feat(config): load config by detecting environment from NODE_ENV (#171)

* feat(config): load configuration based on NODE_ENV environment variable

* docs(config): add loadConfigFromNodeEnv() example

* refactor: move loadConfigFromNodeEnv() to Chains.loadFromNodeEnv()

* docs: update README examples

* refactor: import with a "package name" config

Author: kare

packages/config/README.md

@@ -13,13 +13,20 @@ npm install --save @streamr/config
 ## Examples
 Import DATA token production Ethereum address as a variable in a Typescript project:
 ```typescript
-import { Chains } from "index"
+import * as config from "config"
 
-const config: Chains = Chains.load("production")
-const contractAddress: string = config.ethereum.contracts["DATA-token"]
-const chainId: number = config.ethereum.id
-const rpcHttpUrl: string = config.ethereum.rpcHttpUrl
-const rpcWsUrl: string = config.ethereum.rpcWsUrl
+const chains: config.Chains = config.Chains.load("production")
+const contractAddress: string = chains.ethereum.contracts["DATA-token"]
+const chainId: number = chains.ethereum.id
+const httpRpcEndpoints: RPCEndpoint[] = chains.ethereum.getRPCEndpointsByProtocol(RPCProtocol.HTTP)
+const wsRpcEndpoints: RPCEndpoint[] = chains.ethereum.getRPCEndpointsByProtocol(RPCProtocol.WEBSOCKET)
+```
+
+You can also load configuration based on `$NODE_ENV` environment variable:
+```typescript
+import * as config from "config"
+
+const chains: Chains = config.Chains.loadFromNodeEnv()
 ```
 
 Other languages can read the [JSON file](./src/networks.json) directly.

packages/config/src/index.ts renamed to packages/config/src/config.ts

@@ -81,6 +81,17 @@ export class Chains implements ChainsJSON {
         const chains: Chains = ChainsFactory.create(chainsJson)
         return chains
     }
+    public static loadFromNodeEnv(): Chains {
+        const nodeEnv = process.env.NODE_ENV
+        if (nodeEnv === undefined) {
+            throw new Error("NODE_ENV environment variable is not set")
+        }
+        if (nodeEnv !== "production" && nodeEnv !== "development") {
+            throw new Error("NODE_ENV environment variable value must be either 'production' or 'development'")
+        }
+        const env: Environment = nodeEnv
+        return Chains.load(env)
+    }
 }
 
 class ChainsFactory {

packages/config/test/config.test.ts

@@ -0,0 +1,66 @@
+import { describe, it } from "mocha"
+import { assert } from "chai"
+import * as config from "../src/config"
+
+describe("Load configuration from JSON file", () => {
+    it("ethereum chain id is 1", () => {
+        const chains: config.Chains = config.Chains.load("production")
+        const chainId: number = chains.ethereum.id
+        const expected = 1
+        assert.equal(chainId, expected, `Expecting ethereum prod chain id to equal ${expected}, got '${chainId}'`)
+    })
+    it("development chain id is 8995", () => {
+        const chains: config.Chains = config.Chains.load("development")
+        const chainId: number = chains.ethereum.id
+        const expected = 8995
+        assert.equal(chainId, expected, `Expecting ethereum dev chain id to equal ${expected}, got '${chainId}'`)
+    })
+    it("reads DATA token dev address from JSON", () => {
+        const chains: config.Chains = config.Chains.load("development")
+        const address = chains.ethereum.contracts["DATA-token"]
+        const expected = "0xbAA81A0179015bE47Ad439566374F2Bae098686F"
+        assert.equal(address, expected, `Expecting ethereum DATA token to equal ${expected}, got '${address}'`)
+    })
+    it("reads prod Polygon RPC URL", () => {
+        const chains: config.Chains = config.Chains.load("production")
+        const rpcHttpUrl = chains.polygon.rpcEndpoints[0].url
+        const expected = "https://polygon-rpc.com"
+        assert.equal(rpcHttpUrl, expected, `Expecting prod polygon RPC URL to equal ${expected}, got '${rpcHttpUrl}'`)
+    })
+    it("finds RPC endpoints by protocol", () => {
+        const chains: config.Chains = config.Chains.load("production")
+        const endpoints = chains.binance.getRPCEndpointsByProtocol(config.RPCProtocol.HTTP)
+        assert.equal(endpoints.length, 1)
+        assert.equal(endpoints[0].url, "https://bsc-dataseed.binance.org")
+    })
+})
+describe("Load configuration based on NODE_ENV environment variable", () => {
+    it("ethereum chain id is 1", () => {
+        process.env.NODE_ENV = "production"
+        const chains: config.Chains = config.Chains.loadFromNodeEnv()
+        const chainId: number = chains.ethereum.id
+        const expected = 1
+        assert.equal(chainId, expected, `Expecting ethereum prod chain id to equal ${expected}, got '${chainId}'`)
+    })
+    it("development chain id is 8995", () => {
+        process.env.NODE_ENV = "development"
+        const chains: config.Chains = config.Chains.loadFromNodeEnv()
+        const chainId: number = chains.ethereum.id
+        const expected = 8995
+        assert.equal(chainId, expected, `Expecting ethereum dev chain id to equal ${expected}, got '${chainId}'`)
+    })
+    it("errors when NODE_ENV is not set", () => {
+        delete process.env.NODE_ENV
+        assert.throws(() => {
+            /* eslint-disable @typescript-eslint/no-unused-vars */
+            const chains: config.Chains = config.Chains.loadFromNodeEnv()
+        }, /NODE_ENV environment variable is not set/)
+    })
+    it("errors when NODE_ENV is something else than 'production' or 'development'", () => {
+        process.env.NODE_ENV = "dev"
+        assert.throws(() => {
+            /* eslint-disable @typescript-eslint/no-unused-vars */
+            const chains: config.Chains = config.Chains.loadFromNodeEnv()
+        }, /NODE_ENV environment variable value must be either 'production' or 'development'/)
+    })
+})