Dependency Injection¶

Stable ID: pattern.dependency-injection
Kind: design-pattern
Status: stable
Source: skill/references/design-patterns/dependency-injection.md

Purpose¶

Supply collaborators explicitly at construction or call boundaries so lifecycle and substitution remain visible.

Use when¶

• A component has infrastructure collaborators or multiple implementations.
• Tests need deterministic substitutes without global mutation.

Avoid when¶

• A service locator or container would hide ownership.
• Simple pure functions have no collaborators to inject.

Applicability¶

• Languages: any, python, q-kdbplus, cpp, rust, dart-flutter, typescript
• Related entries: component.configuration