refactor(ios): move RoktContracts-typed code into a Swift layer

[thomson-t]

Why

React Native is moving apps to Swift Package Manager, and in that setup this package's Objective-C++ files cannot see the Rokt types they use today (the embedded view, events and config). The next pull request, an experimental package manifest for React Native's own Swift Package Manager mode, needs that code to live somewhere that can see them. Once this lands, all Rokt-typed logic is in Swift, and the Objective-C++ files only pass plain views and dictionaries through. Apps see no difference: the same events reach JavaScript, with the same contents, in the same order.

Programme

Part of the plan to support Swift Package Manager in this package before the CocoaPods central repository becomes read-only on 2026-12-02 (CocoaPods announcement). This is the fifth of eight pull requests, all merging into the workstation/spm-migration branch, which merges into main once the series is complete, and shipping together in one release; the plan record is internal and cannot be linked here.

What changes

Before: RoktEventManager.mm mapped every Rokt event type to its JavaScript payload, RNMPRokt.mm built the Rokt config and checked for embedded views, and the Fabric view created a RoktEmbeddedView directly. All of them imported the RoktContracts headers.

After: that logic is in three Swift classes in ios/RNMParticle/Swift/:

• RNMPRoktEventMapper: event to payload, plus the callback and height side events;
• RNMPRoktConfigFactory: dictionary to config;
• RNMPRoktViews: creates and recognises the embedded view.

The Objective-C++ files reach them through one hand-written header, RNMPRoktSwift.h, which uses only Foundation and UIKit types; the generated Swift header can't be reached from Objective-C++ under Swift Package Manager. No .mm file references RoktContracts any more, and the import header now gives RoktContracts to .m files only. The Fabric view's roktEmbeddedView property is typed UIView. The podspec gains swift_version, DEFINES_MODULE, private headers (so C++ and React headers stay out of the module), and, in Swift Package Manager mode, the Swift include path for the packages.

The tests were written first, against the original Objective-C, and pass unchanged against the Swift port:

• one test per Rokt event type, covering the payload and the extra events it triggers, in order;
• the config mapping, including which inputs mean "no config";
• a check that every selector declared in the hand-written header exists.

CI runs the three new test classes in both legs. No documentation change is needed; the changelog is generated by the release-draft workflow.

Start reading at RNMPRoktSwift.h, then RoktEventManager.mm (the event adapter), then the Swift files.

Linked work

Depends on: the Expo config plugin option (branch thomson-t/spm-04-expo-spm) and the pull requests below it in this series; merge those first.
Unblocks: the experimental Package.swift for React Native's Swift Package Manager mode (branch thomson-t/spm-06-package-swift).

Rollout

Path: this merges into workstation/spm-migration, not main, so nothing reaches main or a release until the whole series has merged there and that branch is merged into main. It then ships in the next release. It is live for every iOS app on that release.
Feature flags: none.
Turning it off: a published version cannot be recalled. Reverting this pull request and releasing again restores the Objective-C mapping in the next version.
What we watch: this repository's issues, for Rokt events missing or changed in JavaScript, embedded placements that stop resizing, and iOS build errors mentioning Swift.

Risks

• An event could reach JavaScript with a different payload; prevented because characterization tests for every event type were written against the Objective-C and pass against Swift, and the sample app showed the full event sequence and a resizing embedded view; we would see a missing or renamed field in an app's event handler.
• The hand-written header could drift from the Swift code; prevented because a test checks every declared selector exists; we would see an "unrecognized selector" crash.
• Apps that use static libraries without the pre_install dynamic-framework hook fail pod install ("Swift pod react-native-mparticle depends upon mParticle-Apple-SDK-ObjC, which does not define modules"); contained because the native mParticle-Apple-SDK pod already fails the same way in that setup, so the hook, or use_frameworks!, is already required; we would see that error reported against that release by an app that had worked before.
• Private headers could hide something an app imported from this pod; contained because React Native finds this package's modules and view by class name, and the sample, Expo and Swift Package Manager builds all passed; we would see a header-not-found error in an app.
• If any cacheAttributes value is not a string, the config factory drops the whole cacheAttributes map, where the Objective-C passed such values through unchecked (and they would have crashed when read); not addressed further, because the JavaScript type allows only strings; we would see cache attributes ignored.

Risk class: higher — this rewrites how every Rokt event and config reaches the SDK on iOS. Behaviour is pinned by tests written against the old code.

Who

Written by: an automated coding agent (Claude Code), at an engineer's request, following the internal Swift Package Manager migration plan and its proof of concept.
Code reviewed before opening: an independent review agent reviewed the change before it was committed.
Design reviewed before opening: the requesting engineer approved the plan's Swift-first layering, with hand-written Objective-C headers for the Swift classes.
Decision this implements: the requesting engineer's approval of the migration plan on 2026-09-28; the record is internal and cannot be linked.
Checked: on 2026-09-28, with Xcode 27.0 on an iOS 26.5 simulator, the sample app (React Native 0.84, New Architecture):

• Tests: the characterization tests passed against the Objective-C before the port, and all 54 unit tests pass after it, in both CocoaPods and Swift Package Manager mode.
• CocoaPods mode, and Swift Package Manager mode with static libraries and with dynamic frameworks: Release build and unsigned archive succeeded; one copy of each SDK class; embedded placements by name and by tag, and an overlay, rendered, with the events shown on screen and the embedded view resizing.
• Size: the archived app binary grew by 25.4 KB in CocoaPods mode and 0.8 KB in Swift Package Manager mode.
• Old Architecture: a React Native 0.81.5 app with the New Architecture off compiled this package; that app needed a local fix for React Native's own fmt dependency, which does not build with Xcode 27.
  Not checked: the Old Architecture at runtime; tvOS. CI, which builds with Xcode 16, passed on this pull request.

