feat: Add ChugSplash config parsing via Handlebars

packages/contracts/package.json

@@ -51,7 +51,8 @@
     "@openzeppelin/contracts-upgradeable": "^3.3.0",
     "@typechain/hardhat": "^1.0.1",
     "ganache-core": "^2.13.2",
-    "glob": "^7.1.6"
+    "glob": "^7.1.6",
+    "handlebars": "^4.7.7"
   },
   "devDependencies": {
     "@eth-optimism/hardhat-ovm": "^0.1.0",

packages/contracts/src/chugsplash/config.ts

@@ -0,0 +1,94 @@
+/* Imports: External */
+import * as Handlebars from 'handlebars'
+import { ethers } from 'ethers'
+
+type SolidityVariable =
+  | string
+  | number
+  | Array<SolidityVariable>
+  | {
+      [name: string]: SolidityVariable
+    }
+
+export interface ChugSplashConfig {
+  contracts: {
+    [name: string]: {
+      address: string
+      source: string
+      variables?: {
+        [name: string]: SolidityVariable
+      }
+    }
+  }
+}
+
+/**
+ * Parses a ChugSplash config file by replacing template values.
+ * @param config Unparsed config file to parse.
+ * @param env Environment variables to inject into the file.
+ * @return Parsed config file with template variables replaced.
+ */
+export const parseChugSplashConfig = (
+  config: ChugSplashConfig,
+  env: any = {}
+): ChugSplashConfig => {
+  config.contracts = config.contracts || {}
+
+  const contracts = {}
+  for (const [contractName, contractConfig] of Object.entries(
+    config.contracts
+  )) {
+    // Block people from accidentally using templates in contract names.
+    if (contractName.includes('{') || contractName.includes('}')) {
+      throw new Error(
+        `cannot use template strings in contract names: ${contractName}`
+      )
+    }
+
+    // Block people from accidentally using templates in contract names.
+    if (
+      contractConfig.source.includes('{') ||
+      contractConfig.source.includes('}')
+    ) {
+      throw new Error(
+        `cannot use template strings in contract source names: ${contractConfig.source}`
+      )
+    }
+
+    // Make sure addresses are fixed and are actually addresses.
+    if (!ethers.utils.isAddress(contractConfig.address)) {
+      throw new Error(
+        `contract address is not a valid address: ${contractConfig.address}`
+      )
+    }
+
+    contracts[contractName] = contractConfig.address
+  }
+
+  return JSON.parse(
+    Handlebars.compile(JSON.stringify(config))({
+      env: new Proxy(env, {
+        get: (target, prop) => {
+          const val = target[prop]
+          if (val === undefined) {
+            throw new Error(
+              `attempted to access unknown env value: ${prop as any}`
+            )
+          }
+          return val
+        },
+      }),
+      contracts: new Proxy(contracts, {
+        get: (target, prop) => {
+          const val = target[prop]
+          if (val === undefined) {
+            throw new Error(
+              `attempted to access unknown contract: ${prop as any}`
+            )
+          }
+          return val
+        },
+      }),
+    })
+  )
+}

packages/contracts/src/chugsplash/index.ts

@@ -0,0 +1 @@
+export * from './config'

packages/contracts/src/index.ts

@@ -2,3 +2,4 @@ export * from './contract-defs'
 export { getLatestStateDump, StateDump } from './contract-dumps'
 export * from './contract-deployment'
 export * from './predeploys'
+export * from './chugsplash'