.cpp: from_bson() is
called with allow_exceptions = true, so it throws instead of returning
a discarded value, and the "if (j1.is_discarded()) return 0;" guard
could never trigger. Drop the unused <iostream> include from all seven
drivers and <sstream> from all but fuzzer-parse_bon8.cpp, which is the
only one that uses std::istringstream.

Overlaps #5601, which edits all seven drivers in the same hunks.

Closes #5714 item 4.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Silence the CMP0169 deprecation in cmake_fetch_content, fix stale guards

tests/cmake_fetch_content/project calls the single-argument
FetchContent_Populate(json) after FetchContent_Declare(), which CMake
3.30 deprecated as CMP0169. Since the project declares
cmake_minimum_required(VERSION 3.11...3.14), the policy stays unset,
so every configure with a current CMake prints the deprecation
warning. The test is kept on purpose: it is the only coverage of the
FetchContent_Populate + add_subdirectory pattern for CMake 3.11-3.13
users, which the docs still describe as supported. Explicitly set
CMP0169 to OLD, with a comment explaining why.

Also fix two stale version guards:
- tests/cmake_fetch_content/CMakeLists.txt guarded the test with
  VERSION_GREATER "3.11.0", which is dead now that tests/CMakeLists.txt
  requires CMake 3.13.
- tests/cmake_fetch_content2/CMakeLists.txt guarded with
  VERSION_GREATER "3.14.0", which skips exactly 3.14.0, the first
  version with FetchContent_MakeAvailable. Change it to
  VERSION_GREATER_EQUAL "3.14".

Verified locally: `ctest -R cmake_fetch_content` passes with CMake
4.1, and the CMP0169 deprecation warning that appeared before this
change is gone.

Closes #5714 item 5.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Make the CMake integration-test wrappers consistent

The six tests/cmake_* integration-test wrappers had drifted:

- Only cmake_import and cmake_import_minver forwarded
  -A "${CMAKE_GENERATOR_PLATFORM}" to the inner configure, and none
  forwarded -T "${CMAKE_GENERATOR_TOOLSET}". The Windows workflow
  configures the outer build with -A Win32 -T ClangCL, so without
  forwarding, the inner projects of cmake_add_subdirectory,
  cmake_fetch_content, cmake_fetch_content2 and
  cmake_target_include_directories built with the generator defaults
  instead of matching the outer build's platform and toolset. Forward
  both consistently from all six wrappers.
- cmake_fetch_content and cmake_fetch_content2 passed
  -Dnlohmann_json_source to their inner projects, which never read it
  (CMake warns "manually-specified variables were not used"); the
  inner projects fetch their own copy of the library instead. Drop it.
- tests/CMakeLists.txt set JSON_FORCED_GLOBAL_COMPILE_OPTIONS from the
  matching environment variable but never read the cache variable
  again; the lines right below it read $ENV{JSON_FORCED_GLOBAL_COMPILE_OPTIONS}
  directly, like the LINK_OPTIONS counterpart already does. Remove the
  dead set().

This changes which platform and toolset the Win32 and ClangCL CI jobs
build the four newly-forwarding wrappers' inner projects with, which
may surface new failures there; CI has to confirm those jobs.

Verified locally with Ninja (empty -A ""/-T "" is accepted): all 12
cmake_* tests still pass, and the inner fetch_content configures no
longer warn about the unused variable.

Closes #5714 item 6.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Turn the #972 fifo_map regression test into a real test

The #972 regression test in unit-regression1.cpp only built a
my_json array from a string literal (the original crash) and had no
CHECK, so the fifo_map object type it exists to demonstrate was never
exercised. Meanwhile the docs recommend fifo_map for keeping object
keys in insertion order (object_order.md, template_parameters.md),
and nothing tested that recommendation.

Extend the section: after the original array assignment, parse an
object with my_json::parse() (not via the "..."_json UDL, which
returns a plain nlohmann::json and would exercise the cross-basic_json
conversion constructor instead of the parser's own key insertion -
and, as tried locally, does not keep fifo order for this stateful
comparator) and check that dump() keeps insertion order, and that it
survives erase() and inserting a new key.

