chore: import upstream snapshot with attribution

cli-tool/components/commands/testing/testing_plan_integration.md

@@ -0,0 +1,37 @@
+---
+allowed-tools: Read, Write, Edit, Bash
+argument-hint: [target-code] | [test-type] | --rust | --inline | --refactoring-suggestions
+description: Create comprehensive integration testing plan with inline tests and refactoring recommendations
+---
+
+# Testing Plan Integration
+
+Create integration testing plan with inline test strategy and refactoring suggestions: **$ARGUMENTS**
+
+## Current Testing Context
+
+- Project type: !`[ -f Cargo.toml ] && echo "Rust project" || [ -f package.json ] && echo "Node.js project" || echo "Multi-language project"`
+- Test framework: !`find . -name "*.test.*" -o -name "*.spec.*" | head -3` existing tests
+- Target code: Analysis of $ARGUMENTS for testability assessment
+- Integration complexity: Assessment of component interactions and dependencies
+
+## Task
+
+Execute comprehensive integration testing plan with testability analysis:
+
+**Planning Focus**: Use $ARGUMENTS to specify target code, test type requirements, Rust inline testing, or refactoring suggestions
+
+**Integration Testing Framework**:
+
+1. **Code Testability Analysis** - Analyze target code structure, identify testing challenges, assess coupling levels, evaluate dependency injection
+2. **Test Strategy Design** - Design integration test approach, plan inline vs separate test files, identify test boundaries, optimize test isolation
+3. **Refactoring Assessment** - Identify testability improvements, suggest dependency injection, recommend interface abstractions, optimize component boundaries
+4. **Test Case Planning** - Design integration scenarios, identify critical paths, plan data flow testing, assess error handling coverage
+5. **Mock Strategy** - Plan external dependency mocking, design test doubles, identify integration boundaries, optimize test performance
+6. **Execution Planning** - Design test execution order, plan test data management, optimize test environment setup, ensure test isolation
+
+**Advanced Features**: Rust-style inline testing, property-based integration tests, contract testing, service virtualization, chaos engineering integration.
+
+**Quality Assurance**: Test maintainability, execution performance, coverage optimization, feedback loop efficiency.
+
+**Output**: Comprehensive integration test plan with test case specifications, refactoring recommendations, implementation strategy, and quality metrics.