feat: add --expect-entries to npm query

This will allow users to tell npm whether or not to exit with an exit
code depending on if the command had any resulting entries or not, or a
specific number of entries.

lib/base-command.js

@@ -98,6 +98,28 @@ class BaseCommand {
     })
   }
 
+  // Compare the number of entries with what was expected
+  checkExpected (entries) {
+    const expected = this.npm.config.get('expect-entries')
+    if (expected === null) {
+      // By default we do nothing
+      return
+    }
+    if (typeof expected === 'number') {
+      if (entries !== expected) {
+        process.exitCode = 1
+      }
+      return
+    }
+    // entries is boolean
+    if (expected === true && !entries) {
+      process.exitCode = 1
+    } else if (expected === false && !!entries) {
+      process.exitCode = 1
+    }
+    // TODO `>5` or `<=6` which will require a custom Config type
+  }
+
   async execWorkspaces (args, filters) {
     throw Object.assign(new Error('This command does not support workspaces.'), {
       code: 'ENOWORKSPACES',

lib/commands/query.js

@@ -48,6 +48,7 @@ class Query extends BaseCommand {
     'workspace',
     'workspaces',
     'include-workspace-root',
+    'expect-entries',
   ]
 
   get parsedResponse () {
@@ -67,6 +68,7 @@ class Query extends BaseCommand {
     const items = await tree.querySelectorAll(args[0], this.npm.flatOptions)
     this.buildResponse(items)
 
+    this.checkExpected(this.#response.length)
     this.npm.output(this.parsedResponse)
   }
 
@@ -89,6 +91,7 @@ class Query extends BaseCommand {
       }
       this.buildResponse(items)
     }
+    this.checkExpected(this.#response.length)
     this.npm.output(this.parsedResponse)
   }
 

lib/utils/config/definitions.js

@@ -650,6 +650,16 @@ define('engine-strict', {
   flatten,
 })
 
+define('expect-entries', {
+  default: null,
+  type: [null, Boolean, Number],
+  description: `
+    Tells npm how many entries to expect from the command. Can be either
+    true (expect some entries), false (expect no entries), or a number to match
+    exactly.
+  `,
+})
+
 define('fetch-retries', {
   default: 2,
   type: Number,

tap-snapshots/test/lib/commands/config.js.test.cjs

@@ -48,6 +48,7 @@ exports[`test/lib/commands/config.js TAP config list --json > output matches sna
   "dry-run": false,
   "editor": "{EDITOR}",
   "engine-strict": false,
+  "expect-entries": null,
   "fetch-retries": 2,
   "fetch-retry-factor": 10,
   "fetch-retry-maxtimeout": 60000,
@@ -201,6 +202,7 @@ diff-unified = 3
 dry-run = false 
 editor = "{EDITOR}" 
 engine-strict = false 
+expect-entries = null 
 fetch-retries = 2 
 fetch-retry-factor = 10 
 fetch-retry-maxtimeout = 60000 

tap-snapshots/test/lib/docs.js.test.cjs

@@ -891,6 +891,15 @@ Node.js version.
 
 This can be overridden by setting the \`--force\` flag.
 
+#### \`expect-entries\`
+
+* Default: null
+* Type: null, Boolean, or Number
+
+Tells npm how many entries to expect from the command. Can be either true
+(expect some entries), false (expect no entries), or a number to match
+exactly.
+
 #### \`fetch-retries\`
 
 * Default: 2
@@ -2150,6 +2159,7 @@ Array [
   "dry-run",
   "editor",
   "engine-strict",
+  "expect-entries",
   "fetch-retries",
   "fetch-retry-factor",
   "fetch-retry-maxtimeout",
@@ -2389,6 +2399,7 @@ Array [
 
 exports[`test/lib/docs.js TAP config > keys that are not flattened 1`] = `
 Array [
+  "expect-entries",
   "init-author-email",
   "init-author-name",
   "init-author-url",
@@ -3730,6 +3741,7 @@ Options:
 [-g|--global]
 [-w|--workspace <workspace-name> [-w|--workspace <workspace-name> ...]]
 [-ws|--workspaces] [--include-workspace-root]
+[--no-expect-entries|--expect-entries <expect-entries>]
 
