refactor: a save type is always present

src/api/install.ts

@@ -158,14 +158,12 @@ async function installInContext (
 
   let newPkg: Package | undefined = ctx.pkg
   if (installType === 'named') {
-    const saveType = getSaveType(opts)
-    if (saveType) {
-      if (!ctx.pkg) {
-        throw new Error('Cannot save because no package.json found')
-      }
-      const pkgJsonPath = path.join(ctx.root, 'package.json')
-      newPkg = await save(pkgJsonPath, pkgs.map(pkg => pkg.pkg), saveType, opts.saveExact)
+    if (!ctx.pkg) {
+      throw new Error('Cannot save because no package.json found')
     }
+    const pkgJsonPath = path.join(ctx.root, 'package.json')
+    const saveType = getSaveType(opts)
+    newPkg = await save(pkgJsonPath, pkgs.map(pkg => pkg.pkg), saveType, opts.saveExact)
   }
 
   if (newPkg) {

src/getSaveType.ts

@@ -1,9 +1,8 @@
 import {PnpmOptions} from './types'
 export type DependenciesType = 'dependencies' | 'devDependencies' | 'optionalDependencies'
 
-export default function getSaveType (opts: PnpmOptions): DependenciesType | null {
-  if (opts.save || opts.global) return 'dependencies'
+export default function getSaveType (opts: PnpmOptions): DependenciesType {
   if (opts.saveDev) return 'devDependencies'
   if (opts.saveOptional) return 'optionalDependencies'
-  return null
+  return 'dependencies'
 }