Docs / Reference

The words JSpark uses

Snippet, Run, Step, Kind and the rest, each in one line.

On this page

Writing code
Running code
The Timeline
Keeping code
Editions

JSpark uses a small set of words, always in the same sense and with the same capitals, in the app and in these docs. Each term links to the page that says more.

Writing code

Snippet: A piece of JavaScript or TypeScript you write and run. Each tab holds one.
Starter: A way to begin a Snippet, such as Node.js, Web Page or React. It opens with a small demo that runs.
Home screen: What the window shows when no Snippet is open: the Starters.
Kind: Where a Snippet runs: Node, a Web page beside the editor, or a Vue or Svelte component. It is set when the Snippet is made.
Part: One of the three parts of a Web Snippet’s page: markup, style and script. The editor shows one at a time.
server Part JSpark+: Node code that a page carries beside it, and reaches with fetch on its own origin.
Language: JavaScript or TypeScript. JavaScript runs as JavaScript; TypeScript is also type-checked.
Load Mode: How Node loads a Snippet: Module (ESM), with import, or Script (CommonJS), with require.
Peek: A //? comment that shows a value beside the line after the Run. It is drawn, never written into the Snippet.

Running code

Run: One execution of a Snippet, from start to finish. It completes, throws, is stopped, or does not run at all.
Run as you type: Starting a Run a moment after you stop typing, instead of when you press Run. Also called Auto-run.
Outside Access: Code that reaches your files, the network, other programs or the process. It keeps a Snippet out of Run as you type.
Held Run: A Run that prints the type errors instead of running, because “Don’t run with type errors” is on.
Stale Result: Output from before your last edit. It stays on screen, marked, until the next Run.
Page: What a Web Snippet builds: a real page in a real browser, beside the editor.
Working Folder: The folder a Node Run works in. A file written to a relative path lands there.

The Timeline

Timeline: The window replaying a recorded Run, one Step at a time. The editor is read-only while it is open.
Step Run: A Run that records as it goes, so it can be replayed. Opening the Timeline starts one.
Trace: The recording a Step Run makes: every Step, in the order the code reached them.
Step: One moment in a Trace: one statement, and the values at that moment. A line can hold several Steps.
Step detail: How much a recording keeps: Lines, one Step per statement, or Inside lines, which also records each call, callback and loop check.
Inside lines JSpark+: The Step detail that records Inner Steps, with what each came to, such as i < 3 → true.
Scrubbing: Moving backwards and forwards through a Trace. Nothing runs again: the code has already run.
Autoplay: Moving forward through the Steps by itself, at a speed you choose.
Variables: The names in scope at the Step, with their values, grouped by scope, such as everywhere, in counter() or in this loop.
Remembered: A name a closure still reads from a function further out, such as the n of a call that has returned.
Hover Value: A name’s value at the Step on screen, shown where you point. Never a value from a later Step.
Truncated Trace: A Trace that stopped recording before the Run finished, because it hit a limit. The Steps it has still work.

Keeping code

Library: Every Saved Snippet, in a window of its own.
Saved Snippet: A copy of a Snippet you kept on purpose, with a title, an optional description and Tags. It stays after the tab closes.
Tag: A word a Saved Snippet is filed under: lowercase letters, digits and hyphens. Picking two narrows the list.
Starter Tag: The Tag of the Starter a Saved Snippet began from, such as nodejs or react. It can’t be edited or removed.
Library Export: One .json file with every Saved Snippet, made by Export Library….

Editions

Edition: What the app allows on this device: JSpark or JSpark+. It is the same app and the same download.
JSpark: The free edition. It is not a trial, and it doesn’t expire.
JSpark+: The paid edition, which lifts the free edition’s limits. A License Key unlocks it in place.
License Key: What you receive when you buy JSpark+. It is for one person, on up to three devices.
Activation: A License Key’s place on one device. Deactivating a device frees its place for another.
Yearly and Lifetime: The two plans. Yearly is JSpark+ while it renews, and JSpark once it lapses, with your work kept. Lifetime never lapses.