Tracking: expand Sentry JS SDK feature coverage

[zivl]

Background

A review of the Sentry JavaScript SDK docs against sentry-testkit found that the testkit currently captures only 2 of the ~12 envelope item types the SDK can emit (event and transaction). Everything Sentry shipped in recent years — structured logs, session replay, user feedback, cron check-ins, sessions/release health, standalone spans, metrics, attachments, client reports — is silently dropped by the transport/parser layer.

This issue tracks the incremental rollout of full SDK coverage. Each item below is an independent issue that can ship as its own release (conventional commits + release-please), roughly ordered by expected user value.

Roadmap

Prerequisite

• Rewrite envelope parser to support multi-item envelopes #299 Rewrite envelope parser to support multi-item envelopes — blocks all data-type issues below

New data-type capture APIs (ordered by expected value)

• Support Structured Logs: capture log envelope items via testkit.logs() #300 Structured Logs → testkit.logs()
• Support User Feedback: capture feedback envelope items via testkit.feedback() #301 User Feedback → testkit.feedback()
• Support Cron Check-Ins: capture check_in envelope items via testkit.checkIns() #302 Cron Check-Ins → testkit.checkIns()
• Support Sessions / Release Health: capture session envelope items via testkit.sessions() #303 Sessions / Release Health → testkit.sessions()
• Support Session Replay: capture replay envelope items via testkit.replays() #304 Session Replay → testkit.replays()
• Support standalone spans & AI agent monitoring: testkit.spans() / findSpansByOp() #305 Standalone spans & AI agent monitoring → testkit.spans() / findSpansByOp()
• Support Application Metrics: capture trace_metric envelope items via testkit.metrics() #306 Application Metrics → testkit.metrics()
• Support Attachments: capture attachment envelope items #307 Attachments
• Support Client Reports: capture client_report envelope items via testkit.clientReports() #308 Client Reports → testkit.clientReports()

DX / API improvements (independent of the parser work — can ship anytime)

• Add awaitable assertions: waitForReports() / waitForTransactions() #309 Awaitable assertions: waitForReports() / waitForTransactions()
• Add richer query helpers: findTransaction, findReportByMessage, reportsWithTag #310 Richer query helpers: findTransaction, findReportByMessage, reportsWithTag
• Expose feature flags on reports: report.flags from contexts.flags #311 Expose feature flags: report.flags
• Add Playwright integration: testkit.playwright.startListening(page) #312 Playwright integration

Suggested release sequence

1. Quick DX wins that need no parser changes: Add awaitable assertions: waitForReports() / waitForTransactions() #309, Add richer query helpers: findTransaction, findReportByMessage, reportsWithTag #310, Expose feature flags on reports: report.flags from contexts.flags #311
2. The enabler: Rewrite envelope parser to support multi-item envelopes #299
3. Data types in value order: Support Structured Logs: capture log envelope items via testkit.logs() #300 → Support User Feedback: capture feedback envelope items via testkit.feedback() #301 → Support Cron Check-Ins: capture check_in envelope items via testkit.checkIns() #302 → Support Sessions / Release Health: capture session envelope items via testkit.sessions() #303 → Support Session Replay: capture replay envelope items via testkit.replays() #304 → Support standalone spans & AI agent monitoring: testkit.spans() / findSpansByOp() #305 → Support Application Metrics: capture trace_metric envelope items via testkit.metrics() #306 → Support Attachments: capture attachment envelope items #307 → Support Client Reports: capture client_report envelope items via testkit.clientReports() #308
4. Add Playwright integration: testkit.playwright.startListening(page) #312 Playwright integration (basic capture works today; benefits from Rewrite envelope parser to support multi-item envelopes #299 for new item types)