@hediet/debug-visualizer-data-extraction

A library that helps implementing data extractors for the Debug Visualizer VS Code extension. It will automatically be injected by the extension when the debugger attaches. Compatible with NodeJS and browsers.

Installation

Use the following command to install the library using yarn:

yarn add @hediet/debug-visualizer-data-extraction

Usage

createGraphFromPointers Helper

import { createGraphFromPointers } from "@hediet/debug-visualizer-data-extraction";

setTimeout(() => {
	new Main().run();
}, 0);

class Main {
	run() {
		const list = new DoublyLinkedList("1");
		list.setNext(new DoublyLinkedList("2"));
		list.next!.setNext(new DoublyLinkedList("3"));
		list.next!.next!.setNext(new DoublyLinkedList("4"));

		// Watch `visualize()` with the Debug Visualizer Extension for VS Code!
		const visualize = () =>
			// Returns `CommonDataTypes.Graph` data which can be visualized by
			// either the vis.js or the graphviz visualizer.
			createGraphFromPointers({ list, last, cur }, i => ({
				id: i.id,
				label: i.name,
				color: finished.has(i) ? "lime" : undefined,
				edges: [
					{ to: i.next!, label: "next" },
					{ to: i.prev!, label: "prev", color: "lightgray" },
				].filter(r => !!r.to),
			}));

		const finished = new Set();
		var cur: DoublyLinkedList | undefined = list;
		// Reverses `list`. Finished nodes have correct pointers,
		// their next node is also finished.
		var last: DoublyLinkedList | undefined = undefined;
		while (cur) {
			cur.prev = cur.next;
			cur.next = last;
			finished.add(cur);
			last = cur;
			cur = cur.prev;
		}
		console.log("finished");
	}
}

let id = 0;
class DoublyLinkedList {
	public readonly id = (id++).toString();
	constructor(public name: string) {}

	next: DoublyLinkedList | undefined;
	prev: DoublyLinkedList | undefined;

	public setNext(val: DoublyLinkedList): void {
		val.prev = this;
		this.next = val;
	}
}

Registering Custom Data Extractors

import { getDataExtractorApi } from "@hediet/debug-visualizer-data-extraction";

getDataExtractorApi().registerExtractor({
	id: "my-foo-extractor",
	getExtractions: (data, collector) => {
		if (data instanceof Foo) {
			collector.addExtraction({
				id: "my-foo-extraction",
				name: "My Foo Extraction",
				priority: 2000,
				extractData: () => ({ kind: { text: true }, text: "Foo" }),
			});
		}
	},
});

setTimeout(() => {
	new Main().run();
}, 0);

class Foo {}

class Main {
	run() {
		const f = new Foo();
		// if `f` is watched by the Debug Visualizer,
		// `my-foo-extractor` will provide the data for the visualizers.
		// See `CommonDataTypes` for data types that have built in visualizers.
		debugger;
	}
}