Scopes.getReadableSource() should output annotation values.

In Square Register, we use a single scope annotation for most scopes and rely on annotation equality that Dagger implements correctly. Our annotation is @SingleIn:

/**
 * A class annotated with SingleIn(foo) is a singleton scoped to (ie, held by) the
 * {@link dagger.Component} that is also annotated with SingleIn(foo).
 */
@Scope public @interface SingleIn {
  Class<?> value();
}

Usage example: @SingleIn(LoggedInScope.class)

This has two advantages:

• No need to create new annotations for every scope (we have a lot of scope)
• We can command + click the class, which is usually an outer class of where the component is defined, so that provides easy navigation.

This works great. Unfortunately, Dagger error messages do not output the annotation values:

/src/main/java/com/squareup/FooComponent.java:18: error: com.squareup.FooComponent scoped with @com.squareup.dagger.SingleIn may not reference bindings with different scopes:
@Component(
^
      @com.squareup.dagger.SingleIn class com.squareup.bar.Bar
1 error

Ideally this would be:

/src/main/java/com/squareup/FooComponent.java:18: error: com.squareup.FooComponent scoped with @com.squareup.dagger.SingleIn(com.squareup.AppScope.class) may not reference bindings with different scopes:
@Component(
^
      @com.squareup.dagger.SingleIn(com.squareup.LoggedInScope.class) class com.squareup.bar.Bar
1 error

Scopes.getReadableSource() is currently implemented like so:

  /**
   * Returns the readable source representation (name with @ prefix) of the scope's annotation type.
   *
   * <p>It's readable source because it has had common package prefixes removed, e.g.
   * {@code @javax.inject.Singleton} is returned as {@code @Singleton}.
   *
   * <p>Does not return any annotation values, since {@link javax.inject.Scope @Scope} annotations
   * are not supposed to have any.
   */
  static String getReadableSource(Scope scope) {
    return stripCommonTypePrefixes("@" + scope.scopeAnnotationElement().getQualifiedName());
  }

While the Javax scope annotation javadoc states it should not have attributes, Dagger doesn’t enforce that and it gives us much more flexibility.

[JakeWharton]

s/at Square/in Square Register/

On Mon, Apr 30, 2018, 8:24 PM Pierre-Yves Ricau [e-mail] wrote:

At Square, we use a single scope annotation for most scopes and rely on annotation equality that Dagger implements correctly. Our annotation is @SingleIn:

/**

• A class annotated with SingleIn(foo) is a singleton scoped to (ie, held by) the
• {@link dagger.Component} that is also annotated with SingleIn(foo). */ @Scope public @interface SingleIn { Class<?> value(); }

Usage example: @SingleIn(LoggedInScope.class)

This has two advantages:

• No need to create new annotations for every scope (we have a lot of scope)
• We can command + click the class, which is usually an outer class of where the component is defined, so that provides easy navigation.

This works great. Unfortunately, Dagger error messages do not output the annotation values:

/src/main/java/com/squareup/FooComponent.java:18: error: com.squareup.FooComponent scoped with @com.squareup.dagger.SingleIn may not reference bindings with different scopes: @Component( ^ @com.squareup.dagger.SingleIn class com.squareup.bar.Bar 1 error

Ideally this would be:

/src/main/java/com/squareup/FooComponent.java:18: error: com.squareup.FooComponent scoped with @com.squareup.dagger.SingleIn(com.squareup.AppScope.class) may not reference bindings with different scopes: @Component( ^ @com.squareup.dagger.SingleIn(com.squareup.LoggedInScope.class) class com.squareup.bar.Bar 1 error

Scopes.getReadableSource() https://github.com/google/dagger/blob/master/java/dagger/internal/codegen/Scopes.java#L75 is currently implemented like so:

/**

• Returns the readable source representation (name with @ prefix) of the scope’s annotation type.

• It's readable source because it has had common package prefixes removed, e.g.

• {@code @javax.inject.Singleton} is returned as {@code @Singleton}.

• Does not return any annotation values, since {@link javax.inject.Scope @Scope} annotations

• are not supposed to have any. */ static String getReadableSource(Scope scope) { return stripCommonTypePrefixes(“@” + scope.scopeAnnotationElement().getQualifiedName()); }

While the Javax scope annotation javadoc states it should not have attributes., Dagger doesn’t enforce that and it gives us much more flexibility.

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[pyricau]

💃