Skip to content

Instantly share code, notes, and snippets.

@webstrand
webstrand / 0-usage.ts
Created June 29, 2024 03:41
Tagged template literal unindenter. It's caches the intermediate unindented segments.
import { dedent } from "./dedent.ts"
for(let i = 0; i < 10; i++) {
console.log(dedent`
Hello, World!
this block of text gets unindented
interpolation works: ${i}
enjoy!
```)
}
type RFC9457ProblemOccurrence = {
/**
* A string containing a URI reference that identifies the problem type.
*
* Consumers MUST use this URI (after resolution, if necessary) as the problem type's
* primary identifier.
*
* When this member is not present, its value is assumed to be "about:blank".
*
* If the URI is a locator (e.g., those with an "http" or "https" scheme),
import { useCallback, Reducer, Dispatch, useState, useMemo, useEffect, useRef } from 'react';
type Batch<S, A extends object> = {
state: S,
actions: A[],
next: Batch<S, A> | null
}
class StreamReducer<S, A extends object> {
/**
@webstrand
webstrand / dev-mongodb.sh
Last active May 18, 2024 23:42
Create a mongodb replication-set for use with Prisma
mkdir -p dev.mongodb/{0,1,2}; rm -f dev.mongodb/{0,1,2}/log.*;
(
for i in {1..100}; do
socat -u OPEN:/dev/null UNIX-CONNECT:./dev.mongodb/0/.sock 2>/dev/null && break;
sleep 0.1;
done;
exec mongosh 'mongodb://.%2Fdev.mongodb%2F0%2F.sock' --eval "$(cat << EOF
const reinitiate = (() => {
@webstrand
webstrand / nginx.conf
Created May 10, 2024 14:31
Portable nginx reverse proxy with CORS override
#!/usr/bin/env -S nginx -e /dev/stderr -p . -c
# Run an NGINX instance serving the current directory on ports 8080 and 8443
# (when configured). Execute one of the following commands in the terminal.
# - start-nodaemon: ./nginx.conf -g 'daemon off;'
# - start: ./nginx.conf
# - stop: ./nginx.conf -s stop
# - reload: ./nginx.conf -s reload
pid .nginx/nginx.pid;
events {}
@webstrand
webstrand / instanceofvtag.js
Last active April 18, 2024 18:11
Comparing the performance of instanceof against tags
const Benchmark = require('benchmark');
const suite = new Benchmark.Suite;
class Base {
type = "base"
}
class Child extends Base {
type = "child"
}
@webstrand
webstrand / usernetnsenter.c
Last active March 8, 2024 14:41
SUID binary allowing unpriviliged users to enter permitted network namespaces
#define _GNU_SOURCE
#include <stdio.h>
#include <sched.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdint.h>
#include <inttypes.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
type If = {
kind: 'if'
condition: Expression
then: Expression
else: Expression
}
type Literal = {
kind: 'boolean'
value: boolean
@webstrand
webstrand / json-string-parser.ts
Created December 11, 2023 19:56
JSON string parser that generates minimal garbage by avoiding regex match objects
function parseString(json: string, startIndex: number) {
const Text = /[^\\"]+/y;
const Escapes = /\\+/y;
const Unicode = /[\dA-Fa-f]{4}/y;
let result = "";
for(let textStart = Text.lastIndex = startIndex;;) {
// Scan forward from the lastIndex until we encounter:
// 1. closing quote
// 3. end-of-string
@webstrand
webstrand / proxy-multi-inheritance.ts
Created November 22, 2023 15:20
Using Proxy and extensive abuse of #private we implement multiple inheritance in typescript
function Multi<Left extends new (...args: any[]) => object, Right extends new (...args: any[]) => object, Largs extends any[], Rargs extends any[], Linst extends object, Rinst extends object>(Left: Left & (new (...args: Largs) => Linst), Right: Right & (new (...args: Rargs) => Rinst)): {
new (largs: Largs, rargs: Rargs): Linst & Rinst
} & { [P in keyof Left]: Left[P] } & { [P in keyof Right]: Right[P] } {
let proxy;
class Multi extends (Left as any) {
#bastard: Rinst;
constructor(largs: Largs, rargs: Rargs) {