[query] need a descendant operator that can specify type

[lukekarrys]

Problem Statement

In the npm/cli repo the following query should return an empty set since none of the direct dependents are .dev deps:

npm query ':root > #npm-package-arg.dev'
# should also apply to this
node . query ':root > .dev > #npm-package-arg'

Current Behavior

In the current implementation both :root and .dev are collected separately so it returns:

[
  {
    "name": "npm-package-arg",
    "version": "10.1.0",
    "location": "node_modules/npm-package-arg",
    "path": "/Users/lukekarrys/projects/npm/cli/node_modules/npm-package-arg",
    "from": [
      "node_modules/init-package-json",
      "node_modules/npm-pick-manifest",
      "node_modules/npm-registry-fetch",
      "node_modules/pacote",
      "node_modules/@npmcli/template-oss",
      "mock-registry",
      "workspaces/libnpmexec",
      "workspaces/libnpmaccess",
      "workspaces/libnpmdiff",
      "workspaces/libnpmpack",
      "workspaces/libnpmpublish",
      "workspaces/arborist",
      ""
    ],
    "to": [
      "node_modules/hosted-git-info",
      "node_modules/proc-log",
      "node_modules/semver",
      "node_modules/validate-npm-package-name"
    ],
    "dev": false,
    "inBundle": true,
    "deduped": false,
    "overridden": false,
    "queryContext": {}
  }
]

Expected Behavior

It should return [] since npm-package-arg is only a direct .prod dependency

[wraithgar]

This seems like a docs/education issue. .dev does not mean "In the devDependencies of something in the current set" it means "It is in the tree because of something in the root's devDependencies"

It seems what you are trying to query is all of the entries in devDependencies?

[wraithgar]

there's some improvement to be made for the .dev selector in general i think. we don't have a way to get only direct devDependencies and we also don't have a way to get every node that exists exclusively as a devdep

[wraithgar]

What we really need is a descendant operator to allow us to specify the edges out types. root > :dep(dev) would be everything in the root package's devDependencies for example