feat: Add EditDependency to upsert SDK dependency versions

[rshade]

Summary

Implemented the EditDependency() option function (Issue #40) that allows upserts of dependencies for the program under test to specific versions. The feature automatically detects the language/build system and modifies the appropriate dependency files.

Supported Languages:

• Node.js (package.json via npm/yarn)
• Python (requirements.txt via pip)
• Go (go.mod via go get)
• .NET/C# (.csproj files via NuGet)
• YAML (requires manual configuration)

Implementation Details

New Files

• pulumitest/opttest/editdependency.go - Option function and DependencyEdit type
• pulumitest/editdependency.go - Language detection and editing logic for all supported languages
• pulumitest/editdependency_test.go - Comprehensive unit tests for all language implementations

Modified Files

• pulumitest/opttest/opttest.go - Added DependencyEdits field to Options struct
• pulumitest/newStack.go - Added execution logic and warning when used with LocalProviderPath
• README.md - Added documentation and usage examples
• CLAUDE.md - Added feature documentation and implementation details

Key Features

• Automatic Language Detection: Detects Go, Node.js, Python, .NET, and YAML based on file presence
• Version Specification: Sets exact version for packages in appropriate format per language
• Conflict Warning: Logs warning when EditDependency is used with LocalProviderPath
• Error Handling: Provides clear error messages when dependency files are not found or editing fails
• Consistent API: Follows existing Options pattern like YarnLink and GoModReplacement

Test Coverage

• 15 unit tests covering:
  • Language detection for all supported languages
  • Editing existing dependencies
  • Adding new dependencies
  • Various dependency file formats (package.json, requirements.txt, .csproj)
  • Error cases (missing files, invalid inputs)

Code Quality

• Passes golangci-lint v1.64.8 with zero new issues
• All code follows existing patterns and conventions
• Proper error handling with descriptive messages
• Usage of strings.EqualFold for case-insensitive string comparison

Testing

Run tests with:

go test ./pulumitest -v

Run linting with:

~/.local/bin/golangci-lint-versions/golangci-lint run ./...

Usage Example

import (
  "filepath"
  "github.com/pulumi/providertest/pulumitest"
  "github.com/pulumi/providertest/pulumitest/opttest"
)

func TestWithSpecificSDKVersion(t *testing.T) {
  test := pulumitest.NewPulumiTest(t,
    filepath.Join("path", "to", "program"),
    opttest.EditDependency("pulumi", "3.50.0"))
  test.Preview(t)
  test.Up(t)
}

Backward Compatibility

Fully backward compatible. The EditDependency feature is optional and doesn't affect existing code.

Fixes #40