Reduce Noise in Run Analytics Events

[DNR500]

Summary

Issue 1543.

Investigation into duplicate Project - Ran code and Project - Run completed analytics events. I was unable to reproduce the kind of event timings reported in the ticket through normal UI interaction alone. The closest match came from running the following in the browser console on a project page:

let n = 0;
const burst = setInterval(() => {
  document.querySelector("editor-wc")?.runCode();
  if (++n >= 15) clearInterval(burst);
}, 50);

This PR takes a two-pronged approach: fix several edge cases in how run events are dispatched, and add gating so analytics only records runs that are likely to be meaningful. Should provide some fortification against abuse of the run button and over running the code.

Bug fixes

Briefly — see commit messages for detail:

• Fire runCompleted once per run cycle, not again when error state updates after the run ends.
• Remove leaked window.message listeners in HtmlRunner that could cause duplicate handling on re-render.
• Keep runStarted stable across web-component remounts during an active run.

Run event dispatch gating

Commits have been used break this down a little

Code-change snapshot (editable projects)

Run analytics events (editor-runStarted / editor-runCompleted) are only dispatched when the project's code differs from the last counted run. Repeated runs of unchanged code are suppressed.

This assumes that a user hammering the run button without changing code does not tell us anything useful for analytics — as these do not reflect a new attempt or progress.

Read-only mode (e.g. a teacher viewing student work) bypasses the snapshot check so deliberate re-runs of the same code are still tracked.

Debounce (250ms quiet period)

A trailing debounce is also applied so bursts of run attempts collapse into a single counted dispatch after 250ms of quiet. This reduces noise on project views where code cannot be edited, or where a code-change snapshot is not practical (e.g. Scratch green-flag runs via ScratchContainer).

Together, snapshot gating handles the common student case; debounce handles read-only and Scratch paths where repeated runs without an easy code-diff are still possible.

[Copilot]

Pull request overview

Reduces duplicate/noisy run analytics events in the web component editor by tightening run lifecycle dispatch (start/completed) and adding gating (code snapshot + debounce) to suppress repeated “meaningless” runs.

Changes:

• Adds a debounced run-event cycle with optional per-run code snapshot gating to suppress repeated runs of unchanged code.
• Makes runStarted/runCompleted emission more robust across rerenders/remounts and post-run error-state updates.
• Fixes duplicate handling by ensuring HtmlRunner cleans up window.message listeners; adds/updates unit tests to cover new behavior.

Reviewed changes

Copilot reviewed 13 out of 13 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/web-component.js	Resets module-level run-event tracking state when the web component disconnects.
src/components/WebComponentProject/WebComponentProject.jsx	Routes runStarted/runCompleted dispatch through new debounced + snapshot-gated run-cycle helpers.
src/components/WebComponentProject/WebComponentProject.test.js	Updates/extends tests to account for debounced run-event dispatch and snapshot gating.
src/components/WebComponentProject/runEventTrackingState.js	Introduces module-level tracking for previous codeRunTriggered and project sync/reset behavior.
src/components/WebComponentProject/runEventTrackingState.test.js	Adds unit coverage for the new tracking-state module behavior.
src/components/WebComponentProject/runEventCodeSnapshot.js	Implements debounce + “code changed since last counted run” snapshot gating for run events.
src/components/WebComponentProject/runEventCodeSnapshot.test.js	Adds unit tests for debounce/snapshot gating behaviors and edge cases.
src/components/WebComponentProject/buildProjectCodeSnapshot.js	Adds stable snapshot builder for project components to support gating.
src/components/WebComponentProject/buildProjectCodeSnapshot.test.js	Adds unit tests ensuring snapshot stability and change detection.
src/components/Editor/Runners/HtmlRunner/HtmlRunner.jsx	Reworks iframe message handling to avoid leaked listeners and duplicate handling across rerenders/unmounts.
src/components/Editor/Runners/HtmlRunner/HtmlRunner.test.js	Adds tests asserting messages aren’t handled after unmount and aren’t duplicated after remount.
src/components/Editor/Project/ScratchContainer.jsx	Debounces scratch runStarted analytics dispatch via the shared run-event cycle helper.
src/components/Editor/Project/ScratchContainer.test.js	Updates tests to account for debounced scratch runStarted dispatch (including burst collapsing).

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