fix: much clearer npx 'canceled' error (#6642)

Co-authored-by: AaronHamilton965 <91709196+AaronHamilton965@users.noreply.github.com>

test/lib/commands/exec.js

@@ -129,3 +129,38 @@ t.test('workspaces', async t => {
   const exists = await fs.stat(path.join(npm.prefix, 'workspace-a', 'npm-exec-test-success'))
   t.ok(exists.isFile(), 'bin ran, creating file inside workspace')
 })
+
+t.test('npx --no-install @npmcli/npx-test', async t => {
+  const registry = new MockRegistry({
+    tap: t,
+    registry: 'https://registry.npmjs.org/',
+  })
+
+  const manifest = registry.manifest({ name: '@npmcli/npx-test' })
+  manifest.versions['1.0.0'].bin = { 'npx-test': 'index.js' }
+
+  const { npm } = await loadMockNpm(t, {
+    config: {
+      audit: false,
+      yes: false,
+    },
+    prefixDir: {
+      'npm-exec-test': {
+        'package.json': JSON.stringify(manifest),
+        'index.js': `#!/usr/bin/env node
+  require('fs').writeFileSync('npm-exec-test-success', '')`,
+      },
+    },
+  })
+
+  try {
+    await npm.exec('exec', ['@npmcli/npx-test'])
+    t.fail('Expected error was not thrown')
+  } catch (error) {
+    t.match(
+      error.message,
+      'npx canceled due to missing packages and no YES option: ',
+      'Expected error message thrown'
+    )
+  }
+})

workspaces/libnpmexec/lib/index.js

@@ -245,9 +245,12 @@ const exec = async (opts) => {
 
     if (add.length) {
       if (!yes) {
+        const missingPackages = add.map(a => `${a.replace(/@$/, '')}`)
         // set -n to always say no
         if (yes === false) {
-          throw new Error('canceled')
+          // Error message lists missing package(s) when process is canceled
+          /* eslint-disable-next-line max-len */
+          throw new Error(`npx canceled due to missing packages and no YES option: ${JSON.stringify(missingPackages)}`)
         }
 
         if (noTTY() || ciInfo.isCI) {
@@ -257,8 +260,7 @@ const exec = async (opts) => {
             add.map((pkg) => pkg.replace(/@$/, '')).join(', ')
           }`)
         } else {
-          const addList = add.map(a => `  ${a.replace(/@$/, '')}`)
-            .join('\n') + '\n'
+          const addList = missingPackages.join('\n') + '\n'
           const prompt = `Need to install the following packages:\n${
           addList
         }Ok to proceed? `