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common-architecture-decisions

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Index of Architecture Decision Records (ADRs) for cross-cutting technical decisions. Use when making design choices, reviewing proposals for consistency with prior decisions, or onboarding to understand why specific tools or patterns were chosen. Covers test tooling, SDK architecture, code quality, and acceptance test infrastructure.

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Architecture Decision Records

This skill provides an index of ADRs that document cross-cutting technical decisions in the Envilder project. Load this skill to understand the rationale behind tooling choices and architectural patterns before proposing changes.

When to Use

  • Before proposing a new library or tool (check if there's an existing decision)
  • When reviewing code that seems inconsistent with project conventions
  • When adding a new SDK and need to follow established patterns
  • When onboarding and need to understand "why" behind technical choices
  • Before writing tests: check ADR-0002 for the correct tooling per stack

ADR Index

ADRTitleScopeKey Decision
ADR-0001SDK Acceptance Test InfrastructureAll SDKsTestContainers + LocalStack + Lowkey Vault; container wrappers with explicit lifecycle; envilder.json as single source for test tokens
ADR-0002Test Tooling per StackAll stacksVitest (TS), xUnit+NSubstitute+AwesomeAssertions (NET), pytest+unittest.mock (Py)
ADR-0003SDK Architecture PatternAll SDKsThree-layer (Domain→App→Infra), no DI framework, facade as primary API, internal factory
ADR-0004Code Quality and FormattingAll stacksBiome (TS), dotnet format (.NET), black+isort (Py); Secretlint for credentials
ADR-0005SDK Integration TiersAll SDKsThree tiers (Facade, Builder, Framework); Tier 3 separate package; .NET exception; community-driven
ADR-0006Monorepo StructureAll componentsSingle repo, independent releases per component via version-bump detection, no orchestrator
ADR-0007Trunk-Based DevelopmentAll componentsSingle main branch, short-lived feature branches, squash merge, feature flags for incomplete work
ADR-0008Map-File Schema SpecificationAll componentsJSON Schema v1, $ prefix reserved, $config strict fields, file provider for testing (planned), EnvilderOptions.FromFile (planned)
ADR-0009SDK Dependency Compatibility PolicyAll SDKsMinimum viable engine + dep versions in published SDKs; devDeps unconstrained; acceptance tests verify minimum

Quick Reference: Test Doubles per Stack

StackMock/SpyStubFake (data)Dummy
TypeScriptvi.fn() / vi.mock()vi.fn().mockResolvedValue()inlineinline
.NETNSubstitute (Received())NSubstitute (.Returns())Bogus (Mother pattern)AutoFixture
Pythonunittest.mock.Mock / AsyncMockMock(return_value=...)inline / fixturesinline

Quick Reference: Container Testing

StackPackageAWSAzure
TypeScripttestcontainers@testcontainers/localstackCustom (Lowkey Vault)
.NETTestcontainersTestcontainers.LocalStackCustom (Lowkey Vault)
Pythontestcontainerstestcontainers[localstack]Custom (Lowkey Vault)

Rules

  1. Before adding a new testing tool: Check ADR-0002. If not listed, propose an ADR amendment or new ADR.
  2. Before changing SDK public API surface: Check ADR-0003. All SDKs must follow the same facade/builder/client pattern.
  3. Before changing formatters or linters: Check ADR-0004. Changes affect CI and all contributors.
  4. Before changing acceptance test infrastructure: Check ADR-0001. Container wrappers, token resolution, and CI patterns are standardized.

Creating a New ADR

Use the format in docs/adr/:

# ADR-NNNN: Title

## Status
Proposed | Accepted | Deprecated | Superseded by ADR-XXXX

## Context
Why this decision is needed.

## Decision
What we chose and the details.

## Consequences
### Positive
### Negative

## When to Reconsider

Number sequentially. Keep scope focused: one decision per ADR.

prefix reserved, `$config` strict fields, `file` provider for testing (planned), `EnvilderOptions.FromFile` (planned) |\n| [ADR-0009](../../../docs/adr/0009-sdk-dependency-compatibility-policy.md) | SDK Dependency Compatibility Policy | All SDKs | Minimum viable engine + dep versions in published SDKs; devDeps unconstrained; acceptance tests verify minimum |\n\n## Quick Reference: Test Doubles per Stack\n\n| Stack | Mock/Spy | Stub | Fake (data) | Dummy |\n| ----- | -------- | ---- | ----------- | ----- |\n| TypeScript | `vi.fn()` / `vi.mock()` | `vi.fn().mockResolvedValue()` | inline | inline |\n| .NET | NSubstitute (`Received()`) | NSubstitute (`.Returns()`) | Bogus (Mother pattern) | AutoFixture |\n| Python | `unittest.mock.Mock` / `AsyncMock` | `Mock(return_value=...)` | inline / fixtures | inline |\n\n## Quick Reference: Container Testing\n\n| Stack | Package | AWS | Azure |\n| ----- | ------- | --- | ----- |\n| TypeScript | `testcontainers` | `@testcontainers/localstack` | Custom (Lowkey Vault) |\n| .NET | `Testcontainers` | `Testcontainers.LocalStack` | Custom (Lowkey Vault) |\n| Python | `testcontainers` | `testcontainers[localstack]` | Custom (Lowkey Vault) |\n\n## Rules\n\n1. **Before adding a new testing tool**: Check ADR-0002. If not listed, propose\n an ADR amendment or new ADR.\n2. **Before changing SDK public API surface**: Check ADR-0003. All SDKs must\n follow the same facade/builder/client pattern.\n3. **Before changing formatters or linters**: Check ADR-0004. Changes affect CI\n and all contributors.\n4. **Before changing acceptance test infrastructure**: Check ADR-0001. Container\n wrappers, token resolution, and CI patterns are standardized.\n\n## Creating a New ADR\n\nUse the format in `docs/adr/`:\n\n```markdown\n# ADR-NNNN: Title\n\n## Status\nProposed | Accepted | Deprecated | Superseded by ADR-XXXX\n\n## Context\nWhy this decision is needed.\n\n## Decision\nWhat we chose and the details.\n\n## Consequences\n### Positive\n### Negative\n\n## When to Reconsider\n```\n\nNumber sequentially. Keep scope focused: one decision per ADR.\n"}],"versionEndpoint":"/skill/api/version"}