Top-level contribution providers (#2057)

Co-authored-by: Ralf Wondratschek <[email protected]>

Author: ZacSweers

.github/workflows/benchmark-regression.yml

@@ -558,7 +558,7 @@ jobs:
     # Only run on push to main, after both benchmark jobs complete
     if: github.event_name == 'push'
     needs: [benchmark, build-benchmark]
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-slim
 
     steps:
       - name: Checkout gh-pages

.github/workflows/benchmarks.yml

@@ -89,7 +89,7 @@ jobs:
   # Shared job to validate inputs and build modes string
   validate:
     name: "Validate inputs"
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-slim
     outputs:
       modes: ${{ steps.modes.outputs.modes }}
       is_single_ref: ${{ steps.check_mode.outputs.is_single_ref }}

.github/workflows/check-kotlin-bootstrap.yml

@@ -12,7 +12,7 @@ env:
 
 jobs:
   check-versions:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-slim
     permissions:
       issues: write
 

.github/workflows/ci.yml

@@ -29,7 +29,7 @@ jobs:
 
   generate-matrix:
     name: "⊹ generate compiler matrix ⊹"
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-slim
     outputs:
       matrix: ${{ steps.generate.outputs.matrix }}
     steps:
@@ -211,7 +211,7 @@ jobs:
   # https://jakewharton.com/fan-in-to-a-single-required-github-action/
   final-status:
     if: always()
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-slim
     needs:
       - format
       - core

.github/workflows/ide-integration.yml

@@ -21,7 +21,7 @@ concurrency:
 jobs:
   generate-matrix:
     name: Generate IDE matrix
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-slim
     outputs:
       ide-matrix: ${{ steps.matrix.outputs.ide-matrix }}
     steps:
@@ -134,7 +134,7 @@ jobs:
 
   ide-integration:
     if: always()
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-slim
     needs:
       - ide-tests
     steps:

.github/workflows/update-ide-mappings.yml

@@ -12,7 +12,7 @@ permissions:
 
 jobs:
   update-mappings:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-slim
     timeout-minutes: 15
     steps:
       - uses: actions/checkout@v6

CHANGELOG.md

@@ -6,6 +6,30 @@ Changelog
 
 ### New
 
+#### `generateContributionProviders`
+
+This release introduces a new `generateContributionProviders` API (Kotlin 2.3.20+) to optimize behavior with contributed APIs.
+
+Up to now, Metro's aggregation APIs (i.e. `@Contributes*` binding annotations) have worked similar to Anvil, where the ultimately just generate `@Binds` declarations as simple shorthands for the consuming graphs. This comes with the caveat that the injected class _must_ be publicly visible if it's used outside of that module.
+
+Now, if you enable the new `generateContributionProviders` feature, Metro will instead generate top-level `@Provides` declarations that mirror the injected class's inputs but only return its _bound type_. This means the annotated class can remain `internal`, which both helps encapsulation and incremental compilation.
+
+```
+interface Base
+
+@ContributesBinding(AppScope::class)
+@Inject
+internal class Impl : Base
+
+// Works across modules!
+@DependencyGraph(AppScope::class)
+interface AppGraph {
+  val base: Base
+}
+```
+
+The tradeoff is that `Impl` is no longer available directly on the graph. If you had any explicit code usages of `Impl`, you would have to remove those too in favor of purely the bound type.
+
 #### [**[MEEP-1776]**](https://github.com/ZacSweers/metro/discussions/1776) `@DefaultBinding`
 
 This release introduces a new `@DefaultBinding` annotation that allows for setting a default binding on _supertypes_ of contributed classes. This is useful for common base classes with generics that would otherwise require repetitive (or error-prone) explicit `binding<T>()` declarations in subtypes.
@@ -19,6 +43,10 @@ interface BaseFactory<T : BaseFactory<T>>
 class HomeFactory(...) : BaseFactory<HomeFactory>
 ```
 
+### Fixes
+
+- **[IR]** Consider Anvil's `rank` parameter when processing contributed binding containers.
+
 ### Changes
 
 - Removed `@Assisted.value`. See the [docs](https://zacsweers.github.io/metro/latest/injection-types/#assisted-injection) on why in case you missed this! TL;DR, Metro matches by parameter names going forward.

compiler-tests/src/generator220/kotlin/dev/zacsweers/metro/compiler/GenerateTestsImpl.kt

@@ -8,6 +8,7 @@ import org.jetbrains.kotlin.generators.generateTestGroupSuiteWithJUnit5
 inline fun <
   reified Box,
   reified FastInitBox,
+  reified ContributionProvidersBox,
   reified Diagnostic,
   reified FirDump,
   reified IrDump,
@@ -23,6 +24,7 @@ inline fun <
       }
       testClass<Box> { commonModel("box") }
       testClass<FastInitBox> { commonModel("box") }
+      testClass<ContributionProvidersBox> { commonModel("box/aggregation") }
       testClass<Diagnostic> { commonModel("diagnostic") }
       testClass<FirDump> { commonModel("dump/fir") }
       testClass<IrDump> { commonModel("dump/ir") }

compiler-tests/src/generator230/kotlin/dev/zacsweers/metro/compiler/GenerateTestsImpl.kt

@@ -9,6 +9,7 @@ import org.jetbrains.kotlin.generators.dsl.junit5.generateTestGroupSuiteWithJUni
 inline fun <
   reified Box,
   reified FastInitBox,
+  reified ContributionProvidersBox,
   reified Diagnostic,
   reified FirDump,
   reified IrDump,
@@ -24,6 +25,7 @@ inline fun <
       }
       testClass<Box> { commonModel("box") }
       testClass<FastInitBox> { commonModel("box") }
+      testClass<ContributionProvidersBox> { commonModel("box/aggregation") }
       testClass<Diagnostic> { commonModel("diagnostic") }
       testClass<FirDump> { commonModel("dump/fir") }
       testClass<IrDump> { commonModel("dump/ir") }

compiler-tests/src/generator2320/kotlin/dev/zacsweers/metro/compiler/GenerateTestsImpl.kt

@@ -9,6 +9,7 @@ import org.jetbrains.kotlin.generators.dsl.junit5.generateTestGroupSuiteWithJUni
 inline fun <
   reified Box,
   reified FastInitBox,
+  reified ContributionProvidersBox,
   reified Diagnostic,
   reified FirDump,
   reified IrDump,
@@ -24,6 +25,7 @@ inline fun <
       }
       testClass<Box> { commonModel("box") }
       testClass<FastInitBox> { commonModel("box") }
+      testClass<ContributionProvidersBox> { commonModel("box/aggregation") }
       testClass<Diagnostic> { commonModel("diagnostic") }
       testClass<FirDump> { commonModel("dump/fir") }
       testClass<IrDump> { commonModel("dump/ir") }