Size

Hand-written: about 515 lines added and 210 removed in 16 files; 284 of the added lines are tests, and the Swift and adapter code is about 230.
Generated: none.
Why one pull request: the tests pin the old behaviour and must land with the port they guard, and the adapters cannot switch to Swift one file at a time without leaving an Objective-C++ file that still needs the Rokt headers.

Notes for reviewers

Why hand-written headers. Under Swift Package Manager, Swift and Objective-C++ must be separate targets, and an Objective-C++ file can only reach another target's generated -Swift.h with C++ modules, which break React Native's headers. The mParticle SDK's MPRokt.h only forward-declares RoktEmbeddedView, RoktConfig and RoktEvent, so pointers to them still type-check in .mm files without the RoktContracts headers.

The characterization test's spy. RNMPRoktEventMapperTests swaps the event manager's class for a subclass that records sendEventWithName:body: instead of sending. The subclass adds no instance variables, so swapping the class of an existing instance is safe.

A clamp worth knowing. CacheConfig raises a zero duration to its 90-minute maximum. A config test now pins that, since the JavaScript wrapper sends 0 when the duration is missing.

🤖 Generated with Claude Code

[cursor]

PR Summary

Medium Risk
Refactors core native iOS event mapping and configuration bridging logic, though risks are mitigated by characterization unit tests.

Overview
Extracted RoktContracts-typed logic from Objective-C++ (.mm) into a dedicated Swift layer (RNMPRoktEventMapper, RNMPRoktConfigFactory, and RNMPRoktViews). Objective-C++ files now interact with these components using Foundation and UIKit types via a hand-written RNMPRoktSwift.h header, preparing the package for Swift Package Manager support where Objective-C++ cannot directly import generated Swift module headers.

Updated react-native-mparticle.podspec to configure Swift build settings (swift_version, DEFINES_MODULE, and private header isolation) and added comprehensive unit test suites for event mapping, configuration generation, and Swift selector verification.

^{Reviewed by Cursor Bugbot for commit 8fffd85. Bugbot is set up for automated code reviews on this repo. Configure here.}

[Copilot]

Copilot review overview

🟡 Changes recommended

The checked-in RNMParticle Xcode target does not compile the new Swift implementations referenced by its Objective-C++ sources.

Review effort: Balanced
Findings: 1

Open (1)

• Add Swift implementations to RNMParticle target Sources phase · New

What changed in this PR

Moves Rokt-typed iOS logic into Swift to support future Swift Package Manager integration while preserving the Objective-C++ bridge.

Changes:

• Adds Swift event, configuration, and embedded-view adapters.
• Updates Objective-C++ callers and CocoaPods settings.
• Adds characterization tests to both CI modes.

File	Description
.github/​workflows/​pull-request.yml	Runs new iOS tests.
react-native-mparticle.podspec	Configures Swift and module support.
ios/​RNMParticle/​RNMPRoktSwift.h	Declares the Swift bridge API.
ios/​RNMParticle/​RNMPSDKImports.h	Restricts RoktContracts imports to Objective-C.
ios/​RNMParticle/​RNMPRokt.mm	Uses Swift config and view adapters.
ios/​RNMParticle/​RoktEventManager.mm	Delegates event mapping to Swift.
ios/​RNMParticle/​RoktNativeLayoutComponentView.h	Exposes the embedded view as UIView.
ios/​RNMParticle/​RoktNativeLayoutComponentView.mm	Creates embedded views through Swift.
ios/​RNMParticle/​Swift/​RNMPRoktEventMapper.swift	Maps Rokt events and side effects.
ios/​RNMParticle/​Swift/​RNMPRoktConfigFactory.swift	Builds Rokt configuration objects.
ios/​RNMParticle/​Swift/​RNMPRoktViews.swift	Creates and identifies embedded views.
ios/​RNMParticle.xcodeproj/​project.pbxproj	Adds the bridge header, but omits Swift sources.
sample/​ios/​MParticleSampleTests/​RNMPRoktEventMapperTests.m	Characterizes event payloads and ordering.
sample/​ios/​MParticleSampleTests/​RNMPRoktConfigFactoryTests.m	Tests configuration conversion.
sample/​ios/​MParticleSampleTests/​RNMPRoktSwiftTests.m	Verifies bridge selectors and types.
sample/​ios/​MParticleSample.xcodeproj/​project.pbxproj	Registers the new tests.

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.

[thomson-t]

Not changing this here. ios/RNMParticle.xcodeproj is not a working build path today. On main, before this stack, a standalone build fails, first on its 12.4 deployment target and then on its recursive React header search paths. Its mParticle header paths also point at the old pre-9.x pod layout, and it has none for RoktContracts. The supported integrations build these files through the podspec or Package.swift. Removing the project would be a separate change.