From f37a52da28ac130b7f4de52901618320994ea87a Mon Sep 17 00:00:00 2001
From: Richard Moore <github@ricmoo.com>
Date: Tue, 6 Jun 2023 17:58:06 -0400
Subject: [PATCH] Added support to detect and stop providers spinning on
 intitial network detection (#4015).

---
 src.ts/providers/abstract-provider.ts | 19 +++++++++++-
 src.ts/providers/provider-jsonrpc.ts  | 43 ++++++++++++++++++++-------
 2 files changed, 51 insertions(+), 11 deletions(-)

diff --git a/src.ts/providers/abstract-provider.ts b/src.ts/providers/abstract-provider.ts
index 30587bd745..63e07ae6d8 100644
--- a/src.ts/providers/abstract-provider.ts
+++ b/src.ts/providers/abstract-provider.ts
@@ -421,6 +421,8 @@ export class AbstractProvider implements Provider {
     // null=unpaused, true=paused+dropWhilePaused, false=paused
     #pausedState: null | boolean;
 
+    #destroyed: boolean;
+
     #networkPromise: null | Promise<Network>;
     readonly #anyNetwork: boolean;
 
@@ -462,6 +464,8 @@ export class AbstractProvider implements Provider {
         this.#plugins = new Map();
         this.#pausedState = null;
 
+        this.#destroyed = false;
+
         this.#nextTimer = 1;
         this.#timers = new Map();
 
@@ -1445,9 +1449,20 @@ export class AbstractProvider implements Provider {
        return this.off(event, listener);
     }
 
+    /**
+     *  If this provider has been destroyed using the [[destroy]] method.
+     *
+     *  Once destroyed, all resources are reclaimed, internal event loops
+     *  and timers are cleaned up and no further requests may be sent to
+     *  the provider.
+     */
+    get destroyed(): boolean {
+        return this.#destroyed;
+    }
+
     /**
      *  Sub-classes may use this to shutdown any sockets or release their
-     *  resources.
+     *  resources and reject any pending requests.
      *
      *  Sub-classes **must** call ``super.destroy()``.
      */
@@ -1459,6 +1474,8 @@ export class AbstractProvider implements Provider {
         for (const timerId of this.#timers.keys()) {
             this._clearTimeout(timerId);
         }
+
+        this.#destroyed = true;
     }
 
     /**
diff --git a/src.ts/providers/provider-jsonrpc.ts b/src.ts/providers/provider-jsonrpc.ts
index bdcf7d9be7..cf9732a34a 100644
--- a/src.ts/providers/provider-jsonrpc.ts
+++ b/src.ts/providers/provider-jsonrpc.ts
@@ -495,6 +495,11 @@ export abstract class JsonRpcApiProvider extends AbstractProvider {
                         // Process results in batch order
                         for (const { resolve, reject, payload } of batch) {
 
+                            if (this.destroyed) {
+                                reject(makeError("provider destroyed; cancelled request", "UNSUPPORTED_OPERATION", { operation: payload.method }));
+                                continue;
+                            }
+
                             // Find the matching result
                             const resp = result.filter((r) => (r.id === payload.id))[0];
 
@@ -506,7 +511,6 @@ export abstract class JsonRpcApiProvider extends AbstractProvider {
                             // The response is an error
                             if ("error" in resp) {
                                 return reject(this.getRpcError(payload, resp));
-
                             }
 
                             // All good; send the result
@@ -578,13 +582,6 @@ export abstract class JsonRpcApiProvider extends AbstractProvider {
      *  Sub-classes **MUST** override this.
      */
     abstract _send(payload: JsonRpcPayload | Array<JsonRpcPayload>): Promise<Array<JsonRpcResult | JsonRpcError>>;
-    /*
-     {
-        assert(false, "sub-classes must override _send", "UNSUPPORTED_OPERATION", {
-            operation: "jsonRpcApiProvider._send"
-        });
-    }
-    */
 
 
     /**
@@ -678,11 +675,12 @@ export abstract class JsonRpcApiProvider extends AbstractProvider {
         (async () => {
 
             // Bootstrap the network
-            while (this.#network == null) {
+            while (this.#network == null && !this.destroyed) {
                 try {
                     this.#network = await this._detectNetwork();
                 } catch (error) {
-                    console.log("JsonRpcProvider failed to startup; retry in 1s");
+                    console.log("JsonRpcProvider failed to detect network and cannot start up; retry in 1s (perhaps the URL is wrong or the node is not started)");
+                    this.emit("error", makeError("failed to bootstrap network detection", "NETWORK_ERROR", { event: "initial-network-discovery", info: { error } }));
                     await stall(1000);
                 }
             }
@@ -973,6 +971,11 @@ export abstract class JsonRpcApiProvider extends AbstractProvider {
     send(method: string, params: Array<any> | Record<string, any>): Promise<any> {
         // @TODO: cache chainId?? purge on switch_networks
 
+        // We have been destroyed; no operations are supported anymore
+        if (this.destroyed) {
+            return Promise.reject(makeError("provider destroyed; cancelled request", "UNSUPPORTED_OPERATION", { operation: method }));
+        }
+
         const id = this.#nextId++;
         const promise = new Promise((resolve, reject) => {
             this.#payloads.push({
@@ -1031,6 +1034,26 @@ export abstract class JsonRpcApiProvider extends AbstractProvider {
         const accounts: Array<string> = await this.send("eth_accounts", [ ]);
         return accounts.map((a) => new JsonRpcSigner(this, a));
     }
+
+    destroy(): void {
+
+        // Stop processing requests
+        if (this.#drainTimer) {
+            clearTimeout(this.#drainTimer);
+            this.#drainTimer = null;
+        }
+
+        // Cancel all pending requests
+        for (const { payload, reject } of this.#payloads) {
+            reject(makeError("provider destroyed; cancelled request", "UNSUPPORTED_OPERATION", { operation: payload.method }));
+        }
+
+        this.#payloads = [ ];
+
+        // Parent clean-up
+        super.destroy();
+
+    }
 }
 
 export abstract class JsonRpcApiPollingProvider extends JsonRpcApiProvider {