Capi Test Fixer

C API Test Fixer Skill

This skill automatically diagnoses and fixes common C API unit test failures in OpenHarmony ACE Engine. It handles patterns like missing static modifiers in test builds, incorrect Converter API usage, and test build configuration issues.

When to Use This Skill

Use this skill when encountering C API unit test failures, particularly:

• Linker errors: undefined symbol: OHOS::Ace::NG::GeneratedModifier::Get*StaticModifier()
• Test failures: modifier_test_base.h:210: Expected: (modifier_) != (nullptr)
• Compilation warnings about pointer/reference mismatches
• Build failures with "undefined reference" for static modifier functions
• Test build configuration issues with missing files

Common Failure Patterns

Pattern 1: Missing Static Modifier in Test Builds

Symptoms:

• Linker error: undefined symbol: OHOS::Ace::NG::GeneratedModifier::Get*StaticModifier()
• Test failure: modifier_test_base.h:210: Expected: (modifier_) != (nullptr)

Root Cause: Modifier function uses DynamicModuleHelper which returns nullptr in tests.

Fix Pattern:

1. Add ARKUI_CAPI_UNITTEST conditional compilation to modifier.cpp
2. Include static modifier implementation in test BUILD.gn

Pattern 2: Incorrect Converter API Usage

Symptoms:

• Test failure comparing nullopt vs nullptr
• Compilation warnings about pointer/reference mismatches

Root Cause: Using Converter::GetOptPtr(&local_var) instead of Converter::GetOpt(local_var)

Fix Pattern: Replace GetOptPtr(&var) with GetOpt(var) for local variables.

Pattern 3: Test Build Configuration Missing Files

Symptoms:

• Build fails with "undefined reference" for static modifier functions
• File not included in test build sources

Root Cause: Static modifier .cpp file not listed in test BUILD.gn sources

Fix Pattern: Add missing .cpp file to test BUILD.gn sources list.

Pattern 4: Callback Invoke vs InvokeSync Mismatch

Symptoms:

• Test callback values remain at initial value (e.g., g_indexValue = 0)
• Event callbacks silently don't fire
• Test error: Expected: g_indexValue == INDEX, Actual: 0 vs 10

Root Cause: Implementation uses CallbackHelper::InvokeSync() but test callbacks are created with Converter::ArkCallback<T>(lambda) where the lambda matches the call signature (Ark_Int32 nodeId, ...args). InvokeSync uses callSync field which is nullptr, so the callback silently does nothing.

The two ArkCallback overloads in reverse_converter.h select based on function signature:

• call type: void (*)(Ark_Int32 resourceId, ...args) → sets .call, .callSync = nullptr
• callSync type: void (*)(Ark_VMContext vmContext, Ark_Int32 resourceId, ...args) → sets .callSync, .call = nullptr

Fix Pattern: Add Ark_VMContext vmContext as the first parameter in test callback lambdas.

// Before (matches call signature → InvokeSync finds callSync=nullptr → no-op)
auto callback = [](Ark_Int32 nodeId, const Ark_Int32 index) {
    g_indexValue = Converter::Convert<int32_t>(index);
};

// After (matches callSync signature → InvokeSync works correctly)
auto callback = [](Ark_VMContext vmContext, Ark_Int32 nodeId, const Ark_Int32 index) {
    g_indexValue = Converter::Convert<int32_t>(index);
};

Common affected tests: Any event callback test (onChange, onSelected, onWillShow, etc.) where the implementation was changed from Invoke() to InvokeSync().

Pattern 5: Ark_String Dangling Pointer in Getters

Symptoms:

• Getter returns garbage/corrupted data (e.g., "\0x\x1D" instead of "xor")
• Use-after-free in string return values
• Only affects getters that return Ark_String

Root Cause: Peer getter returns std::string by value. Converter::ArkValue<Ark_String>() stores chars pointer to the temporary's data. When the temporary is destroyed, the pointer dangles.

In reverse_converter.h, AssignArkValue(Ark_String& dst, const std::string_view& src, ConvContext *ctx):

• When ctx != nullptr: copies data into persistent storage via ctx->Store(src)
• When ctx == nullptr (default): stores raw pointer dst.chars = src.data() — dangles if source is temporary

Fix Pattern: Change peer getter to return const std::string& instead of std::string (since it returns a member variable), so the Ark_String points to stable memory.

// Before (returns by value → Ark_String.chars dangles)
std::string GetGlobalCompositeOperation() const {
    return globalCompositeOperation_;
}

// After (returns by reference → Ark_String.chars points to member)
const std::string& GetGlobalCompositeOperation() const {
    return globalCompositeOperation_;
}

Alternative fix: Use Converter::FC (frame context) to store the string data persistently:

auto result = peerImpl->GetGlobalCompositeOperation();
return Converter::ArkValue<Ark_String>(result, Converter::FC);

Skill Implementation

The skill performs automated diagnosis through:

1. Error Analysis

• Parse build logs (out/rk3568/build.log)
• Extract linker errors and undefined symbols
• Analyze test failure messages

2. Pattern Matching

# Example patterns from error_patterns.json
PATTERNS = {
    "static_modifier_missing": r"undefined symbol.*Get(\w+)StaticModifier",
    "converter_api_misuse": r"GetOptPtr\(&",
    "nullptr_modifier": r"modifier_test_base\.h.*modifier_.*!=.*nullptr",
}

3. Fix Generation

Based on detected patterns:

• Static modifier missing:

  • Check if modifier.cpp has ARKUI_CAPI_UNITTEST conditional
  • Verify test BUILD.gn includes static_modifier.cpp
  • Generate appropriate patches

