refactor: convert events module to TS

[jaissica12]

Background

• As part of the ongoing effort to migrate the mParticle Web SDK from JavaScript to TypeScript, this PR converts the events module and its corresponding test file to TypeScript for improved type safety and developer experience.

What Has Changed

• Converted src/events.js to src/events.ts with full type annotations on all method parameters, return types, and internal variables
• Converted test/src/tests-event-logging.js to test/src/tests-event-logging.ts with proper global type declarations and type casts for intentionally invalid test inputs
• Updated src/events.interfaces.ts to expand the logImpressionEvent signature to accept SDKImpression | SDKImpression[] | SDKProductImpression | SDKProductImpression[]
• Minor supporting type adjustments in src/sdkRuntimeModels.ts, src/serverModel.ts, and src/store.ts

Screenshots/Video

Checklist

• I have performed a self-review of my own code.
• I have made corresponding changes to the documentation.
• I have added tests that prove my fix is effective or that my feature works.
• I have tested this locally.

Additional Notes

Reference Issue (For employees only. Ignore if you are an outside contributor)

• Closes https://go/j/SDKE-1106

[sonarqubecloud]

Quality Gate failed

Failed conditions
1 Security Hotspot
4.3% Duplication on New Code (required ≤ 3%)

See analysis details on SonarQube Cloud

[cursor]

PR Summary

Medium Risk
Refactors core event/commerce logging code to TypeScript and adjusts several public method signatures, which could introduce subtle runtime regressions around DOM handlers, location tracking, and ecommerce event shaping despite largely type-only intent.

Overview
Migrates the Events module to TypeScript with explicit typings for event logging, commerce helpers, DOM event handlers, and location tracking, including stricter error handling and attribute casting.

Expands commerce APIs to accept arrays in more places (e.g., logPromotionEvent) and broadens logImpressionEvent to support SDKImpression and lists, with minor supporting type updates in runtime models, server DTO conversion, and store config (timeout).

Converts the event logging test suite to TypeScript by adding global type declarations and using casts/String(...) coercions for intentionally invalid test inputs and mocked request bodies.

^{Reviewed by Cursor Bugbot for commit 14dfc68. Bugbot is set up for automated code reviews on this repo. Configure here.}

[cursor]

Cursor Bugbot has reviewed your changes and found 2 potential issues.

^{❌ Bugbot Autofix is OFF. To automatically fix reported issues with cloud agents, have a team admin enable autofix in the Cursor dashboard.}

^{Reviewed by Cursor Bugbot for commit 14dfc68. Configure here.}

[cursor]

Replacing self with this in regular functions risks broken context

Medium Severity

The original code used var self = this to lexically capture the Events instance, guaranteeing correct binding regardless of calling context. The refactored code replaces self with this inside regular (non-arrow) function expressions like logAST, logCheckoutEvent, logProductActionEvent, logPurchaseEvent, logRefundEvent, logPromotionEvent, and logImpressionEvent. Since these are not arrow functions, this is determined at call time. If any method is ever invoked without being called as a property of the Events object (e.g., stored in a variable, passed as a callback), this will be undefined in strict mode, causing a runtime crash. The project's tsconfig.json does not enable noImplicitThis, so the compiler won't catch this.

Additional Locations (2)

• src/events.ts#L149-L150
• src/events.ts#L346-L347

 

^{Reviewed by Cursor Bugbot for commit 14dfc68. Configure here.}

[cursor]

Unsafe cast silently mishandles SDKProductImpression input data

Medium Severity

The logImpressionEvent type signature now explicitly accepts SDKProductImpression | SDKProductImpression[], but the implementation unconditionally casts each item to SDKImpression via as SDKImpression and accesses .Name and .Product. SDKProductImpression has different properties (ProductImpressionList and ProductList), so passing one would silently produce impressions with undefined names and [undefined] product lists — silent data corruption with no error.

Additional Locations (1)

• src/events.interfaces.ts#L48-L49

 

^{Reviewed by Cursor Bugbot for commit 14dfc68. Configure here.}