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@vltpkg/query

query

The vlt query syntax engine.

Usage · Examples · Supported Syntax Reference

Usage

import { Query } from '@vltpkg/query'


const query = new Query({ nodes })
query.search(':root > *')

Examples

Querying nodes from a local node_modules folder.

import { actual } from '@vltpkg/graph'
import { Query } from '@vltpkg/query'


const graph = await actual.load({ projectRoot: process.cwd() })
const query = new Query([...graph.nodes.values()])
query.search(':root > *')

Supported Syntax Reference

The vlt query syntax enable usage of css-selector-like strings to filter packages.

Many of the common elements of the CSS language are available, notably:

  • * Universal selector, matches all selected items.
  • & Nesting selector, allows for nesting selectors.
  • {} Curly braces, when querying can be used to nest selectors.

Split by group of selectors below is the complete reference to supported elements.

Attribute selectors

Attribute selectors are used to match a value found in the package.json metadata for each of the nodes being queried to a arbitrary value you choose.

  • [attr] Matches elements with an attr property in its package.json.
  • [attr=value] Matches elements with a property attr whose value is exactly value.
  • [attr^=value] Matches elements with a property attr whose value starts with value.
  • [attr$=value] Matches elements with a property attr whose value ends with value.
  • [attr~=value] Matches elements with a property attr whose value is a whitespace-separated list of words, one of which is exactly value.
  • [attr|=value] Matches elements with a property attr whose value is either value or starts with value-.
  • [attr*=value] Matches elements with a property attr.
  • [attr=value i] Case-insensitive flag, setting it will cause any comparison to be case-insensitive.
  • [attr=value s] Case-sensitive flag, setting it will cause comparisons to be case-sensitive, this is the default behavior.

Class selectors

  • .prod Matches prod dependencies to your current project.
  • .dev Matches packages that are only used as dev dependencies in your current project.
  • .optional Matches packages that are optional to your current project.
  • .peer Matches peer dependencies to your current project.
  • .workspace Matches the current project worksacpes (listed in your vlt-workspaces.json file).

Combinators

  • > Child combinator, matches packages that are direct dependencies of the previously selected nodes.
  • Descendant combinator, matches all packages that are direct & transitive dependencies of the previously selected nodes.
  • ~ Sibling combinator, matches packages that are direct dependencies of all dependents of the previously selected nodes.

ID Selectors

Identifiers are a shortcut to retrieving packages by name, unfortunately this shortcut only works for unscoped packages, with that in mind it’s advised to rely on using Attribute selectors (showed above) instead.

e.g: #foo is the same as [name=foo]

Pseudo class selectors

  • :attr(key, [attr=value]) The attribute pseudo-class allows for selecting packages based on nested properties of its package.json metadata. As an example, here is a query that filters only packages that declares an optional peer dependency named foo: :attr(peerDependenciesMeta, foo, [optional=true])
  • :empty Matches packages that have no dependencies installed.
  • :has(<selector-list>) Matches only packages that have valid results for the selector expression used. As an example, here is a query that matches all packages that have a peer dependency on react: :has(.peer[name=react])
  • :is(<forgiving-selector-list>) Useful for writing large selectors in a more compact form, the :is() pseudo-class takes a selector list as its arguments and selects any element that can be selected by one of the selectors in that list. As an example, let’s say I want to select packages named a & b that are direct dependencies of my project root: :root > [name=a], :root > [name=b] using the :is() pseudo-class, that same expression can be shortened to: :root > :is([name=a], [name=b]). Similar to the css pseudo-class of the same name, this selector has a forgiving behavior regarding its nested selector list ignoring any usage of non-existing ids, classes, combinators, operators and pseudo-selectors.
  • :not(<selector-list>) Negation pseudo-class, select packages that do not match a list of selectors.
  • :private Matches packages that have the property private set on their package.json file.
  • :type(registry|file|git|remote|workspace) Matches packages based on their type, e.g, to retrieve all git dependencies: :type(git).

Pseudo Elements

  • :project Returns both the root node (as defined below) along with any workspace declared in your project.
  • :root Returns the root node, that represents the package defined at the top-level package.json of your project folder.
  • :scope Returns the current scope of a given selector