Specify cleanup failure reporting — Discover and trace

PART I

Warm-up

Reconnect with a useful idea before starting specify cleanup failure reporting. In one or two sentences, describe the input, output or host boundary from the previous exercise that this lesson builds on. If you are arriving directly, skim the worked example first; there is no locked prerequisite.

A rough note is enough. You can revise it after the example.

PART II

Instruction & guided example

Trace independent task and cleanup outcomes

Cleanup is an operation that can fail after the user’s main task succeeds or fails. Track the two outcomes separately. A useful report names the affected resource class, impact, retained ownership and next safe action without exposing private contents or promising secure physical erasure.

Exercise export X succeeds and produces an approved download. Scratch files A(12 MiB) and B(8 MiB) should then be removed. Host removal of A succeeds, removal of B returns an access-denied outcome. A cleanup coordinator owns retries with a stated budget; no concrete deletion/retry API is supplied by the WillowScript source.

Supplied case: Export X completed. Cleanup removed A12 but could not remove B8.

Worked reasoning: The export outcome remains completed, while cleanup is partial with 8 MiB retained. Report both facts. Do not erase the successful export outcome or claim all scratch storage was reclaimed.

Contrast and diagnosis: A single all-success flag hides B; a single all-failure flag falsely says the export itself failed.

Worked reasoning and supplied artifact

// Disposable exercise fixture / host-contract notes; not executable API syntax.
// Supplied input: Export X completed. Cleanup removed A12 but could not remove B8.
// Worked prediction: The export outcome remains completed, while cleanup is partial with 8 MiB retained. Report both facts. Do not erase the successful export outcome or claim all scratch storage was reclaimed.
// Rejected alternative: A single all-success flag hides B; a single all-failure flag falsely says the export itself failed.

Illustrative example from the proposed WillowScript design. The language and WUIX/WMATH/WDB/WAUDIO/WTMP services are not implemented in the supplied source. This site has no interpreter, VM or native host and does not execute or certify the snippet.

Try the guided change

Reconstruct the supplied worked case first: list its inputs, intermediate decisions and final artifact. Compare each row with the explanation and identify exactly where the rejected alternative fails. Then use the changed inputs in Part IV for independent work.

• Write the supplied inputs and initial state before following the example.
• Reconstruct each intermediate calculation or host decision, then compare with the worked artifact.
• Explain why the contrasting alternative fails before attempting the changed inputs in Part IV.

PART III

Take a breather

Step back after the guided example. Look away from the screen, stretch, or reread your prediction. This is an optional learning pause, not a timer or an assessment gate.

When you return, try to name the lesson’s key idea without copying its wording. If that feels difficult, return to Part II and trace one line rather than restarting the entire lesson.

PART IV

Independent practice

Project context: Resource budget dashboard. Build a small, understandable change around specify cleanup failure reporting.

Use completed export Y with scratch sizes 6 and 14, first removal fails and second succeeds. Write task status, cleanup status and remaining bytes.

What to produce

Use completed export Y with scratch sizes 6 and 14, first removal fails and second succeeds. Write task status, cleanup status and remaining bytes. Include input → intermediate decision/state → predicted outcome, with any required host rule stated explicitly.

• State the intended behavior in a sentence before editing.
• Use only source-backed syntax and the host services whose contract you have been given.
• Record a normal case and a boundary or unavailable-resource case.
• Label hand predictions separately from anything actually measured in a supplied toolchain.

Syntax colors are a reading aid, not a compiler. The line you are editing stays uncolored until you move to a different line; capitalization is never changed. Drafts stay on this browser and code is not executed.

import tmp;
const cache = tmp.create({
    name: "report-cache",
    storage: "ssd",
    maxSize: "2GB",
    lifetime: { duration: "30m", refreshOnAccess: true },
    cleanup: { automatic: true, onCrashRecovery: true }
});

PART V

Self-check

Use this check to notice what to revisit. It does not award a private course grade, block another page or claim to verify compiled code. Every answer has a learning explanation.

You may keep exploring even if you are unsure. Use the hint, compare the trace, and revise your explanation.

PART VI

Recap & small task

Bring the idea back to the mod feature you are building. A useful recap connects the mechanism to a decision you can make in your own code.

• Trace independent task and cleanup outcomes
• Explain the decision for the supplied case, then independently work the changed fixture.
• Separate source-backed behavior, host requirements and untested predictions.

One small recap task

In one or two sentences, name the decisive rule in “Trace independent task and cleanup outcomes” and predict the outcome of one changed input from your independent fixture. State which host behavior still needs real verification.

This marks your personal practice record only. It is not a certification or an official workspace assessment.