Bash

URL-Encode and URL-Decode

Encode and decode URL-safe strings entirely in bash — no python or external tool required. Useful in pure-shell deployment scripts that need to build query strings.

Jun 13, 2026 0

Kotlin

associate and associateBy

`associateBy` builds a `Map<K, T>` keyed by a derived value. `associateWith` keys by the items themselves with derived values. `associate` lets you build both key and value from each item.

Jun 13, 2026 0

Kotlin

Type-Safe Builder DSL

`@DslMarker` + lambdas with receivers let you build statically-typed DSLs that look like declarative configuration. The HTML / Gradle Kotlin DSL style.

Jun 13, 2026 0

Go

slices package — Modern Helpers

`slices` (Go 1.21+) ships the iteration helpers everyone wrote by hand for years: Contains, Index, Sort, SortFunc, BinarySearch, Clone, Reverse, Equal, Max/Min.

Jun 13, 2026 0

Go

errors.Join — Aggregate Multiple Errors

Go 1.20+ ships `errors.Join`, which combines multiple errors into one. Stop accumulating errors in a slice and stringifying yourself — use the standard library.

Jun 13, 2026 0

Kotlin

Coroutine Cancellation

Cancellation is cooperative — your coroutine must check via `ensureActive()`, `yield()`, or any other suspending call. CPU-busy loops without a suspend point are NOT cancellable.

Jun 13, 2026 0

Kotlin

kotlin.test — Basic Tests

`kotlin.test` is the multiplatform test stdlib. `@Test` marks a test; `assertEquals`, `assertTrue`, `assertFailsWith` are the workhorses.

Jun 13, 2026 0

Bash

Word Frequency Count

Classic shell one-liner: split text into words, sort, count uniques, sort by count. Useful for log analysis, content audits, and tag-cloud-style summaries.

Jun 13, 2026 0

Kotlin

Ktor Server — JSON API with kotlinx.serialization

Install `ContentNegotiation` + `Json` plugin and you get typed (de)serialization for every route. Decode request bodies into data classes; respond with data classes.

Jun 13, 2026 0

TypeScript

useClickOutside — Detect Outside Clicks

Fire a callback when the user clicks anywhere outside a referenced element. Perfect for closing dropdowns, popovers, and modal-less menus.

Jun 13, 2026 0

Kotlin

minOf / maxOf / sumOf / averageOf

Numerical reducers with a selector lambda — much cleaner than `.map { ... }.max()` chains. `sumOf` is type-aware (returns Int, Long, Double, BigDecimal as appropriate).

Jun 13, 2026 0

Kotlin

Path Operations with java.nio.file

Modern Kotlin code uses `java.nio.file.Path` over the legacy `File`. Operator overloads + Kotlin extensions make it ergonomic.

Jun 13, 2026 0

Go

Static File Server

`http.FileServer` serves a directory; combine with `http.StripPrefix` to mount it at a URL path. One line for the most common static-asset use case.

Jun 13, 2026 0

TypeScript

usePrevious — Track Last Render's Value

Returns the value the prop/state had on the previous render. Useful for detecting transitions (e.g. "the count just went from 0 to 1") inside effects.

Jun 13, 2026 0

Kotlin

use { } — Auto-Close Resources

`use { }` calls `close()` on any `Closeable` (file, stream, JDBC connection, …) when the block exits — even on exception. Kotlin's try-with-resources.

Jun 13, 2026 0

Bash

List Listening Ports

`ss` is the modern netstat — faster, more readable, ships everywhere. Show only listening TCP ports with their owning process.

Jun 13, 2026 0

TypeScript

Sleep / Delay

The async/await-friendly version of `setTimeout`. The one-liner everyone re-invents — keep it in a util file. Optional AbortSignal lets you cancel mid-wait.

Jun 13, 2026 0

Rust

Read a File — Whole / Lines / Bytes

Three common patterns: load it all into memory, iterate line-by-line, or stream bytes. Pick by file size — `read_to_string` is convenient but bad for huge files.

Jun 13, 2026 0

Kotlin

MockK — Kotlin-Idiomatic Mocking

MockK plays well with Kotlin: final classes, coroutines, top-level functions, all mockable. `every { ... } returns ...` is the canonical setup.

Jun 12, 2026 0

JavaScript

IndexedDB Wrapper

A Promise-based wrapper for the IndexedDB API — simplifies the verbose request/onsuccess/onerror pattern into clean async/await calls. Supports get, set, delete, and getAll operations on a named object store. Ideal for storing large client-side datasets, offline data, and blobs that exceed localStorage limits.

Jun 12, 2026 0