R17BREAKINGfunction

Static Changed

Flags when a method changes between static and instance (or vice versa). All call sites need to change syntax.

Applies to

TypeScriptJava

Why it matters

Static methods are called on the class (MyClass.create()), while instance methods require an object (obj.create()). Changing between the two invalidates all call sites.

Example

Before (static)

// factory.ts
export class UserFactory {
  static create(name: string): User {
    return new User(name);
  }
}

// caller
const user = UserFactory.create("Alice");

After (instance method)

// factory.ts (BREAKING)
export class UserFactory {
  create(name: string): User {
    return new User(name);
  }
}

// caller — NOW BROKEN
const user = UserFactory.create("Alice"); // ERROR: not a static method

What you see in the terminal

$ npx dg check

  [BREAKING] create (signature_change)
  src/factory.ts:3
  Method changed from static to instance. Call site syntax must change.

How detection works

The classifier compares the isStatic flag on both signatures.

Real-world scenario

A factory pattern is refactored from static methods to instance methods for dependency injection. All callers using the static syntax will break.

Edge cases

Only relevant in class-based languages (TypeScript, Java)
In Go, this is the difference between a function and a method with a receiver

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