TIL - Today I learned
Bash
- A preceding space prevents dangerous commands from going into history
- How to add interactive questions to bash scripts
- How to automatically respond to confirmations in CLI tools
- [ is an actual bash command
- Write data to files and pipe it into other programs the same time
- The power of cat and stdin
- Process substitution in bash
- Powerful history command shortcuts in bash
CSS
- color-adjust trumps user agent setting about background printing
- Stylesheets do not only block rendering but also JavaScript execution
- The CSS attribute selector has a case-insensitive mode
- SVGs have additional pointer-events properties
- CSS grid will soon be the shortest way to center elements
- Viewport units for font sizes destroy zooming
- Overflow ellipsis after x lines
- Labels trigger states for associated inputs
- Interaction media queries in CSS
- A use case for CSS min-content and max-content
- Useful background-repeat options other than repeat
JavaScript
- You can configure the logged error stack trace length in certain environments
- Stylesheets do not only block rendering but also JavaScript execution
- Property order is predictable in JavaScript objects since ES2015
- Element.prototype.matches can be used to check if an element includes a certain class
- +-0, NaN and Object.is in JavaScript
- lookaheads (and lookbehinds) in JavaScript regular expressions
- You can't set new properties on JavaScript Symbols
- How the rest operator and default values affect the function length property
- The global `Reflect` object, its use cases and things to watch out for
- Not every JavaScript function is constructable
- How to quickly perform a syntax check of a JavaScript file
- Measuring execution time more precisely in the Browser and Node.js
- Await in async functions works for any thenable
- isNaN is not equal Number.isNaN
- includes really is the better indexOf
- localeCompare helps to compare strings in a sane manner
- IntersectionObserver accepts several threshold values
- There is a Unicode mode in JavaScript regular expressions
- Equality of object property names depends on code units
- The dot in RegExp doesn't match all characters in JavaScript
- Proper Tail Calls (PTC) in JavaScript
- Implicit form submission doesn't work always
- String.prototype.normalize for safer string comparison
- Conditional properties with object spread
- Completion values in JavaScript
- var let = 12 is valid JavaScript
- finally in a try/catch statements really goes over everything
- Skipped holes in JavaScript Arrays
- Interfere Constructor calls with ES6 Proxies
Node.js
- The NPM_CONFIG_PRODUCTION flag sets the NOVE_ENV variable to production in npm scripts
- You can pipe into Node.js
- Node.js sends warnings when you add too many listeners to an event emitter
- How to figure out the Node.js entry script with process.mainModule or require.main
- How to quickly perform a syntax check of a JavaScript file
- Measuring execution time more precisely in the Browser and Node.js
- Commands in the Node.js REPL
- console.dir() is short for console.log( util.inspect() )