Tags
#php
#kotlin
#bash
#go
#sql
#rust
#typescript
#html
#java
#python
#files
#utils
#strings
#http
#concurrency
#async
#json
#arrays
#security
#types
#crypto
#database
#dates
#format
Bash
Find Commit That Introduced a String
`git log -S` (the "pickaxe") finds commits whose diff added or removed a given string. The fastest way to answer "when did this line first appear?"
@admin
Go
http.Client with Timeout
`http.DefaultClient` has no timeout — a hung server can hang your whole program forever. ALWAYS use a custom client with an explicit timeout for outbound requests.
Go
Atomic File Write (temp + rename)
Write to a temp file in the SAME directory, then `os.Rename` to the final name. Rename is atomic on POSIX — readers never see a half-written file.
Java
Custom Exception Hierarchy
For library/service code, define a small exception hierarchy rooted at a common base class. Callers can catch the base type or specific subclasses; you can add fields for structured context.
HTML
Native <dialog> Modal
The HTML `<dialog>` element gives you a real modal — focus trap, Escape-to-close, backdrop overlay — without any JS library. Method `.showModal()` opens; `.close()` closes.
Kotlin
Ktor Client — GET Request
Ktor is JetBrains' Kotlin-first HTTP client. Multiplatform (JVM, JS, Native). Coroutine-native — every call is a suspend function.
Rust
Atomic File Write (tempfile + persist)
Write to a temp file in the SAME directory, then atomically `persist` (rename). The `tempfile` crate handles cleanup if you crash before persisting.
Bash
Memory / CPU / Load Quick Check
One-liners for the three most-requested system metrics. Use in monitoring scripts or as ad-hoc sanity checks.
Go
context.Context — Cancellation & Deadlines
`context.Context` propagates deadlines, cancellation, and request-scoped values down a call chain. EVERY blocking / long-running function should take a `ctx context.Context` as its first parameter.
Kotlin
Coroutine Testing with runTest
`runTest { }` from kotlinx-coroutines-test gives you a virtual time scheduler — `delay(1000)` finishes instantly while preserving ordering. No more flaky 1-second test sleeps.
PHP
Discord Webhook Notification
Same idea as Slack but for Discord webhooks — supports rich embeds with a title, description, and color. Useful for dev/ops dashboards or bot integrations.
SQL
Window Function vs N+1 Query
Don't fetch a list, then loop in code to count each parent's children. Use a window function or a single GROUP BY — turn 1,001 queries into 1.
TypeScript
Deep Clone with structuredClone
Forget JSON.parse(JSON.stringify(...)) — modern runtimes (Node 17+, all current browsers) ship structuredClone, which handles Dates, Maps, Sets, typed arrays, and cycles correctly.
JavaScript
Chunk Array
Splits an array into smaller arrays (chunks) of a specified size. The last chunk may be smaller if the array length is not evenly divisible. Useful for batch processing, pagination, rendering large lists in chunks, and rate-limited API calls.
JavaScript
Async Sleep / Delay
Returns a Promise that resolves after a given number of milliseconds. Use with await to pause async functions without blocking the main thread. More readable than nested setTimeout callbacks and composable with other async utilities.
JavaScript
Group Array by Key
Groups an array of objects into a map keyed by the result of a callback or property name. Uses Object.groupBy when available (ES2024) and falls back to a reduce implementation. Returns an object whose keys are the group names and values are arrays of matching items.
SQL
UPSERT — PostgreSQL ON CONFLICT
`INSERT ... ON CONFLICT DO UPDATE` inserts a row, or updates the existing one if a unique-constraint collision happens. The atomic alternative to "SELECT, then INSERT or UPDATE".