…3636)

### Motivation

Follow-up to #3603 (cc @vegaro). That PR threads `presented_workflow_id`
/ `presented_step_id` through the post-receipt pipeline. While reviewing
it I found two coverage gaps, one of which is significant. This PR
**targets the #3603 branch** so the tests land with the feature.

### Changes

**1. `PostReceiptHelper` resolution coverage** (`PostReceiptHelperTest`)

The new resolution logic in `PostReceiptHelper` was only exercised
indirectly (`BackendTest` covers the wire format given explicit
metadata; `PaywallViewModelWorkflowTest` covers event creation). Added:

- resolves workflow metadata from the live presented paywall event
- omits workflow metadata when the presented event has no workflow (pins
the "both-or-neither" rule of `WorkflowMetadata.from`)
- replays cached workflow metadata on unsynced retry
(`postRemainingCachedTransactionMetadata`)

Supporting: `mockPostReceiptSuccess` now matches `workflowMetadata =
any()` (an omitted defaulted arg in MockK binds `eq(null)`), so the
success path can post non-null workflow metadata. Existing tests
unaffected.

**2. Fixed a vacuous re-presentation test + added EXIT_OFFER coverage**
(`PaywallViewModelWorkflowTest`)

The feature's own regression test, `purchase initiated after same
paywall workflow re-presentation carries current step metadata`, did
**not** actually exercise `withCurrentWorkflowMetadata`. Its two steps
pointed at different screens (`screen-1` vs `screen-2`), producing
different presentation fingerprints, so the second impression took the
**else** branch and recreated fresh event data, reading the live step.
The test passed even with `withCurrentWorkflowMetadata` removed.

- Reworked that test so both steps render the **same screen** (identical
fingerprint → de-dup branch is taken), with a "no new impression"
assertion proving the branch was reached.
- Added a sibling test for `EXIT_OFFER` after the same-fingerprint
re-presentation.
- Both verified **RED → GREEN**: with `withCurrentWorkflowMetadata`
neutralized they fail (`expected "step-2" but was "step-1"`); restored,
they pass.

### Validation

- `./gradlew :purchases:testDefaultsBc8DebugUnitTest --tests
"com.revenuecat.purchases.PostReceiptHelperTest"` , 86 tests, 0
failures.
- `./gradlew :ui:revenuecatui:testDefaultsBc8DebugUnitTest --tests
"com.revenuecat.purchases.ui.revenuecatui.data.PaywallViewModelWorkflowTest"`
, 0 failures.
- RED→GREEN proof captured by neutralizing the
`withCurrentWorkflowMetadata` line (run under JDK 21).

> [!IMPORTANT]
> Before #3603 merges: its `withCurrentWorkflowMetadata` change had no
test that exercised it (the existing regression test was vacuous). This
PR closes that gap. Recommend not approving #3603 until these tests are
in.

<details>
<summary>AI session context</summary>

# AI Context

## Metadata

- PR: this PR (base: `cesar/receipt-presented-paywall-workflow-ids`, the
#3603 branch)
- Branch: `facu/pr3603-postreceipt-workflow-tests`
- Author / human owner: facumenzella
- Agent(s): Claude Code, Opus 4.8 (1M context)
- Session source: current conversation
- Generated: 2026-06-22
- Context document version: 2

## Goal

Close test-coverage gaps found while reviewing #3603: (a)
`PostReceiptHelper`-layer workflow-metadata resolution, and (b) the
`withCurrentWorkflowMetadata` re-presentation behavior, whose existing
regression test turned out to be vacuous.

## Initial Prompt

Review #3603. The review surfaced coverage gaps; follow-ups were "write
a test for 1", "open a draft targeting this pr and mention this", then
"write it [finding #2] and put it in the same pr".

## Important Follow-up Prompts

- "Can you write a test for 1" , PostReceiptHelper coverage.
- "open a draft targetting this pr and mention this" , open this PR
against the #3603 branch.
- "write it and put it in the same pr" , add the finding #2
(CLOSE/EXIT_OFFER) test.
- Decision: "Fix it in my PR" , rework vegaro's vacuous
PURCHASE_INITIATED test here rather than only flagging it.

