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simdjson-simdjson/tests/builder/static_reflection_fractured_json_tests.cpp
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Francisco Geiman Thiesen fc57c09cf0 Add FracturedJson formatting support for DOM serialization (#2580)
* Add FracturedJson formatting support for DOM serialization

Implements FracturedJson formatting as requested in issue #2576.
FracturedJson produces human-readable yet compact JSON output by
intelligently choosing between different layout strategies based on
content complexity, length, and structure similarity.

Key features:
- Four layout modes: inline, compact multiline, table, and expanded
- Structure analysis pass to compute metrics before formatting
- Table formatting for arrays of similar objects with column alignment
- Configurable options for line length, indentation, padding, etc.

New files:
- fractured_json.h: Public API with fractured_json_options struct
- fractured_json-inl.h: Implementation (~1000 lines)
- json_structure_analyzer.h: Structure analysis for layout decisions
- fractured_formatter.h: Formatter class using CRTP pattern

Usage:
  dom::parser parser;
  element doc = parser.parse(json_string);
  std::cout << fractured_json(doc) << std::endl;

  // Or with custom options:
  fractured_json_options opts;
  opts.indent_spaces = 2;
  std::cout << fractured_json(doc, opts) << std::endl;

  // Or format any JSON string (useful with reflection API):
  auto formatted = fractured_json_string(minified_json);

Resolves #2576

* Add comprehensive tests for FracturedJson formatter

Adds 27 test cases covering all aspects of the FracturedJson formatter:

Core functionality tests (13):
- Roundtrip parsing verification
- Inline formatting for simple arrays and objects
- Expanded formatting for complex nested structures
- Compact multiline arrays with configurable items per line
- Table formatting for uniform arrays of objects
- Empty container handling
- All scalar types (string, int, uint, double, bool, null)
- String escaping (quotes, backslashes, control characters)
- Custom indentation options
- Deep nesting (10+ levels)
- Mixed type arrays

Edge case tests (11):
- Unicode strings (Chinese, emoji, Arabic, Russian, accented chars)
- Boundary numbers (INT64_MIN/MAX, UINT64_MAX, DBL_MIN/MAX)
- Nested arrays (arrays of arrays)
- Empty string values
- Keys with special characters (spaces, quotes, colons, etc.)
- Non-uniform arrays (should not trigger table mode)
- Very long strings (500+ chars)
- Large arrays (100 elements)
- Reflection API workflow simulation
- Control characters (tab, newline, CR, null)
- Single element containers

Option tests (3):
- Disable compact multiline mode
- Disable table format mode
- Disable all padding options

* Add FracturedJson integration with builder/reflection API

Extends FracturedJson to work seamlessly with the builder API, enabling
formatted output directly from C++ structs using static reflection.

New functions:
- to_fractured_json_string(obj, opts) - serialize struct to formatted JSON
- to_fractured_json(obj, output, opts) - same with output parameter
- extract_fractured_json<fields...>(obj, opts) - format only specific fields

These functions combine the builder's reflection-based serialization with
FracturedJson formatting in a single convenient call:

  struct User { int id; std::string name; bool active; };
  User user{1, "Alice", true};

  // Minified output (existing):
  auto minified = to_json_string(user);
  // {"id":1,"name":"Alice","active":true}

  // Formatted output (new):
  auto formatted = to_fractured_json_string(user);
  // { "id": 1, "name": "Alice", "active": true }

  // Partial extraction with formatting:
  auto partial = extract_fractured_json<"id", "name">(user);
  // { "id": 1, "name": "Alice" }

New files:
- generic/builder/fractured_json_builder.h - builder integration
- tests/builder/static_reflection_fractured_json_tests.cpp - 7 tests

* Fix INT64_MIN overflow and implement table_similarity_threshold

- Fix undefined behavior when negating INT64_MIN in estimate_number_length()
  and measure_value_length() by returning 20 (the exact length of the
  string representation) directly
- Actually use table_similarity_threshold in check_array_uniformity() by
  calling compute_object_similarity() to compare objects against the first
  object in the array

* Fix -Werror=effc++ member initialization warnings

Initialize all member variables in member initialization lists to
satisfy GCC's -Werror=effc++ flag:
- element_metrics::common_keys - add {} default initializer
- structure_analyzer - add default constructor with member init list
- fractured_formatter - add column_widths_{} to constructor
- fractured_string_builder - add analyzer_{} to constructor

* Add Rule of Five to structure_analyzer class

The class has a pointer member (current_opts_) which triggers
-Werror=effc++ requiring explicit copy/move operations. Delete
copy operations (class shouldn't be copied due to cache) and
default move operations.

