Add kotlin-tooling-cocoapods-to-spm-migration skill

Author: dayanruben

skills/kotlin-tooling-cocoapods-to-spm-migration/SKILL.md

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+---
+name: kotlin-tooling-cocoapods-to-spm-migration
+description: >
+  Migrate Kotlin Multiplatform (KMP) projects from CocoaPods integration to
+  Swift Package Manager import. Covers swiftPMDependencies adoption,
+  CocoaPods cleanup, Kotlin import rewrites, Xcode reconfiguration, and common
+  interoperability issues such as bundled klibs and Firebase or Google SDK
+  migration. Use when replacing kotlin("native.cocoapods"), migrating pod()
+  declarations, or updating imports from cocoapods.* to swiftPMImport.*.
+license: Apache-2.0
+metadata:
+  author: JetBrains
+  version: "1.0.0"
+---
+
+# CocoaPods to SwiftPM Migration for KMP
+
+Migrate Kotlin Multiplatform projects from `kotlin("native.cocoapods")` to
+`swiftPMDependencies {}`.
+
+## Requirements
+
+- **Kotlin**: Version with Swift Import support (for example `2.4.0-Beta1` or later)
+- **Xcode**: `16.4` or `26.0+`
+- **iOS deployment target**: `16.0+` recommended
+
+## Migration Overview
+
+**Important:** Keep the `cocoapods {}` block and plugin active until Phase 6.
+The migration adds `swiftPMDependencies {}` alongside the existing CocoaPods
+setup first, reconfigures Xcode, and only then removes CocoaPods.
+
+| Phase | Action |
+| --- | --- |
+| 1 | Analyze the existing CocoaPods configuration |
+| 2 | Update Gradle configuration (repositories, Kotlin version) |
+| 3 | Add `swiftPMDependencies {}` alongside `cocoapods {}` |
+| 4 | Transform Kotlin imports |
+| 5 | Reconfigure the iOS project and deintegrate CocoaPods |
+| 6 | Remove CocoaPods plugin and Gradle configuration |
+| 7 | Verify Gradle and Xcode builds |
+| 8 | Write `MIGRATION_REPORT.md` |
+
+## Phase 1: Pre-Migration Analysis
+
+### 1.0 Verify the project builds
+
+Before changing anything, identify the module that uses CocoaPods and confirm it
+builds successfully.
+
+1. Find `build.gradle.kts` files containing `cocoapods`.
+2. Extract the KMP module name from the path.
+3. Build only that module with `./gradlew :moduleName:build`.
+4. If the targeted build fails, ask the user either:
+   - to provide the correct build command, or
+   - to confirm the module is in a working state and it is safe to proceed.
+
+If the user confirms without a successful pre-migration build, record that
+verification could not be completed and call it out again in Phase 7.
+
+### 1.0a Confirm Kotlin version with Swift Import support
+
+Ask the user whether the project already uses a Kotlin version with
+`swiftPMDependencies` support.
+
+- If **yes**, read the current Kotlin version and skip Phase 2.2.
+- If **no**, ask for:
+  - the target Kotlin version, and
+  - whether that version requires a custom Maven repository.
+
+Compare the current and target **major.minor** Kotlin versions. If the change is
+large, warn that the version jump may introduce unrelated breaking changes and
+recommend updating Kotlin first, verifying the build, and then re-running the
+migration.
+
+### 1.1 Check for deprecated CocoaPods workaround property
+
+Search `gradle.properties` for:
+
+```properties
+kotlin.apple.deprecated.allowUsingEmbedAndSignWithCocoaPodsDependencies=true
+```
+
+Record whether it exists. After migration, this property is no longer needed and
+must be removed in Phase 6.
+
+### 1.2 Check for EmbedAndSign disablers
+
+Search all `build.gradle.kts` files for logic that disables `EmbedAndSign`
+tasks, such as `taskGraph.whenReady` filters or `tasks.matching` blocks.
+These CocoaPods-era workarounds will break `integrateEmbedAndSign` and must be
+removed before Phase 5 succeeds.
+
+See [references/troubleshooting.md](references/troubleshooting.md).
+
+### 1.3 Check for third-party KMP libraries with bundled cinterop klibs
+
+Some KMP libraries ship pre-built cinterop klibs that use the
+`cocoapods.*` namespace. Those imports must be preserved after migration,
+because the bindings come from the library's bundled klib rather than actual
+CocoaPods infrastructure.
