feat: verify package structure

src/main/ts/flows.ts

@@ -8,6 +8,7 @@ import {
   patchLockfile,
   printRuntimeDigest,
   syncLockfile,
+  verify,
   yarnImport,
   yarnInstall,
   yarnLockToPkgLock,
@@ -17,6 +18,7 @@ import {
 export const convert: TFlow = {
   main: [
     ['Runtime digest', printRuntimeDigest],
+    ['Verifying package structure...', verify],
     ['Preparing temp assets...', clear, createTempAssets, createSymlinks],
     ['Generating package-lock.json from yarn.lock...', yarnLockToPkgLock],
     ['Applying npm audit fix...', npmAuditFix],
@@ -36,6 +38,7 @@ export const convert: TFlow = {
 export const patch: TFlow = {
   main: [
     ['Runtime digest', printRuntimeDigest],
+    ['Verifying package structure...', verify],
     ['Preparing temp assets...', clear, createTempAssets, createSymlinks],
     [
       'Patching yarn.lock with audit data...',

src/main/ts/stages.ts

@@ -220,3 +220,18 @@ export const patchLockfile: TCallback = ({ temp, ctx }) => {
   lf.patch(lockfile, report, ctx)
   lf.write(lockfilePath, lockfile)
 }
+
+/**
+ * Check that everything is fine with pkg dir.
+ * @param {TContext} cxt
+ * @return {void}
+ */
+export const verify: TCallback = ({ cwd }) => {
+  const required = ['yarn.lock', 'package.json', 'node_modules']
+
+  required.forEach(resource => {
+    if (!fs.existsSync(join(cwd, resource))) {
+      throw new Error(`not found: ${resource}`)
+    }
+  })
+}

src/test/ts/runner.ts

@@ -213,10 +213,20 @@ describe('yarn-audit-fix', () => {
       expect(handler).toHaveBeenCalledTimes(1)
     })
 
+    it('throws error on broken package structure', async () => {
+      // @ts-ignore
+      fs.existsSync.mockReturnValueOnce(false)
+
+      expect(run({cwd: 'unknown'})).rejects.toEqual(
+        new Error('not found: yarn.lock')
+      )
+    })
+
     it('throws error on unsupported flow', async () =>
       expect(run({ flow: 'unknown' })).rejects.toEqual(
         new Error('Unsupported flow: unknown'),
-      ))
+      )
+    )
 
     describe('`patch` flow', () => {
       it('invokes cmd queue with proper args', async () => {