Clean up package manager resolution.

src/cli-options.ts

@@ -517,7 +517,6 @@ const cliOptions: CLIOption[] = [
     long: 'packageManager',
     short: 'p',
     arg: 's',
-    // manual default to allow overriding auto yarn detection
     description: 'npm, yarn, pnpm, staticRegistry (default: npm).',
     help: extendedHelpPackageManager,
     type: `'npm' | 'yarn' | 'pnpm' | 'staticRegistry'`,

src/lib/determinePackageManager.ts

@@ -1,32 +1,30 @@
 import fs from 'fs/promises'
+import { Index } from '../types/IndexType'
 import { Options } from '../types/Options'
 import { PackageManagerName } from '../types/PackageManagerName'
 import findLockfile from './findLockfile'
 
-const defaultPackageManager = 'npm'
+// map lockfiles to package managers
+const packageManagerLockfileMap: Index<PackageManagerName> = {
+  'package-lock': 'npm',
+  yarn: 'yarn',
+  'pnpm-lock': 'pnpm',
+}
 
 /**
  * If the packageManager option was not provided, look at the lockfiles to
  * determine which package manager is being used.
- *
- * @param readdirSync This is only a parameter so that it can be used in tests.
  */
 const determinePackageManager = async (
   options: Options,
+  // only for testing
   readdir: (_path: string) => Promise<string[]> = fs.readdir,
 ): Promise<PackageManagerName> => {
   if (options.packageManager) return options.packageManager
-  else if (options.global) return defaultPackageManager
+  else if (options.global) return 'npm'
 
   const lockfileName = (await findLockfile(options, readdir))?.filename
-
-  return lockfileName === 'package-lock.json'
-    ? 'npm'
-    : lockfileName === 'yarn.lock'
-    ? 'yarn'
-    : lockfileName === 'pnpm-lock.yaml'
-    ? 'pnpm'
-    : defaultPackageManager
+  return lockfileName ? packageManagerLockfileMap[lockfileName.split('.')[0]] : 'npm'
 }
 
 export default determinePackageManager

src/lib/findLockfile.ts

@@ -5,7 +5,7 @@ import { Options } from '../types/Options'
 /**
  * Goes up the filesystem tree until it finds a package-lock.json or yarn.lock.
  *
- * @param readdirSync This is only a parameter so that it can be used in tests.
+ * @param readdir This is only a parameter so that it can be used in tests.
  * @returns The path of the directory that contains the lockfile and the
  * filename of the lockfile.
  */

src/lib/getPackageManager.ts

@@ -12,7 +12,7 @@ import { PackageManager } from '../types/PackageManager'
  */
 function getPackageManager(name: Maybe<string>): PackageManager {
   // default to npm
-  if (!name || name === 'deno') {
+  if (!name) {
     return packageManagers.npm
   }
 

src/lib/initOptions.ts

@@ -154,19 +154,17 @@ async function initOptions(runOptions: RunOptions, { cli }: { cli?: boolean } =
 
   const autoPre = target === 'newest' || target === 'greatest'
 
-  const format = options.format || []
-
   const packageManager = await determinePackageManager(options)
 
-  // only print 'Using yarn' when autodetected
-  if (!options.packageManager && packageManager === 'yarn') {
-    print(options, 'Using yarn')
+  // print 'Using yarn/pnpm/etc' when autodetected
+  if (!options.packageManager && packageManager !== 'npm') {
+    print(options, `Using ${packageManager}`)
   }
 
-  const resolvedOptions = {
+  const resolvedOptions: Options = {
     ...options,
     ...(options.deep ? { packageFile: '**/package.json' } : null),
-    ...(format.length > 0 ? { format } : null),
+    ...(options.format && options.format.length > 0 ? { format: options.format } : null),
     filter: args || filter,
     // add shortcut for any keys that start with 'json'
     json,