+
+Known example:
+
+| Library | Maven artifact | Bundled namespace |
+| --- | --- | --- |
+| KMPNotifier | `io.github.mirzemehdi:kmpnotifier` | `cocoapods.FirebaseMessaging` |
+
+To detect this:
+
+1. Search Gradle dependencies for known KMP wrapper libraries.
+2. Find all `import cocoapods.*` statements in Kotlin sources.
+3. Cross-reference the imports against the bundled namespaces provided by those
+   libraries.
+4. Mark the imports that must stay unchanged in Phase 4.
+
+If needed, inspect downloaded klibs with `klib dump-metadata-signatures`.
+
+### Record these findings
+
+1. CocoaPods configuration blocks.
+2. Pod names, versions, and `linkOnly` flags.
+3. `cocoapods.framework {}` settings such as `baseName`, `isStatic`, and
+   deployment target.
+4. All `cocoapods.*` imports and whether they should be migrated or preserved.
+5. The iOS project directory containing `Podfile` and `.xcworkspace`.
+6. Whether the project uses non-KMP CocoaPods in the iOS app.
+7. Whether the Xcode project has commented-out or broken `embedAndSign` phases.
+8. Whether Crashlytics dSYM upload scripts point at CocoaPods paths.
+9. Any extra CocoaPods-specific build logic. See
+   [references/cocoapods-extras-patterns.md](references/cocoapods-extras-patterns.md).
+
+## Phase 2: Gradle Configuration
+
+Do **not** upgrade Gradle, KSP, or unrelated dependencies during this migration.
+Only make the changes needed for SwiftPM import support.
+
+### 2.1 Add custom Maven repository when required
+
+If the chosen Kotlin version needs a custom repository, add it to
+`settings.gradle.kts` in both `pluginManagement.repositories` and
+`dependencyResolutionManagement.repositories`.
+
+### 2.2 Update Kotlin version when required
+
+If the project is not already on a Kotlin version with Swift Import support,
+update the Kotlin version in the version catalog or build scripts to the value
+confirmed in Phase 1.0a.
+
+### 2.3 Add buildscript constraint if `swiftPMDependencies` is unresolved
+
+```kotlin
+buildscript {
+    dependencies.constraints {
+        "classpath"("org.jetbrains.kotlin:kotlin-gradle-plugin:<kotlin-version>!!")
+    }
+}
+```
+
+## Phase 3: Add `swiftPMDependencies` While Keeping CocoaPods
+
+Do **not** remove the `cocoapods {}` block or `kotlin("native.cocoapods")`
+plugin yet.
+
+### 3.1 Add `group`
+
+Ensure the module sets a stable `group`, because the generated Kotlin import
+namespace depends on it.
+
+```kotlin
+group = "org.example.myproject"
+```
+
+### 3.2 Add `swiftPMDependencies`
+
+Add a `swiftPMDependencies {}` block that mirrors the existing pod usage.
+Use [references/common-pods-mapping.md](references/common-pods-mapping.md) to
+map each pod to:
+
+- the Swift package repository URL,
+- the SPM products to link, and
+- the `importedModules` list when the Clang module name differs from the
+  product name.
+
+Key rules:
+
+- `products` control linking.
+- `importedModules` control cinterop generation when
+  `discoverModulesImplicitly = false`.
+- Do not split a shared library suite across CocoaPods and SPM. Migrate the
+  full suite together, especially Firebase.
+
+### 3.3 Move framework configuration out of `cocoapods`
+
+If the project configures `framework {}` inside `cocoapods`, move that
+configuration to `binaries.framework {}` on the iOS targets.
+
+Prefer `isStatic = true`. It is strongly recommended in general and required for
+some CocoaPods-era KMP wrapper libraries such as `dev.gitlive:firebase-*`.
+
+### 3.4 Handle wrapper libraries such as `dev.gitlive:firebase-*`
+
+If the project uses wrapper libraries with CocoaPods-era linker metadata:
+
+1. Switch the framework to `isStatic = true`.
+2. Add framework search paths or `linkerOpts` as needed.
+3. Re-run `integrateLinkagePackage` after product changes.
+
+See [references/common-pods-mapping.md](references/common-pods-mapping.md) and
+[references/troubleshooting.md](references/troubleshooting.md).
+
+### 3.5 Add language settings
+
+```kotlin
+sourceSets.configureEach {
+    languageSettings {
+        optIn("kotlinx.cinterop.ExperimentalForeignApi")
+    }
+}
+```
+
+For DSL details, see [references/dsl-reference.md](references/dsl-reference.md).
