feat: add expiretime command

Author: stipsan

src/commands/expiretime.js

@@ -0,0 +1,13 @@
+export function expiretime(key) {
+  if (!this.data.has(key)) {
+    return -2
+  }
+
+  if (!this.expires.has(key)) {
+    return -1
+  }
+
+  return Math.round(this.expires.get(key) / 1000)
+}
+
+export const expiretimeBuffer = expiretime

src/commands/index.js

@@ -20,6 +20,7 @@ export * from './evalsha'
 export * from './exists'
 export * from './expire'
 export * from './expireat'
+export * from './expiretime'
 export * from './failover'
 export * from './flushall'
 export * from './flushdb'