Vue’s reactivity system wraps objects in Proxies to track property access and mutation. This is the mechanism that makes the UI reactive, but it is also a mechanism that some objects cannot tolerate. A third-party library instance that performs identity checks, a DOM node that the browser expects to be the exact object it created,…
Vue’s default reactivity is deep. A ref({ nested: { count: 1 } }) wraps every nested object in a Proxy, so mutating nested.count triggers a re-render. This is convenient, but it is also expensive for large data structures, external library instances, and immutable API responses that will never be mutated internally. shallowRef() and shallowReactive() provide…
Vue’s customRef is the escape hatch for creating a ref whose dependency tracking and update triggering are under explicit programmer control. A standard ref calls track() when read and trigger() when written, with no opportunity to intervene. customRef receives those two functions as arguments and returns a get/set pair, allowing the implementation to decide when…
Vue’s reactivity system exposes a small set of utility functions for inspecting and normalizing reactive values. These functions are not the ones application code uses most often—ref, computed, and reactive are—but they are the ones composables and libraries use to handle arguments that might be a raw value, a ref, or a reactive object. The…
A quick-reference for SQL syntax, functions, and behavior across PostgreSQL, MySQL, and SQL Server. Organized for lookup, not for reading. SELECT Clause Order Clause Purpose Evaluated SELECT Columns to return 5th FROM Tables to query 1st JOIN Combine tables 2nd WHERE Filter rows 3rd GROUP BY Group rows 4th HAVING Filter groups 6th ORDER BY…
A quick-reference for npm commands, configuration, and dependency resolution. Organized for lookup, not for reading. Core Commands Command Purpose npm init Create package.json interactively npm init -y Create with defaults npm install Install all dependencies npm install <pkg> Install and save to dependencies npm install <pkg>@<ver> Install specific version npm install -D <pkg> Install as…
Two fields in package.json control dependency resolution when the default behavior does not produce the tree the project needs. peerDependencies declares what a package expects its consumer to provide, and peerDependenciesMeta marks specific peers as optional. overrides forces a specific version of a package anywhere in the dependency tree, including transitive dependencies that the project…
Security in npm operates on two axes: the dependency tree and the credentials that authorize publishing. The dependency tree is audited with npm audit, which compares installed packages against a vulnerability database and offers automated fixes. The credentials are managed as access tokens, which have been consolidated into a single granular model as of November…
An npm workspace is a repository whose root package.json contains a workspaces field listing the directories that hold other package.json files. Running npm install at the root installs every workspace’s dependencies in one pass and symlinks the local packages into the root node_modules, so they can depend on each other without being published to a…
A scoped package is a package whose name is prefixed with a namespace, written as @scope/package-name. The scope is the part between the @ and the /, and it groups related packages under a single namespace. Scopes exist to prevent name collisions: a package named utils is unique, but @myorg/utils and @otherorg/utils can coexist because…