Scan Effect Solutions

Effect Solutions Compliance Audit

Audit a repository against Effect TypeScript best practices from effect.solutions. Follow this skill to produce a consistent, evidence-based compliance report.

Prerequisites

Load current effect.solutions recommendations:

effect-solutions list

Load guidance used by this checklist:

effect-solutions show tsconfig
effect-solutions show services-and-layers
effect-solutions show data-modeling
effect-solutions show error-handling
effect-solutions show config
effect-solutions show testing

Load the effect-ts skill for Effect-specific implementation patterns:

skill({ name: "effect-ts" })

Audit Checklist

1. TypeScript Configuration

Inspect tsconfig.base.json (or tsconfig.json) and verify:

• exactOptionalPropertyTypes: true
• strict: true
• noUnusedLocals: true
• declarationMap: true
• sourceMap: true
• Confirm Effect Language Service plugin is configured.
• Confirm module setting matches project type (preserve/bundler for apps, NodeNext for libraries).

Reference: effect-solutions show tsconfig

2. Services & Layers Pattern

Search for Effect services and verify:

• Confirm services are defined with Context.Tag.
• Confirm tag identifiers follow @path/ServiceName pattern.
• Confirm layers use Layer.effect or Layer.sync.
• Confirm a single Effect.provide is applied at the entry point.

Reference: effect-solutions show services-and-layers

3. Data Modeling

Inspect data modeling and verify:

• Confirm Schema.Class is used for records.
• Confirm Schema.TaggedClass is used for variants.
• Confirm branded types are used for primitives (IDs, emails, and similar values).
• Confirm pattern matching uses Match.valueTags.

Reference: effect-solutions show data-modeling

4. Error Handling

Inspect error handling and verify:

• Confirm Schema.TaggedError is used for domain errors.
• Confirm error recovery uses catchTag/catchTags where appropriate.
• Confirm defects and typed errors are separated intentionally.

Reference: effect-solutions show error-handling

5. Configuration

Inspect configuration patterns and verify:

• Confirm Schema.Config is used for validation.
• Confirm a config service layer pattern is present.
• Confirm secrets use Config.redacted.

Reference: effect-solutions show config

6. Testing

Inspect tests and verify:

• Confirm tests use @effect/vitest.
• Confirm Effect tests use it.effect().
• Confirm test layer composition follows Effect layer patterns.

Reference: effect-solutions show testing

7. Runtime Execution Anti-Pattern (Effect.runPromise / Effect.runSync in Application Code)

Search application code for direct Effect.runPromise and Effect.runSync usage. Exclude test-only files and test helpers (__tests__/, *.test.ts, *.spec.ts, fixture directories).

Treat bare Effect.runPromise / Effect.runSync as findings when they bypass the project runtime composition. Bare execution typically uses the default runtime without project-provided layers (for tracing, config, logging, or domain services).

Apply project-aware evaluation:

• Prefer the project's runtime entrypoint (for example runtime.runPromise) in application code.
• Accept explicit layer provisioning when runtime usage is not feasible (for example during bootstrap or dependency-cycle constraints).
• Exempt tests that intentionally provide dedicated test layers.

Template-ts convention example (use only when applicable in the audited repo):

• ManagedRuntime in effect-runtime.ts
• AppLayer composition
• SentryTracingLive in runtime-provided observability

Search patterns:

• Effect.runPromise( under application source directories (for example src/, apps/*/src/, packages/*/src/)
• Effect.runSync( under application source directories (same scope)

Report each occurrence with:

• File path and line
• Whether it's using runtime.runPromise (✅) or bare Effect.runPromise (❌)
• Whether required observability/config layers are provided by runtime or explicit Effect.provide fallback

Reference: effect-solutions show services-and-layers

8. Option/Either Internal Tag Anti-Patterns

Inspect direct _tag branching on Option/Either in application code and tests.

• Production code: report all direct _tag usage as findings with replacement recommendation
• Tests: allow _tag assertions for domain error identity, but flag control-flow branching patterns that should use helpers
• Prefer:
  • Either.match, Either.isLeft, Either.isRight
  • Option.match, Option.isSome, Option.isNone, Option.getOrElse

Search patterns to include:

• if (.*\._tag === "Left")
• if (.*\._tag === "Right")
• if (.*\._tag === "Some")
• if (.*\._tag === "None")
• expect\(.*\._tag\)

Reference: effect-solutions show error-handling

Output Format

Provide a structured report with:

1. Summary: Overall compliance score using the rubric below.

   Scoring rubric (0-16 total):

   • Evaluate each checklist section (1-8) on a 0-2 scale.
   • 2: Fully compliant or only minor cosmetic gaps.
   • 1: Partially compliant, meaningful gaps present.
   • 0: Non-compliant or pattern missing.
   • Total score = sum of all section scores.
   • Provide percentage = (total / 16) * 100, rounded to whole number.

2. What's Working Well: List patterns that follow best practices

3. Improvements Needed: List specific issues with:

   • File location
   • Current pattern
   • Recommended pattern
   • Priority (high/medium/low)
   • Scope label: production or test

4. Quick Wins: Easy fixes that can be done immediately

5. Next Steps: Recommended order of improvements

Related Skills

• effect-ts — Effect services, layers, error handling, config patterns
• testing-patterns — Vitest and @effect/vitest test patterns
• code-review — General code review methodology (includes Effect section)