fix: should work when only current shrinkwrap.yaml is available

src/index.ts

@@ -94,6 +94,7 @@ async function _outdated (
   },
 ): Promise<OutdatedPackage[]> {
   const wantedShrinkwrap = await readWantedShrinkwrap(pkgPath, {ignoreIncompatible: false})
+    || await readCurrentShrinkwrap(pkgPath, {ignoreIncompatible: false})
   if (!wantedShrinkwrap) {
     throw new Error('No shrinkwrapfile in this directory. Run `pnpm install` to generate one.')
   }

test/fixtures/current-shrinkwrap-only/.gitignore

@@ -0,0 +1 @@
+!node_modules

test/fixtures/current-shrinkwrap-only/node_modules/.shrinkwrap.yaml

@@ -0,0 +1,27 @@
+dependencies:
+  is-negative: 1.1.0
+  is-positive: 3.1.0
+  from-github: github.com/blabla/from-github/d5f8d5500f7faf593d32e134c1b0043ff69151b3
+  from-github-2: github.com/blabla/from-github-2/d5f8d5500f7faf593d32e134c1b0043ff69151b3
+packages:
+  /is-negative/1.1.0:
+    resolution:
+      integrity: sha1-8Nhjd6oVpkw0lh84rCqb4rQKEYc=
+  /is-positive/3.1.0:
+    resolution:
+      integrity: sha1-hX21hKG6XRyymAUn/DtsQ103sP0=
+  github.com/blabla/from-github/d5f8d5500f7faf593d32e134c1b0043ff69151b3:
+    name: from-github
+    version: 1.0.0
+    resolution:
+      tarball: 'https://codeload.github.com/blabla/from-github/tar.gz/d5f8d5500f7faf593d32e134c1b0043ff69151b3'
+  github.com/blabla/from-github-2/d5f8d5500f7faf593d32e134c1b0043ff69151b3:
+    name: from-github-2
+    version: 1.0.0
+    resolution:
+      tarball: 'https://codeload.github.com/blabla/from-github-2/tar.gz/d5f8d5500f7faf593d32e134c1b0043ff69151b3'
+registry: 'https://registry.npmjs.org/'
+shrinkwrapVersion: 3
+specifiers:
+  is-negative: ^2.1.0
+  is-positive: ^3.1.0

test/fixtures/current-shrinkwrap-only/package.json

@@ -0,0 +1,8 @@
+{
+  "name": "wanted-shrinkwrap",
+  "version": "1.0.0",
+  "dependencies": {
+    "is-negative": "^2.1.0",
+    "is-positive": "^3.1.0"
+  }
+}

test/index.ts

@@ -75,3 +75,16 @@ test('forPackages()', async (t) => {
   ])
   t.end()
 })
+
+test('outdated() when only current shrinkwrap is present', async (t) => {
+  const outdatedPkgs = await outdated('current-shrinkwrap-only', outdatedOpts)
+  t.deepEqual(outdatedPkgs, [
+    {
+      current: '1.1.0',
+      latest: '2.1.0',
+      packageName: 'is-negative',
+      wanted: '1.1.0',
+    },
+  ])
+  t.end()
+})