* Fix Windows build: wrap std::max to avoid macro conflict

Windows.h defines max/min macros that interfere with std::max/std::min.
Wrapping in parentheses as (std::max)(...) prevents macro expansion.

* Fix GCC 15 false positive -Wfree-nonheap-object warning

GCC 15 on MINGW64 gives a false positive warning in parser_moving_parser()
when the std::vector<std::string> goes out of scope. Suppress this
specific warning with a pragma for GCC builds.

* Fix metrics cache key bug by passing metrics through recursion

The cache was using element addresses as keys, but dom::element objects
are lightweight wrappers that get copied during iteration, causing
different addresses between analysis and formatting phases. This resulted
in cache misses and fallback to empty metrics.

Solution: Store child metrics in the element_metrics struct and pass
them through recursive calls, eliminating the need for address-based
caching entirely.

Changes:
- Add children vector to element_metrics for hierarchical metrics
- Remove metrics_cache_ and related get_metrics/has_metrics methods
- Update all format functions to accept and pass child metrics
- Add public analyze_array/analyze_object overloads for standalone use

* Add ignore patterns for Node.js, Rust, and generated files

Add entries for node_modules, package-lock.json, Rust target
directories, local ablation artifacts, and generated documentation
files.

* Refactor: extract analyze_scalar helper to reduce code duplication

Extract common scalar type handling (STRING, INT64, UINT64, DOUBLE,
BOOL, NULL_VALUE) into a dedicated analyze_scalar method. Each scalar
type shares the same initialization pattern for complexity, child_count,
can_inline, and recommended_layout.

Also simplify boolean formatting in format_scalar to use ternary operator.

* Fix formatting and duplicate error message in amalgamate.py

Reformat cramped is_amalgamator condition to multi-line for readability.
Fix duplicate error message text in _included_filename_root and use
correct variable name (relative_root instead of root).

* Refactor: add count_newlines helper in fractured_json tests

Extract repeated newline counting loop into a reusable static helper
function, used by inline_array_test, inline_object_test, and
expanded_test.

* Revert "Add ignore patterns for Node.js, Rust, and generated files"

This reverts commit 4760ea7cd0.

