feat: recursively merge the network config override

Author: schaable

v-next/hardhat/src/internal/builtin-plugins/network-manager/config-override.ts

@@ -0,0 +1,94 @@
+import type {
+  EdrNetworkUserConfig,
+  HttpNetworkUserConfig,
+  NetworkConfig,
+  NetworkConfigOverride,
+  NetworkUserConfig,
+} from "../../../types/config.js";
+
+import { isObject } from "@ignored/hardhat-vnext-utils/lang";
+
+/**
+ * Converts the NetworkConfigOverride into a valid NetworkUserConfig. This
+ * function determines the network type based on the provided `networkConfig`
+ * and sets default values for any required properties that are missing from
+ * the `networkConfigOverride`.
+ *
+ * @warning
+ * This function is not type-safe. It assumes that `networkConfigOverride` does
+ * not contain mixed properties from different network types. Always validate
+ * the resulting NetworkUserConfig before using it.
+ *
+ * @param networkConfigOverride The partial configuration override provided by
+ * the user.
+ * @param networkConfig The base network configuration used to infer defaults
+ * and the network type.
+ * @returns A fully resolved NetworkUserConfig with defaults applied.
+ */
+export async function normalizeNetworkConfigOverride(
+  networkConfigOverride: NetworkConfigOverride,
+  networkConfig: NetworkConfig,
+): Promise<NetworkUserConfig> {
+  let networkConfigOverrideWithType: NetworkUserConfig;
+
+  if (networkConfig.type === "http") {
+    const networkConfigOverrideAsHttp =
+      /* eslint-disable-next-line @typescript-eslint/consistent-type-assertions
+      -- Assumes that networkConfigOverride is a HttpNetworkUserConfig. */
+      networkConfigOverride as HttpNetworkUserConfig;
+
+    networkConfigOverrideWithType = {
+      ...networkConfigOverrideAsHttp,
+      type: "http",
+      url: networkConfigOverrideAsHttp.url ?? (await networkConfig.url.get()),
+    };
+  } else {
+    const networkConfigOverrideAsEdr =
+      /* eslint-disable-next-line @typescript-eslint/consistent-type-assertions
+      -- Assumes that networkConfigOverride is an EdrNetworkUserConfig. */
+      networkConfigOverride as EdrNetworkUserConfig;
+
+    networkConfigOverrideWithType = {
+      ...networkConfigOverrideAsEdr,
+      type: "edr",
+    };
+  }
+
+  return networkConfigOverrideWithType;
+}
+
+/**
+ * Merges two network configurations. This function is used to merge the
+ * network configuration with the network configuration override. It recursively
+ * merges nested objects.
+ *
+ * @param target The resolved network configuration.
+ * @param source The partial network configuration override provided by the user. It
+ * should be resolved and contain only the properties that the user wants to
+ * override.
+ * @returns A new network configuration object with the override applied.
+ */
+export function mergeConfigOverride<T extends object>(
+  target: T,
+  source: Partial<T> = {},
+): T {
+  const result = { ...target };
+
+  for (const key in source) {
+    if (isObject(source[key])) {
+      /* eslint-disable-next-line @typescript-eslint/consistent-type-assertions
+      -- result[key] is either an object or undefined, so we default it to {} */
+      result[key] = mergeConfigOverride(
+        result[key] ?? {},
+        source[key],
+      ) as T[Extract<keyof T, string>];
+    } else {
+      /* eslint-disable-next-line @typescript-eslint/consistent-type-assertions
+      -- source[key] could be undefined, but as it is a resolved config as well,
+      result[key] should allow it */
+      result[key] = source[key] as T[Extract<keyof T, string>];
+    }
+  }
+
+  return result;
+}

v-next/hardhat/src/internal/builtin-plugins/network-manager/network-manager.ts

@@ -1,9 +1,6 @@
 import type {
-  EdrNetworkUserConfig,
-  HttpNetworkUserConfig,
   NetworkConfig,
   NetworkConfigOverride,
-  NetworkUserConfig,
 } from "../../../types/config.js";
 import type { HookManager } from "../../../types/hooks.js";
 import type {
@@ -22,6 +19,10 @@ import { HardhatError } from "@ignored/hardhat-vnext-errors";
 
 import { resolveConfigurationVariable } from "../../core/configuration-variables.js";
 
+import {
+  mergeConfigOverride,
+  normalizeNetworkConfigOverride,
+} from "./config-override.js";
 import { resolveNetworkConfigOverride } from "./config-resolution.js";
 import { EdrProvider } from "./edr/edr-provider.js";
 import { isEdrSupportedChainType } from "./edr/utils/chain-type.js";
@@ -138,12 +139,10 @@ export class NetworkManagerImplementation implements NetworkManager {
       );
     }
 
-    /* eslint-disable-next-line @typescript-eslint/consistent-type-assertions
-    -- Cast to NetworkConfig as we know the types match, but TS can't infer it */
-    const resolvedNetworkConfig = {
-      ...this.#networkConfigs[resolvedNetworkName],
-      ...resolvedNetworkConfigOverride,
-    } as NetworkConfig;
+    const resolvedNetworkConfig = mergeConfigOverride(
+      this.#networkConfigs[resolvedNetworkName],
+      resolvedNetworkConfigOverride,
+    );
 
     /* eslint-disable-next-line @typescript-eslint/consistent-type-assertions
     -- Cast to ChainTypeT because we know it's valid */
@@ -236,52 +235,3 @@ export class NetworkManagerImplementation implements NetworkManager {
     );
   }
 }
-
-/**
- * Converts the NetworkConfigOverride into a valid NetworkUserConfig. This
- * function determines the network type based on the provided `networkConfig`
- * and sets default values for any required properties that are missing from
- * the `networkConfigOverride`.
- *
- * @warning
- * This function is not type-safe. It assumes that `networkConfigOverride` does
- * not contain mixed properties from different network types. Always validate
- * the resulting NetworkUserConfig before using it.
- *
- * @param networkConfigOverride The partial configuration override provided by
- * the user.
- * @param networkConfig The base network configuration used to infer defaults
- * and the network type.
- * @returns A fully resolved NetworkUserConfig with defaults applied.
- */
-async function normalizeNetworkConfigOverride(
-  networkConfigOverride: NetworkConfigOverride,
-  networkConfig: NetworkConfig,
-): Promise<NetworkUserConfig> {
-  let networkConfigOverrideWithType: NetworkUserConfig;
-
-  if (networkConfig.type === "http") {
-    const networkConfigOverrideAsHttp =
-      /* eslint-disable-next-line @typescript-eslint/consistent-type-assertions
-      -- Assumes that networkConfigOverride is a HttpNetworkUserConfig. */
-      networkConfigOverride as HttpNetworkUserConfig;
-
-    networkConfigOverrideWithType = {
-      ...networkConfigOverrideAsHttp,
-      type: "http",
-      url: networkConfigOverrideAsHttp.url ?? (await networkConfig.url.get()),
-    };
-  } else {
-    const networkConfigOverrideAsEdr =
-      /* eslint-disable-next-line @typescript-eslint/consistent-type-assertions
-      -- Assumes that networkConfigOverride is an EdrNetworkUserConfig. */
-      networkConfigOverride as EdrNetworkUserConfig;
-
-    networkConfigOverrideWithType = {
-      ...networkConfigOverrideAsEdr,
-      type: "edr",
-    };
-  }
-
-  return networkConfigOverrideWithType;
-}