+
+## Phase 4: Kotlin Source Updates
+
+### Import namespace formula
+
+```
+swiftPMImport.<group>.<module>.<ClassName>
+```
+
+Where:
+
+- `group` comes from `build.gradle.kts`, with `-` converted to `.`
+- `module` comes from the Gradle module name, with `-` converted to `.`
+- `ClassName` is the Objective-C class name
+
+### Example
+
+```kotlin
+// BEFORE
+import cocoapods.FirebaseAnalytics.FIRAnalytics
+
+// AFTER
+import swiftPMImport.org.example.myproject.shared.FIRAnalytics
+```
+
+### Preserve bundled klib imports
+
+Do **not** replace `cocoapods.*` imports that come from bundled third-party
+klibs identified in Phase 1.3. Those imports should stay unchanged.
+
+### Bulk replacement approach
+
+Use a scoped regex replacement across Kotlin source files, excluding preserved
+imports:
+
+```text
+Find:    cocoapods\.\w+\.
+Replace: swiftPMImport.<group>.<module>.
+```
+
+Then manually restore any imports that should remain `cocoapods.*`.
+
+## Phase 5: iOS Project Reconfiguration
+
+### 5.1 Run the integration tasks
+
+Build the iOS workspace to capture the Gradle integration command. Then run the
+project-specific `integrateEmbedAndSign` and `integrateLinkagePackage` tasks.
+
+After running them:
+
+1. Verify `embedAndSignAppleFrameworkForXcode` is active in the Xcode project.
+2. Disable `ENABLE_USER_SCRIPT_SANDBOXING`.
+3. Restart the Gradle daemon with `./gradlew --stop`.
+
+If `integrateEmbedAndSign` is skipped or the build phase remains commented out,
+check again for EmbedAndSign disablers and see
+[references/troubleshooting.md](references/troubleshooting.md).
+
+### 5.2 Update Crashlytics scripts when needed
+
+If the iOS app uses Crashlytics, update dSYM upload scripts from CocoaPods paths
+to the SPM checkout path.
+
+### 5.3 Deintegrate CocoaPods
+
+Choose one of these paths:
+
+- **Option A:** Full deintegration when CocoaPods was only used for the KMP
+  framework.
+- **Option B:** Partial removal when non-KMP CocoaPods remain in the iOS app.
+
+Do not guess. Base the cleanup path on the findings from Phase 1.
+
+### 5.4 Manual fallback
+
+If automatic integration fails, use the manual steps from
+[references/troubleshooting.md](references/troubleshooting.md).
+
+## Phase 6: Remove CocoaPods from Gradle
+
+Only after Xcode has been reconfigured successfully:
+
+1. Remove `kotlin("native.cocoapods")` from `plugins`.
+2. Delete the `cocoapods {}` block.
+3. Remove deprecated properties from `gradle.properties`.
+4. Remove obsolete CocoaPods-specific tasks and build logic.
+
+For cleanup patterns, see
+[references/cocoapods-extras-patterns.md](references/cocoapods-extras-patterns.md).
+
+## Phase 7: Verification
+
+Run the migrated module build:
+
+```bash
+./gradlew :moduleName:build
+./gradlew :moduleName:linkDebugFrameworkIosSimulatorArm64
+```
+
+Then build the iOS app with `xcodebuild`, using:
+
+- `.xcodeproj` if all CocoaPods were removed, or
+- `.xcworkspace` if non-KMP CocoaPods remain.
+
+If the pre-migration build was not verified, explicitly warn that current build
+failures may include pre-existing issues.
+
+Do **not** revert the migration as a first response. Read the failure logs,
+re-check the migration phases, and use the troubleshooting guide.
+
+## Phase 8: Migration Report
+
+Write `MIGRATION_REPORT.md` in the project root using
+[references/migration-report-template.md](references/migration-report-template.md).
+
+The report must cover:
+
+1. Pre-migration state and project-specific anomalies.
+2. Exact changes made in each migration phase.
+3. Every import transformation, including preserved `cocoapods.*` imports.
+4. Errors encountered, root causes, and fixes.
+5. Non-trivial decisions such as `isStatic`, preserved imports, and framework
+   search paths.
+6. A complete file list of created, modified, and deleted files.
+
+## Additional Resources
+
+- [references/dsl-reference.md](references/dsl-reference.md)
+- [references/common-pods-mapping.md](references/common-pods-mapping.md)
+- [references/cocoapods-extras-patterns.md](references/cocoapods-extras-patterns.md)
+- [references/troubleshooting.md](references/troubleshooting.md)
+- [references/migration-report-template.md](references/migration-report-template.md)