* various minor changes

---------

Co-authored-by: Daniel Lemire <daniel@lemire.me>
2026-01-20 10:32:24 -05:00

237 lines
6.2 KiB
C++

#include "simdjson.h"
#include "test_builder.h"
#include <string>
#include <string_view>
#include <vector>
using namespace simdjson;
// Test structures for FracturedJson builder integration
struct SimpleUser {
int id;
std::string name;
bool active;
};
struct UserWithEmail {
int id;
std::string name;
std::string email;
bool active;
};
struct NestedData {
std::string title;
std::vector<SimpleUser> users;
int count;
};
struct TableTestData {
std::vector<SimpleUser> records;
};
namespace fractured_json_builder_tests {
// Test basic to_fractured_json_string functionality
bool basic_fractured_json_test() {
TEST_START();
#if SIMDJSON_STATIC_REFLECTION
SimpleUser user{1, "Alice", true};
std::string formatted;
ASSERT_SUCCESS(simdjson::to_fractured_json_string(user).get(formatted));
// Verify it produces valid JSON by re-parsing
simdjson::dom::parser parser;
simdjson::dom::element doc;
ASSERT_SUCCESS(parser.parse(formatted).get(doc));
// Verify values are preserved
int64_t id;
ASSERT_SUCCESS(doc["id"].get_int64().get(id));
ASSERT_EQUAL(id, 1);
std::string_view name;
ASSERT_SUCCESS(doc["name"].get_string().get(name));
ASSERT_EQUAL(name, "Alice");
bool active;
ASSERT_SUCCESS(doc["active"].get_bool().get(active));
ASSERT_EQUAL(active, true);
// Output should be inline since it's simple
std::cout << "Basic FracturedJson output: " << formatted << std::endl;
#endif
TEST_SUCCEED();
}
// Test with custom formatting options
bool custom_options_test() {
TEST_START();
#if SIMDJSON_STATIC_REFLECTION
NestedData data{"Test", {{1, "Alice", true}, {2, "Bob", false}}, 2};
fractured_json_options opts;
opts.indent_spaces = 2;
opts.simple_bracket_padding = false;
std::string formatted;
ASSERT_SUCCESS(simdjson::to_fractured_json_string(data, opts).get(formatted));
// Verify it produces valid JSON
simdjson::dom::parser parser;
simdjson::dom::element doc;
ASSERT_SUCCESS(parser.parse(formatted).get(doc));
std::cout << "Custom options output:\n" << formatted << std::endl;
#endif
TEST_SUCCEED();
}
// Test to_fractured_json with output parameter
bool output_param_test() {
TEST_START();
#if SIMDJSON_STATIC_REFLECTION
SimpleUser user{42, "Charlie", false};
std::string output;
ASSERT_SUCCESS(simdjson::to_fractured_json_string(user).get(output));
// Verify it produces valid JSON
simdjson::dom::parser parser;
simdjson::dom::element doc;
ASSERT_SUCCESS(parser.parse(output).get(doc));
std::cout << "Output param result: " << output << std::endl;
#endif
TEST_SUCCEED();
}
// Test extract_fractured_json for partial serialization
bool extract_fields_test() {
TEST_START();
#if SIMDJSON_STATIC_REFLECTION
UserWithEmail user{1, "Alice", "alice@example.com", true};
// Extract only id and name fields
std::string formatted;
ASSERT_SUCCESS(simdjson::extract_fractured_json<"id", "name">(user).get(formatted));
// Verify it produces valid JSON
simdjson::dom::parser parser;
simdjson::dom::element doc;
ASSERT_SUCCESS(parser.parse(formatted).get(doc));
// Should have id and name but NOT email and active
int64_t id;
ASSERT_SUCCESS(doc["id"].get_int64().get(id));
ASSERT_EQUAL(id, 1);
std::string_view name;
ASSERT_SUCCESS(doc["name"].get_string().get(name));
ASSERT_EQUAL(name, "Alice");
// email should not be present
simdjson::dom::element email_elem;
auto err = doc["email"].get(email_elem);
ASSERT_TRUE(err != SUCCESS); // Should fail - field not present
std::cout << "Extract fields output: " << formatted << std::endl;
#endif
TEST_SUCCEED();
}
// Test table formatting with array of similar objects
bool table_format_test() {
TEST_START();
#if SIMDJSON_STATIC_REFLECTION
TableTestData data{
{{1, "Alice", true}, {2, "Bob", false}, {3, "Carol", true}, {4, "Dave", false}}
};
fractured_json_options opts;
opts.enable_table_format = true;
opts.min_table_rows = 3;
std::string formatted;
ASSERT_SUCCESS(simdjson::to_fractured_json_string(data, opts).get(formatted));
// Verify it produces valid JSON
simdjson::dom::parser parser;
simdjson::dom::element doc;
ASSERT_SUCCESS(parser.parse(formatted).get(doc));
std::cout << "Table format output:\n" << formatted << std::endl;
#endif
TEST_SUCCEED();
}
// Test roundtrip: serialize with reflection, parse back
bool roundtrip_test() {
TEST_START();
#if SIMDJSON_STATIC_REFLECTION
SimpleUser original{123, "TestUser", true};
// Serialize with FracturedJson
std::string formatted;
ASSERT_SUCCESS(simdjson::to_fractured_json_string(original).get(formatted));
// Parse back using ondemand
simdjson::ondemand::parser parser;
simdjson::ondemand::document doc;
ASSERT_SUCCESS(parser.iterate(simdjson::pad(formatted)).get(doc));
// Deserialize back to struct
SimpleUser parsed;
ASSERT_SUCCESS(doc.get<SimpleUser>().get(parsed));
// Verify values match
ASSERT_EQUAL(parsed.id, original.id);
ASSERT_EQUAL(parsed.name, original.name);
ASSERT_EQUAL(parsed.active, original.active);
std::cout << "Roundtrip test passed with: " << formatted << std::endl;
#endif
TEST_SUCCEED();
}
// Test global namespace functions
bool global_namespace_test() {
TEST_START();
#if SIMDJSON_STATIC_REFLECTION
SimpleUser user{99, "GlobalTest", false};
// Test global to_fractured_json_string
std::string formatted;
ASSERT_SUCCESS(simdjson::to_fractured_json_string(user).get(formatted));
// Verify output
simdjson::dom::parser parser;
simdjson::dom::element doc;
ASSERT_SUCCESS(parser.parse(simdjson::pad(formatted)).get(doc));
std::cout << "Global namespace output: " << formatted << std::endl;
#endif
TEST_SUCCEED();
}
bool run() {
return basic_fractured_json_test() &&
custom_options_test() &&
output_param_test() &&
extract_fields_test() &&
table_format_test() &&
roundtrip_test() &&
global_namespace_test();
}
} // namespace fractured_json_builder_tests
int main(int argc, char *argv[]) {
std::cout << "Running FracturedJson builder integration tests..." << std::endl;
#if SIMDJSON_STATIC_REFLECTION
std::cout << "Static reflection is ENABLED" << std::endl;
#else
std::cout << "Static reflection is DISABLED - tests will be skipped" << std::endl;
#endif
return test_main(argc, argv, fractured_json_builder_tests::run);
}