Set Issue labels by inputs & add unit test (#12)

* Set Issue labels by inputs

* Add unit test

src/audit.ts

@@ -0,0 +1,30 @@
+import {spawnSync, SpawnSyncReturns} from 'child_process'
+
+export class Audit {
+  stdout: string = ''
+  status: number | null = null
+
+  public async run(): Promise<void> {
+    const result: SpawnSyncReturns<string> = spawnSync('npm', ['audit'], {
+      encoding: 'utf-8'
+    })
+
+    if (result.error) {
+      throw result.error
+    }
+    if (result.status === null) {
+      throw new Error('the subprocess terminated due to a signal.')
+    }
+    if (result.stderr && result.stderr.length > 0) {
+      throw new Error(result.stderr)
+    }
+
+    this.status = result.status
+    this.stdout = result.stdout
+  }
+
+  public foundVulnerability(): boolean {
+    // `npm audit` return 1 when it found vulnerabilities
+    return this.status === 1
+  }
+}