Load test environment variables in Jest

nextConfig/extendEnv.ts

@@ -0,0 +1,68 @@
+const { extendNextConfig } = require("../packages/@vulcanjs/next-config");
+const flowRight = require("lodash/flowRight");
+const debug = require("debug")("vns:next");
+const packageJSON = require("../package.json");
+
+// fooBar => FOO_BAR
+const camelToTitle = (camelStr: string): string => {
+    return camelStr
+        .replace(/[A-Z]/g, " $1") // fooBar => foo Bar
+        .split(" ")
+        .map((t) => t.toUpperCase())
+        .join("_");
+};
+
+const withPkgInfo = (nextConfig) => {
+    // Public
+    // It's still unclear where such config should go
+    // @see https://github.com/vercel/next.js/discussions/14308
+    const publicPkgInfo = {
+        version: packageJSON.version,
+    };
+    if (!nextConfig.publicRuntimeConfig) nextConfig.publicRuntimeConfig = {};
+    nextConfig.publicRuntimeConfig.pkgInfo = publicPkgInfo;
+    // Also enhance environment with the same infos
+    Object.entries(publicPkgInfo).map(([key, value]) => {
+        const envKey = `NEXT_PUBLIC_PKGINFO_${camelToTitle(key)}`;
+        nextConfig.env[envKey] = `${value}`; // we convert to string
+    });
+
+    return nextConfig;
+};
+
+
+// @see https://nextjs.org/docs/api-reference/next.config.js/runtime-configuration
+module.exports = ({ defaultConfig }) => {
+    let extendedConfig;
+    extendedConfig = extendNextConfig(defaultConfig);
+
+    extendedConfig.env = {
+        NEXT_PUBLIC_IS_USING_DEMO_DATABASE: !!(process.env.MONGO_URI || "").match(
+            /lbke\-demo/
+        ),
+        NEXT_PUBLIC_IS_USING_LOCAL_DATABSE: !!(process.env.MONGO_URI || "").match(
+            /localhost/
+        ),
+    };
+
+    // Enable Webpack analyzer
+    if (process.env.ANALYZE && process.env.ANALYZE !== "false") {
+        const debug = require("debug")("webpack");
+        debug("Enabling Webpack bundle analyzer");
+        const withBundleAnalyzer = require("@next/bundle-analyzer")({
+            enabled: process.env.ANALYZE === "true",
+        });
+        extendedConfig = withBundleAnalyzer(extendedConfig);
+    }
+
+    // To support markdown import
+    extendedConfig.pageExtensions = ["js", "jsx", "md", "mdx", "ts", "tsx"];
+    extendedConfig = flowRight([
+        withPkgInfo,
+        // add other wrappers here
+    ])(extendedConfig);
+
+    debug("Extended next config FINAL " + JSON.stringify(extendedConfig));
+
+    return extendedConfig;
+};

tests/configTests/extendEnv.test.js

@@ -0,0 +1,8 @@
+describe('Can access to env variables', () => {
+    test('access to .env.test', () => {
+        expect(process.env.NEXT_PUBLIC_GRAPHQL_URI).toBeDefined()
+    })
+    test('access to derived variables', () => {
+        expect(process.env.NEXT_PUBLIC_IS_USING_LOCAL_DATABSE).toBeDefined()
+    })
+})

tests/globalSetup.js

@@ -1,14 +1,16 @@
 const { loadEnvConfig } = require("@next/env");
+const extendEnv = require('../nextConfig/extendEnv');
+
 module.exports = async () => {
+  console.info('Jest setupTests script will:');
   console.log("Loading environment variables in Jest from .env files");
   // @see https://github.com/vercel/next.js/issues/17903#issuecomment-708902413
   await loadEnvConfig(process.env.PWD);
   // Compute next.config env => it defines the constructed variables, so we need
   // to run it in Jest for the config to work correctly
-  /*
-  const envVariables = extendEnv({}).env; // TODO: we need to refactor next.config.js slightly to extract this "extendEnv" code
+  console.log("Loading derived variables in Jest");
+  const envVariables = extendEnv({}).env;
   Object.entries(envVariables).forEach(([varName, varValue]) => {
     process.env[varName] = varValue;
   });
-  */
 };