Dependency Injection

Purpose

Make dependencies explicit and replaceable without adding unnecessary framework weight.

When to use

• Adding Hilt or Koin.
• Injecting ViewModels, repositories or data sources.
• Fixing scope or binding problems.
• Replacing dependencies in tests.

Inputs to inspect

• Existing DI framework or manual DI.
• Object lifetimes and scopes.
• ViewModel and repository constructors.
• Test replacement needs.

Required workflow

1. Detect current DI pattern.
2. Add the smallest binding/module needed.
3. Use scopes intentionally.
4. Wire ViewModel and repository dependencies.
5. Add test fakes or replacement modules.

Rules

• Do not mix Hilt and Koin without strong reason.
• Avoid hidden service locators.
• Do not inject Context unless needed.
• Keep singletons immutable or thread-safe.
• Do not break Compose previews.

Related existing skills

Local skills to invoke

• android-architecture
• kotlin-core
• testing
• room-datastore

External companion skills to use when installed

Do not assume these companion skills are installed. Prefer the local skills above first, then consult [Companion Skills](../../docs/COMPANION_SKILLS.md) for install and verification commands.

• android/skills — use for official Android workflow alignment when a first-party companion skill exists for the task.

Files commonly touched

• di modules
• Application class
• ViewModels
• repositories
• test modules

Commands to validate

./gradlew test
./gradlew assembleDebug
./gradlew lint

Common mistakes to avoid

• Injecting everything by default.
• Creating circular dependencies.
• Using singletons for mutable state.
• Forgetting test replacements.

Checklist

• Bindings minimal.
• Scopes correct.
• Tests can replace dependencies.
• Previews still work.
• Build passes.

Example prompts

• Use $super-android-kotlin-firebase to add Hilt for repositories and ViewModels.
• Use $super-android-kotlin-firebase to fix this DI binding error.

Expected response style

Respond with: brief diagnosis, change plan, affected files, code or diff summary, validation commands, tests added or recommended, risks, and next step. For review tasks, lead with findings ordered by severity.

References

• ../../docs/audits/FUENTES_LOCALES.md
• references/di-scopes-and-tests.md
• templates/hilt-module-template.md

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: GDvega
• Source: GDvega/super-android-kotlin-firebase-skill
• License: MIT

Install and usage instructions live in the source repository linked above.