hardhat-deploy-config: add getter

Add a getter to the `hre.deployConfig` object
that gives access to alternative network's deploy
configs. This is useful because multiple networks
can be linked and share config. In particular when
L2 networks are used with L1 networks, the entire
deploy config has be be shared with both networks
so it results in a copy paste.

.changeset/poor-carrots-walk.md

+---
+'@eth-optimism/hardhat-deploy-config': patch
+---
+
+Add getter for other network's deploy config

packages/hardhat-deploy-config/src/plugin.ts

@@ -27,9 +27,10 @@ const normalizePath = (
 }
 
 export const loadDeployConfig = (hre: HardhatRuntimeEnvironment): any => {
+  const getDeployConfig = (dir: string, network: string): any => {
     let config: any
     try {
-    const base = `${hre.config.paths.deployConfig}/${hre.network.name}`
+      const base = `${dir}/${network}`
       if (fs.existsSync(`${base}.ts`)) {
         // eslint-disable-next-line @typescript-eslint/no-var-requires
         config = require(`${base}.ts`).default
@@ -44,15 +45,24 @@ export const loadDeployConfig = (hre: HardhatRuntimeEnvironment): any => {
         `error while loading deploy config for network: ${hre.network.name}, ${err}`
       )
     }
+    return config
+  }
+
+  const paths = hre.config.paths.deployConfig
+  const conf = getDeployConfig(paths, hre.network.name)
+  const spec = parseDeployConfig(hre, conf)
+
+  spec.getDeployConfig = (network: string) => {
+    return getDeployConfig(paths, network)
+  }
 
-  return new Proxy(parseDeployConfig(hre, config), {
+  return new Proxy(spec, {
     get: (target, prop) => {
       if (target.hasOwnProperty(prop)) {
         return target[prop]
       }
 
-      // Explicitly throw if the property is not found since I can't yet figure out a good way to
-      // handle the necessary typings.
+      // Explicitly throw if the property is not found
       throw new Error(
         `property does not exist in deploy config: ${String(prop)}`
       )

packages/hardhat-deploy-config/src/type-extensions.ts

@@ -24,8 +24,8 @@ declare module 'hardhat/types/config' {
 declare module 'hardhat/types/runtime' {
   interface HardhatRuntimeEnvironment {
     deployConfig: {
-      // TODO: Is there any good way to type this?
       [key: string]: any
+      getDeployConfig(arg0: string): { [key: string]: any }
     }
   }
 }