[workflows] Local `delete()` and `deleteBatch()` have no test coverage

[petebacondarwin]

Split out of #15123 so that PR can land. Raised by Devin: #15123 (comment)

Problem

The local WorkflowInstance.delete() and Workflow.deleteBatch() support added in #15123 has no test coverage. Confirmed: packages/workflows-shared/tests/ contains no reference to delete, and no test file in the repo references deleteBatch.

Untested code paths:

• packages/workflows-shared/src/binding.ts:243 — WorkflowBinding.deleteBatch()
• packages/workflows-shared/src/binding.ts:522 — WorkflowHandle.delete()
• packages/miniflare/src/workers/workflows/wrapped-binding.worker.ts:37 — deleteBatch() wrapper
• packages/miniflare/src/workers/workflows/wrapped-binding.worker.ts:137 — delete() wrapper

There is an existing suite at packages/workflows-shared/tests/binding.test.ts covering create, get, createBatch and WorkflowHandle, so there is a clear home for these.

Worth covering

• Deleting a running instance, and that it is actually gone afterwards.
• Deleting an instance ID that does not exist.
• The batch guard rails: the empty-batch and >100-instance errors (binding.ts:246-256).
• Duplicate IDs within one batch.
• The deleted/errors split — note this is currently broken (see [workflows] Local deleteBatch() always reports success, so failures are invisible #15138), so these tests should be written against the intended semantics decided there, and will likely land with that fix.

Acceptance

• delete() and deleteBatch() are covered in packages/workflows-shared/tests/binding.test.ts, including at least one case that asserts a failure is reported rather than being reported as a success.

[workers-devprod]

Note

This is an automated, advisory triage report generated by workers-devprod. It is not an official maintainer response — a maintainer will follow up.

🤖 Automated triage report

Issue Triage: #15139

Summary

Tracking issue to add missing test coverage for the local WorkflowInstance.delete() and Workflow.deleteBatch() support introduced in #15123.

Classification

• Type: Task (internal engineering / test-coverage tracking)
• Component: packages/workflows-shared (with related wrappers in packages/miniflare)
• Severity: Low (no user-facing bug; missing test coverage)
• Has Reproduction: N/A (not a bug report)
• Quality: Complete

Findings

• Created: not fully visible in pre-fetched data
• Author: petebacondarwin (Pete Bacon Darwin — core maintainer)
• Version: not applicable (internal task)
• Labels: not fully visible in pre-fetched data
• Comments: 1 (an automated advisory triage-report comment from workers-devprod)

Analysis

• This is a maintainer-authored internal task, split out of PR Bump the workerd-and-workers-types group across 1 directory with 2 updates #15123 so that PR could land. It is a well-scoped, actionable tracking issue — not a user bug report or spam.
• Component is clearly identified by the author with precise file/line references: packages/workflows-shared/src/binding.ts (deleteBatch() at :243, WorkflowHandle.delete() at :522) and packages/miniflare/src/workers/workflows/wrapped-binding.worker.ts (:37, :137). The existing home for these tests is packages/workflows-shared/tests/binding.test.ts.
• The issue includes explicit acceptance criteria and a detailed list of cases worth covering (deleting running instances, non-existent IDs, batch guard rails, duplicate IDs, the deleted/errors split).
• It has a cross-dependency: the deleted/errors split behaviour is noted as currently broken ([workflows] Local deleteBatch() always reports success, so failures are invisible #15138), so some tests should be written against the semantics decided there and will likely land with that fix.
• No closeable condition applies (not spam, not stale, not a duplicate, not resolved, not wrong-repo). It should remain open as a tracking item.

Recommendation

Status: KEEP OPEN

Reasoning: This is a legitimate, well-scoped internal task authored by a core maintainer with clear file references and acceptance criteria. It represents real, actionable work (adding test coverage for recently added delete functionality) and has no reason to be closed.

Action: Leave open as a tracking item. Ensure the deleted/errors split tests are coordinated with the fix in #15138. Good candidate for a good first issue given the clear scope and existing test suite to build on, if the semantics from #15138 are settled first.

Suggested Labels: none (existing repo labels not verifiable from the pre-fetched data; omitting rather than guessing)

Suggested Comment

This is a valid internal test-coverage task with clear scope and acceptance criteria — keeping it open. Note the deleted/errors split tests depend on the semantics being resolved in #15138, so those cases should land alongside that fix.

Structured summary (JSON)

{
  "issueNumber": 15139,
  "title": "Add test coverage for local WorkflowInstance.delete() and Workflow.deleteBatch()",
  "githubUrl": "https://github.com/cloudflare/workers-sdk/issues/15139",
  "recommendation": "KEEP OPEN",
  "difficulty": "medium",
  "reasoning": "Well-scoped internal test-coverage task authored by a core maintainer with precise file references and explicit acceptance criteria. It is real, actionable work with no reason to close.",
  "suggestedAction": "Leave open as a tracking item; coordinate the deleted/errors split tests with the fix in #15138 before landing those cases.",
  "hasSuggestedComment": true,
  "suggestedLabels": []
}

[workers-devprod]

• Reproduction: ✅ Successfully reproduced. Checked out PR Bump the workerd-and-workers-types group across 1 directory with 2 updates #15123 branch and confirmed the four untested code paths exist (WorkflowBinding.deleteBatch() at packages/workflows-shared/src/binding.ts:243, WorkflowHandle.delete() at packages/workflows-shared/src/binding.ts:522, and the two wrappers in packages/miniflare/src/workers/workflows/wrapped-binding.worker.ts:37 and :137). Grepped packages/workflows-shared/tests/binding.test.ts and the broader test directories—zero references to delete or deleteBatch. Ran the existing pnpm run test:ci suite for workflows-shared; all 153 tests pass, confirming these methods are entirely uncovered.