 Run "npm help query" for more info
 
@@ -3741,6 +3753,7 @@ npm query <selector>
 #### \`workspace\`
 #### \`workspaces\`
 #### \`include-workspace-root\`
+#### \`expect-entries\`
 `
 
 exports[`test/lib/docs.js TAP usage rebuild > must match snapshot 1`] = `

test/lib/commands/query.js

@@ -68,6 +68,7 @@ t.test('recursive tree', async t => {
   await npm.exec('query', ['*'])
   t.matchSnapshot(joinedOutput(), 'should return everything in the tree, accounting for recursion')
 })
+
 t.test('workspace query', async t => {
   const { npm, joinedOutput } = await loadMockNpm(t, {
     config: {
@@ -197,3 +198,72 @@ t.test('global', async t => {
   await npm.exec('query', ['[name=lorem]'])
   t.matchSnapshot(joinedOutput(), 'should return global package')
 })
+
+t.test('expect entries', t => {
+  const { exitCode } = process
+  t.afterEach(() => process.exitCode = exitCode)
+  const prefixDir = {
+    node_modules: {
+      a: { name: 'a', version: '1.0.0' },
+    },
+    'package.json': JSON.stringify({
+      name: 'project',
+      dependencies: { a: '^1.0.0' },
+    }),
+  }
+  t.test('false, has entries', async t => {
+    const { npm, joinedOutput } = await loadMockNpm(t, {
+      prefixDir,
+    })
+    npm.config.set('expect-entries', false)
+    await npm.exec('query', ['#a'])
+    t.not(joinedOutput(), '[]', 'has entries')
+    t.ok(process.exitCode, 'exits with code')
+  })
+  t.test('false, no entries', async t => {
+    const { npm, joinedOutput } = await loadMockNpm(t, {
+      prefixDir,
+    })
+    npm.config.set('expect-entries', false)
+    await npm.exec('query', ['#b'])
+    t.equal(joinedOutput(), '[]', 'does not have entries')
+    t.notOk(process.exitCode, 'exits without code')
+  })
+  t.test('true, has entries', async t => {
+    const { npm, joinedOutput } = await loadMockNpm(t, {
+      prefixDir,
+    })
+    npm.config.set('expect-entries', true)
+    await npm.exec('query', ['#a'])
+    t.not(joinedOutput(), '[]', 'has entries')
+    t.notOk(process.exitCode, 'exits without code')
+  })
+  t.test('true, no entries', async t => {
+    const { npm, joinedOutput } = await loadMockNpm(t, {
+      prefixDir,
+    })
+    npm.config.set('expect-entries', true)
+    await npm.exec('query', ['#b'])
+    t.equal(joinedOutput(), '[]', 'does not have entries')
+    t.ok(process.exitCode, 'exits with code')
+  })
+  t.test('number, matches', async t => {
+    const { npm, joinedOutput } = await loadMockNpm(t, {
+      prefixDir,
+    })
+    npm.config.set('expect-entries', 1)
+    await npm.exec('query', ['#a'])
+    t.not(joinedOutput(), '[]', 'has entries')
+    t.notOk(process.exitCode, 'exits without code')
+  })
+  t.test('number, does not match', async t => {
+    const { npm, joinedOutput } = await loadMockNpm(t, {
+      prefixDir,
+    })
+    npm.config.set('expect-entries', 1)
+    await npm.exec('query', ['#b'])
+    t.equal(joinedOutput(), '[]', 'does not have entries')
+    t.ok(process.exitCode, 'exits with code')
+  })
+  t.end()
+})