Write the utility acceptance contract — Discover and trace

PART I

Warm-up

Reconnect with a useful idea before starting write the utility acceptance contract. 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

Turn “a useful team utility” into a measurable promise

An acceptance contract makes a feature claim falsifiable. A feature description becomes reviewable when it names supplied inputs, required effects, visible outcomes and failure boundaries. Separate what source vocabulary expresses, what an exercise host must guarantee, and what a paper trace merely predicts. Public practice can be completed manually; it does not certify code execution.

Brief: a team utility lets an editor prepare a support request, preview it, and submit it to team A. Drafts contain title and body. Observers may preview but may not submit. No host APIs are yet supplied.

For each requirement, choose an ordinary case and a case that would expose a plausible wrong implementation. Name the expected artifact or state change and the evidence that would establish it. A list of attractive screens is not a substitute for observable behavior. Worked case: A reviewable promise is: given a nonempty title/body and current editor grant, submit requests one team-A queue operation; show Queued only after confirmation. Preview is a separate read-only action. These are host requirements and predictions, not executed behavior.

Compare the tempting alternative: “Works for the team” cannot distinguish a valid preview from an unauthorized submit and provides no point at which completion is justified.

Worked reasoning and supplied artifact

// Paper trace / supplied exercise-host contract; no execution claimed.
// Brief: a team utility lets an editor prepare a support request, preview it, and submit it to team A. Drafts contain title and body. Observers may preview but may not submit. No host APIs are yet supplied.
// A reviewable promise is: given a nonempty title/body and current editor grant, submit requests one team-A queue operation; show Queued only after confirmation. Preview is a separate read-only action. These are host requirements and predictions, not executed behavior.

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: Event-driven team utility. Build a small, understandable change around write the utility acceptance contract.

Write three requirements for preview, submission and denial. Each must name input, permission, effect and visible result.

What to produce

A three-row acceptance contract with explicit no-runtime status.

• 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 wuix.widget;
import app;
domain Workspace {
    const application = Application({
        name: "Workspace",
        window: { title: "Dashboard", size: [1280, 800] },
        events: {
            "app.ready": fnc() -> void { console.log("Ready"); }
        }
    });
}

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.

• Turn “a useful team utility” into a measurable promise
• Write three requirements for preview, submission and denial. Each must name input, permission, effect and visible result.
• Separate source-backed behavior, host requirements and untested predictions.

One small recap task

Replace one vague adjective in the brief with a concrete condition.

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