Also narrow thirdparty/fifo_map off the include path of every other
test-* target: it was a PUBLIC include directory of test_main, even
though unit-regression1.cpp is its only user. Add a small
fifo_map_include INTERFACE library with that include directory and
attach it to test-regression1 only via json_test_set_test_options().

Verified locally (test-regression1_cpp11, default build and
-fsanitize=address,undefined): the new checks pass; `git grep fifo_map
tests` still only finds unit-regression1.cpp and the vendored header.

Closes #5714 item 7.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Document the vendored doctest.h patch; fix stale doctest_compatibility.h comments

tests/thirdparty/doctest/doctest.h is doctest 2.4.12, imported in
#4771. Two weeks later, #4801 hand-edited translateActiveException()
to declare "String res;" inside the translator loop instead of before
it, so a translator that does not match does not leave a previous
translator's result in "res" for the next iteration to see. Nothing
recorded this, so re-vendoring doctest.h from upstream would silently
drop the fix. Add a comment at the patched site naming the version,
the PR and the reason, so a future re-vendor knows to re-apply it.

Also fix two stale comments in doctest_compatibility.h:
- The DOCTEST_THREAD_LOCAL comment referenced Xcode 6/7, which is no
  longer supported; reword it to explain why the define must stay
  regardless (it keeps doctest's own thread_local usage out of the way
  of the same Clang/MinGW crash that JSON_NO_THREAD_LOCAL works around
  in the library, see ci_test_no_thread_local).
- The <iosfwd> include's comment justified it with tests that define
  "private" as "public"; no test under tests/src does that any more
  (removed by #2352). Reword the comment instead of dropping the
  include, since confirming it is safe to drop needs the full CI
  matrix including MSVC 2015+.

Verified locally that tests/src/unit-readme.cpp still builds and
passes 17/17 with these headers.

Closes #5714 item 9.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Stop compiling unit-wstring.cpp out entirely on classic ICC

tests/src/unit-wstring.cpp wrapped the whole file in
#ifndef __INTEL_COMPILER, with the comment "ICPC errors out on
multibyte character sequences in source files". The ci_icpc job
(intel/oneapi-hpckit:2023.2.1) still exists, so that job ran none of
the wstring/u16string/u32string input adapter tests, including the
malformed-input checks #5704 (open) extends.

Only 9 lines contained non-ASCII bytes: the three *_is_utf16()/
*_is_utf32() probe functions, and three std::wstring/u16string/
u32string literals plus their narrow-string dump() expectations.
Rewrite all of them with \u/\U escapes in the wide/u16/u32 literals
and \x escapes (split into separate string-literal tokens so a
following byte is never read as part of the same hex escape, e.g.
"\xE1\x83\x85" "a") in the narrow ones. Remove the
#ifndef __INTEL_COMPILER/#endif guard along with it.

The *_is_utf16()/*_is_utf32() probes compared a raw multibyte literal
against an escape-based one to detect a compiler that misreads the
source file's encoding; with no raw literals left to misread, the
comparison is now tautological, so drop the probes and the "if"
guards around each SECTION's body instead of leaving them in as dead
checks.

The same non-ASCII-in-source-and-in-a-narrow-comparison pattern
existed once more in unit-deserialization.cpp's "Using _json with
char8_t literals #4945" test: a raw emoji character in a u8R"(...)"
literal, guarded by a check_utf8() that returned false for ICC (same
reason) and for Windows without the active UTF-8 code page. Rewrite
the literal with a \U escape and compare it against a \x-escaped
expectation instead of a second raw literal, and drop check_utf8()
and the now-unused <windows.h> include along with the guard.

Verified locally (clang, -std=c++11 and -std=c++20,
-fsanitize=address,undefined, and a plain build): test-wstring keeps
18/18 assertions and unit-deserialization keeps 466/466 (c++11) and
477/477 (c++20) assertions, matching this branch before the change
exactly - no coverage was gained or lost, only the source-encoding
dependency was removed. ci_icpc has to confirm classic ICC actually
builds and passes test-wstring now; if it does not, that is a real
finding, not a reason to restore the guard.

