feat: auto-calculate commerce event total amount from products

[jamesnrokt]

Summary

A commerce event's transaction-level Total Amount (ProductAction.TotalAmount) was only ever populated from a caller-supplied transactionAttributes.Revenue. When Revenue was omitted, the Web SDK left the total at 0 — even though each product's individual amount was recorded correctly. The result: multi-item checkouts reported every line item but a zero basket total.

This PR derives the total from the product list (Σ quantity × price) plus shipping and tax whenever the caller doesn't supply Revenue, bringing the Web SDK's behavior in line with mParticle's other platform SDKs.

Changes

• src/ecommerce.js — new calculateProductActionTotalAmount(productAction) helper: sums quantity × price across the product list, adds ShippingAmount and TaxAmount, and assigns the result to TotalAmount. A total the caller explicitly provided (including 0) is never overwritten.
• src/events.js — invoked from logCommerceEvent, the single chokepoint all commerce events flow through, so it applies uniformly to checkout, purchase, refund, add-to-cart, etc.
• test/src/tests-eCommerce.js — integration tests (auto-sum, shipping/tax included, explicit revenue not overridden) and unit tests for the helper.

Behavior change / compatibility

⚠️ This changes observed output for integrations that omit Revenue: they will now emit a non-zero Total Amount (tr / total_amount) downstream instead of 0. Integrations that pass Revenue are unaffected.

Testing

• npm test — 1090 passing, 0 failing (ChromeHeadless).

🤖 Generated with Claude Code

[cursor]

PR Summary

Medium Risk
Changes emitted commerce payload values for integrations that omit Revenue, which can affect downstream analytics and partner kits without touching auth or security.

Overview
Commerce events that omit transactionAttributes.Revenue now get ProductAction.TotalAmount filled from line items (Σ quantity × price) plus shipping and tax, instead of leaving the basket total at 0 while products still carry correct amounts.

A new calculateProductActionTotalAmount helper in ecommerce.js performs that math (via parseNumber). logCommerceEvent invokes it for every product-action commerce event before upload, so checkout, purchase, refund, and similar flows behave consistently. Explicit Revenue (including 0) is never overwritten.

Compatibility: downstream total_amount / tr will change for integrations that did not pass Revenue; callers that set Revenue are unchanged. Tests add integration and unit coverage for auto-sum, shipping/tax, and no-override behavior.

^{Reviewed by Cursor Bugbot for commit fd939eb. Bugbot is set up for automated code reviews on this repo. Configure here.}

[jaissica12]

@jamesnrokt small thing, can you retarget this to development development

[jamesnrokt]

@jamesnrokt small thing, can you retarget this to development development

Done

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[jaissica12]

LGTM 🚀