## Agent Contribution

- Added 3 `PostReceiptHelperTest` tests + made `mockPostReceiptSuccess`
workflow-agnostic.
- Added an `EXIT_OFFER` re-presentation test in
`PaywallViewModelWorkflowTest`.
- Discovered (via a neutralize + sentinel experiment) that the existing
PURCHASE_INITIATED re-presentation test never reached the
`withCurrentWorkflowMetadata` branch; reworked it to share one screen
and added a "no new impression" guard.
- Verified RED→GREEN for both UI tests by neutralizing the production
line.

## Human Decisions

- Open a separate branch / draft PR against the #3603 feature branch
rather than pushing onto @vegaro's branch.
- Fix the vacuous existing test inside this PR.

## Key Implementation Decisions

- Decision: force the same presentation fingerprint by pointing both
workflow steps at the same `screenId`.
- Rationale: the de-dup branch (where `withCurrentWorkflowMetadata`
lives) only runs when fingerprints match; different screens silently
routed the test through fresh re-creation.
- Rejected: leaving the original different-screen fixture (it does not
test the fix).
- Decision: assert "no new IMPRESSION" after the re-presentation.
- Rationale: proves the de-dup branch was taken; this is the guard that
distinguishes a real test from a vacuous one.
- Decision: `mockPostReceiptSuccess` uses `workflowMetadata = any()`.
  - Rationale: omitted defaulted MockK arg binds `eq(null)`.

## Files / Symbols Touched

-
`purchases/src/test/java/com/revenuecat/purchases/PostReceiptHelperTest.kt`
  - Why: PostReceiptHelper-layer resolution coverage.
- Symbols: `mockPostReceiptSuccess`, new `@Test`s (presented-paywall
resolution, no-workflow omission,
`postRemainingCachedTransactionMetadata`).
-
`ui/revenuecatui/src/test/kotlin/com/revenuecat/purchases/ui/revenuecatui/data/PaywallViewModelWorkflowTest.kt`
- Why: make the re-presentation test exercise
`withCurrentWorkflowMetadata`; add EXIT_OFFER coverage.
- Symbols: `purchase initiated after same paywall workflow
re-presentation...`, `exit offer after same paywall workflow
re-presentation...`.

## Dependencies / Config / Migrations

- None.

## Validation

- Commands run:
- `:purchases:testDefaultsBc8DebugUnitTest --tests
"...PostReceiptHelperTest"`: 86 tests, 0 failures.
- `:ui:revenuecatui:testDefaultsBc8DebugUnitTest --tests
"...PaywallViewModelWorkflowTest"`: 0 failures.
- RED check: with `withCurrentWorkflowMetadata` neutralized, both
re-presentation tests fail (`expected "step-2" but was "step-1"`);
restored, they pass.
- Manual verification: Not run (test-only change).
- CI: Not captured at time of writing.

## Validation Gaps

- The cached-vs-live precedence in `PostReceiptHelper` is exercised via
the live and retry paths but not via a dedicated synchronous-purchase
test where `getLocalTransactionMetadata` returns metadata.
- Local runs required JDK 21 (project `.sdkmanrc` pins `21.0.6-librca`);
default daemon here was JDK 17, which Robolectric rejects for Android
SDK 36.

## Review Focus

- Confirm the "no new impression" assertion correctly captures the
de-dup branch for both UI tests.
- Confirm `mockPostReceiptSuccess`'s `workflowMetadata = any()`
relaxation does not weaken the negative-case test (`...has no
workflow`), which asserts `workflowMetadata = null` explicitly.

## Risks / Reviewer Notes

- Risk: test-only change; no production behavior altered.
- Evidence: diff touches only `*Test.kt` files (the PaywallViewModel
edit during RED→GREEN was reverted; prod tree confirmed clean).
  - Mitigation: none needed.

## Non-goals / Out of Scope

- No production code changes; `withCurrentWorkflowMetadata` itself is
unchanged.

## Omitted Context

- Raw transcript, unrelated exploration, sensitive details, repetitive
attempts, and chain-of-thought-style content were omitted.

</details>

---------

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>