make _replaySnapshot sync

Author: Uzlopak

lib/mock/snapshot-agent.js

@@ -182,39 +182,33 @@ class SnapshotAgent extends MockAgent {
    * Replays a recorded response
    */
   _replaySnapshot (snapshot, handler) {
-    return new Promise((resolve) => {
-      // Simulate the response
-      setImmediate(() => {
-        try {
-          const { response } = snapshot
-
-          const controller = {
-            pause () {},
-            resume () {},
-            abort (reason) {
-              this.aborted = true
-              this.reason = reason
-            },
-
-            aborted: false,
-            paused: false
-          }
-
-          handler.onRequestStart(controller)
-
-          handler.onResponseStart(controller, response.statusCode, response.headers)
-
-          // Body is always stored as base64 string
-          const body = Buffer.from(response.body, 'base64')
-          handler.onResponseData(controller, body)
-
-          handler.onResponseEnd(controller, response.trailers)
-          resolve()
-        } catch (error) {
-          handler.onError?.(error)
-        }
-      })
-    })
+    try {
+      const { response } = snapshot
+
+      const controller = {
+        pause () { },
+        resume () { },
+        abort (reason) {
+          this.aborted = true
+          this.reason = reason
+        },
+
+        aborted: false,
+        paused: false
+      }
+
+      handler.onRequestStart(controller)
+
+      handler.onResponseStart(controller, response.statusCode, response.headers)
+
+      // Body is always stored as base64 string
+      const body = Buffer.from(response.body, 'base64')
+      handler.onResponseData(controller, body)
+
+      handler.onResponseEnd(controller, response.trailers)
+    } catch (error) {
+      handler.onError?.(error)
+    }
   }
 
   /**