• Converter API misuse:

  • Locate offending test file
  • Suggest GetOptPtr → GetOpt replacement

• Build configuration:

  • Check test BUILD.gn source lists
  • Add missing static modifier files

Usage Examples

Diagnose and Fix All Issues

claude-code skill capi-test-fixer --diagnose

Fix Specific Test Failure

claude-code skill capi-test-fixer --test SymbolGlyphModifierTest

Analyze Build Log

claude-code skill capi-test-fixer --build-log out/rk3568/build.log

Integration with Existing Skills

This skill complements:

• openharmony-build: Uses build logs for diagnosis
• build-error-analyzer: Focuses specifically on C API test patterns
• tdd: Provides test-specific fixes

File Structure

.claude/skills/capi-test-fixer/
├── SKILL.md                 # This file
├── README.md                # Detailed documentation
├── skill.json               # Skill configuration
├── test_skill.py            # Test script
├── scripts/
│   ├── diagnose.py          # Main diagnosis script
│   ├── fix_static_modifier.py
│   ├── fix_converter_api.py
│   └── fix_build_config.py
├── templates/
│   ├── static_modifier.patch
│   └── converter_fix.patch
└── patterns/
    └── error_patterns.json  # Error pattern definitions

Error Resolution Workflow

1. Collect Data: Build logs, test outputs, source files
2. Pattern Match: Identify failure category using error_patterns.json
3. Root Cause Analysis: Determine exact issue location
4. Fix Generation: Create appropriate patches using templates
5. Validation: Verify fixes work by checking test compilation

Common Fix Templates

Static Modifier Fix

// Before
const GENERATED_ArkUI*Modifier* Get*Modifier()
{
    auto* module = DynamicModuleHelper::GetInstance().GetDynamicModule("*");
    return reinterpret_cast<const GENERATED_ArkUI*Modifier*>(module->GetStaticModifier());
}

// After
#ifdef ARKUI_CAPI_UNITTEST
const GENERATED_ArkUI*Modifier* Get*StaticModifier();
#endif

const GENERATED_ArkUI*Modifier* Get*Modifier()
{
    static const GENERATED_ArkUI*Modifier* cachedModifier = nullptr;
    if (cachedModifier == nullptr) {
#ifdef ARKUI_CAPI_UNITTEST
        cachedModifier = GeneratedModifier::Get*StaticModifier();
#else
        auto* module = DynamicModuleHelper::GetInstance().GetDynamicModule("*");
        CHECK_NULL_RETURN(module, nullptr);
        cachedModifier = reinterpret_cast<const GENERATED_ArkUI*Modifier*>(module->GetStaticModifier());
#endif
    }
    return cachedModifier;
}

Converter API Fix

// Before
auto optValue = Converter::GetOptPtr(&ptr);

// After
auto optValue = Converter::GetOpt(ptr);

BUILD.gn Fix

# Add to test/unittest/capi/BUILD.gn sources
sources += [
    "$ace_root/frameworks/core/components_ng/pattern/*/bridge/*_static_modifier.cpp",
]

Callback InvokeSync Fix

// Before (call signature — InvokeSync ignores this)
auto callback = [](Ark_Int32 nodeId, const Ark_Int32 index) { ... };

// After (callSync signature — InvokeSync uses this)
auto callback = [](Ark_VMContext vmContext, Ark_Int32 nodeId, const Ark_Int32 index) { ... };

// For VoidCallback:
// Before
auto cb = [](const Ark_Int32 resourceId) { ... };
// After
auto cb = [](Ark_VMContext vmContext, const Ark_Int32 resourceId) { ... };

Ark_String Lifetime Fix

// Before (dangling pointer — getter returns std::string by value)
std::string GetValue() const { return member_; }

// After (stable pointer — getter returns const reference)
const std::string& GetValue() const { return member_; }

Best Practices

1. Always check existing patterns: Radio modifier already implements ARKUI_CAPI_UNITTEST pattern
2. Verify test builds: Ensure ARKUI_CAPI_UNITTEST is defined in test config
3. Use proper Converter API: GetOpt for values, GetOptPtr for pointers
4. Maintain consistency: Follow established patterns in codebase
5. Test after fixes: Always rebuild and run tests to verify fixes work

Supported Patterns

The skill supports the following error patterns (defined in patterns/error_patterns.json):

1. static_modifier_missing: Detects undefined symbol errors for static modifiers
2. converter_api_misuse: Detects incorrect GetOptPtr(&var) usage
3. nullptr_modifier_in_tests: Detects modifier returning nullptr in tests
4. test_build_config_missing_files: Detects missing files in BUILD.gn
5. arkui_capi_unittest_compilation_error: Detects ARKUI_CAPI_UNITTEST compilation errors
6. dynamic_module_helper_nullptr: Detects DynamicModuleHelper returning nullptr
7. callback_invoke_vs_invoke_sync: Detects test callbacks using call signature when implementation uses InvokeSync (requires callSync signature)
8. ark_string_dangling_pointer: Detects Ark_String getters returning dangling pointers from temporary std::string

Limitations

• Cannot fix complex test logic errors
• Requires clear error patterns
• May need manual review for edge cases
• Focuses on C API unit test failures only (not other test types)

Contributing

Add new patterns to patterns/error_patterns.json:

{
  "pattern_name": {
    "regex": "error pattern",
    "category": "static_modifier|converter_api|build_config",
    "fix_template": "template_name",
    "severity": "high|medium|low"
  }
}

Update fix templates in the templates/ directory as needed for new patterns.