From 3de193f999a0750fac951e09682e860c68d88c5a Mon Sep 17 00:00:00 2001
From: =?utf8?q?J=C3=A9r=C3=B4me=20Benoit?= <jerome.benoit@sap.com>
Date: Sun, 15 Mar 2026 23:37:22 +0100
Subject: [PATCH] fix(ocpp): use per-subclass singleton map to prevent version
 collision
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The singleton instance was stored as a single static field on the base
class. In mixed OCPP 1.6/2.0 workers, the first getInstance() call
wins — subsequent calls for a different version silently return the
wrong instance cast via 'as T'.

Replace with Map<Constructor, Instance> keyed by the concrete subclass
constructor. Each version now gets its own singleton entry. Zero
changes needed in subclasses or calling code.
---
 .../ocpp/OCPPIncomingRequestService.ts               | 12 +++++++++---
 src/charging-station/ocpp/OCPPRequestService.ts      | 12 +++++++++---
 src/charging-station/ocpp/OCPPResponseService.ts     |  8 +++++---
 3 files changed, 23 insertions(+), 9 deletions(-)

diff --git a/src/charging-station/ocpp/OCPPIncomingRequestService.ts b/src/charging-station/ocpp/OCPPIncomingRequestService.ts
index 351aef63..c73a03ce 100644
--- a/src/charging-station/ocpp/OCPPIncomingRequestService.ts
+++ b/src/charging-station/ocpp/OCPPIncomingRequestService.ts
@@ -17,7 +17,11 @@ const ajvFormats = _ajvFormats.default
 const moduleName = 'OCPPIncomingRequestService'
 
 export abstract class OCPPIncomingRequestService extends EventEmitter {
-  private static instance: null | OCPPIncomingRequestService = null
+  private static readonly instances = new Map<
+    new () => OCPPIncomingRequestService,
+    OCPPIncomingRequestService
+  >()
+
   protected readonly ajv: Ajv
   protected abstract payloadValidatorFunctions: Map<
     IncomingRequestCommand,
@@ -39,8 +43,10 @@ export abstract class OCPPIncomingRequestService extends EventEmitter {
   }
 
   public static getInstance<T extends OCPPIncomingRequestService>(this: new () => T): T {
-    OCPPIncomingRequestService.instance ??= new this()
-    return OCPPIncomingRequestService.instance as T
+    if (!OCPPIncomingRequestService.instances.has(this)) {
+      OCPPIncomingRequestService.instances.set(this, new this())
+    }
+    return OCPPIncomingRequestService.instances.get(this) as T
   }
 
   // eslint-disable-next-line @typescript-eslint/no-unused-vars, @typescript-eslint/no-unnecessary-type-parameters
diff --git a/src/charging-station/ocpp/OCPPRequestService.ts b/src/charging-station/ocpp/OCPPRequestService.ts
index ce31ba90..19942fab 100644
--- a/src/charging-station/ocpp/OCPPRequestService.ts
+++ b/src/charging-station/ocpp/OCPPRequestService.ts
@@ -49,7 +49,11 @@ const defaultRequestParams: RequestParams = {
 }
 
 export abstract class OCPPRequestService {
-  private static instance: null | OCPPRequestService = null
+  private static readonly instances = new Map<
+    new (ocppResponseService: OCPPResponseService) => OCPPRequestService,
+    OCPPRequestService
+  >()
+
   protected readonly ajv: Ajv
   protected abstract payloadValidatorFunctions: Map<RequestCommand, ValidateFunction<JsonType>>
   private readonly ocppResponseService: OCPPResponseService
@@ -78,8 +82,10 @@ export abstract class OCPPRequestService {
     this: new (ocppResponseService: OCPPResponseService) => T,
     ocppResponseService: OCPPResponseService
   ): T {
-    OCPPRequestService.instance ??= new this(ocppResponseService)
-    return OCPPRequestService.instance as T
+    if (!OCPPRequestService.instances.has(this)) {
+      OCPPRequestService.instances.set(this, new this(ocppResponseService))
+    }
+    return OCPPRequestService.instances.get(this) as T
   }
 
   // eslint-disable-next-line @typescript-eslint/no-unnecessary-type-parameters
diff --git a/src/charging-station/ocpp/OCPPResponseService.ts b/src/charging-station/ocpp/OCPPResponseService.ts
index d6f122e1..baab610f 100644
--- a/src/charging-station/ocpp/OCPPResponseService.ts
+++ b/src/charging-station/ocpp/OCPPResponseService.ts
@@ -21,7 +21,7 @@ const ajvFormats = _ajvFormats.default
 const moduleName = 'OCPPResponseService'
 
 export abstract class OCPPResponseService {
-  private static instance: null | OCPPResponseService = null
+  private static readonly instances = new Map<new () => OCPPResponseService, OCPPResponseService>()
   public abstract incomingRequestResponsePayloadValidateFunctions: Map<
     IncomingRequestCommand,
     ValidateFunction<JsonType>
@@ -50,8 +50,10 @@ export abstract class OCPPResponseService {
   }
 
   public static getInstance<T extends OCPPResponseService>(this: new () => T): T {
-    OCPPResponseService.instance ??= new this()
-    return OCPPResponseService.instance as T
+    if (!OCPPResponseService.instances.has(this)) {
+      OCPPResponseService.instances.set(this, new this())
+    }
+    return OCPPResponseService.instances.get(this) as T
   }
 
   // eslint-disable-next-line @typescript-eslint/no-unnecessary-type-parameters
-- 
2.53.0