Overlaps #5704 (open), which edits unit-wstring.cpp inside the
previously-guarded region (an include near the top, checks in the
invalid-string sections, and a new section at the end).

Closes #5713 item 5.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 07:33:07 +02:00
Niels Lohmann 36c079149a Refuse to build the fuzzer drivers with NDEBUG (#5562)
The fuzzer drivers check their round trips with assert(), which NDEBUG
compiles away. The OSS-Fuzz build keeps assertions on today, but nothing
pins that: a build change that adds NDEBUG would silently turn every
round-trip check into a mere "does not crash" check. Each driver now
stops the build with an #error instead, and includes <cassert> itself
rather than relying on json.hpp.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-24 17:02:57 +02:00
Niels Lohmann 515d994acb 📄 adjust year (#5044)
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-01-01 20:00:39 +01:00
Niels Lohmann 54be9b04f0 📄 update REUSE (#4960) 2025-10-23 06:56:36 +02:00
Niels Lohmann 1705bfe914 🔖 set version to 3.12.0 (#4727)
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2025-04-11 10:41:14 +02:00
Niels Lohmann f06604fce0 Bump the copyright years (#4606)
* 📄 bump the copyright years

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* 📄 bump the copyright years

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* 📄 bump the copyright years

Signed-off-by: Niels Lohmann <niels.lohmann@gmail.com>

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
Signed-off-by: Niels Lohmann <niels.lohmann@gmail.com>
2025-01-19 17:04:17 +01:00
Niels Lohmann 1b9a9d1f21 Update licenses (#4521)
* 📄 update licenses

* 📄 update licenses
2024-11-29 17:38:42 +01:00
Niels Lohmann 9cca280a4d JSON for Modern C++ 3.11.3 (#4222) 2023-11-28 22:36:31 +01:00
Niels Lohmann f56c6e2e30 Update documentation for the next release (#4216) 2023-11-26 15:51:19 +01:00
Niels LohmannandFlorian Albrechtskirchinger 58bd97e2b1 Add clang-tools to required tools for ci_static_analysis_clang (#3724)
* 💚 add clang-tools to required tools for ci_static_analysis_clang

* 🚨 update Clang-Tidy warning selection

* 🚨 fix Clang-Tidy warnings

* 🚨 fix Clang-Tidy warnings

* 🚨 fix Clang-Tidy warnings

* 🚨 fix Clang-Tidy warnings

* 🚨 fix Clang-Tidy warnings

* 🚨 fix Clang-Tidy warnings

* 🚨 fix Clang-Tidy warnings

* 🚨 fix Clang-Tidy warnings

* 🚨 fix Clang-Tidy warnings

* 🚨 fix Clang-Tidy warnings

* 🚨 fix Clang-Tidy warnings (#3738)

* ⏪ revert fix

* ⏪ revert fix

* 🚨 fix Clang-Tidy warnings (#3739)

Co-authored-by: Florian Albrechtskirchinger <falbrechtskirchinger@gmail.com>
2022-09-13 12:58:26 +02:00
Niels Lohmann 9d69186291 🔖 set version to 3.11.2 2022-08-12 15:04:06 +02:00
Niels Lohmann f2020da0dd 🔖 set version to 3.11.1 2022-08-01 23:27:58 +02:00
Niels Lohmann ce0e13ccea 🔖 set version to 3.11.0 2022-07-31 23:19:06 +02:00
Niels LohmannandFlorian Albrechtskirchinger 527da54dcb Use REUSE framework (#3546)
* 📄 add licenses

* 👷 add REUSE compliance check

* 📝 add badge for REUSE

Co-authored-by: Florian Albrechtskirchinger <falbrechtskirchinger@gmail.com>
2022-07-20 12:38:07 +02:00
Niels Lohmann b21c345179 Reorganize directories (#3462)
* 🚚 move files
* 🚚 rename doc folder to docs
* 🚚 rename test folder to tests
2022-05-01 09:41:50 +02:00