Validate config (#74)

* Validate config

* Refactor function

* Handle invalid values in arrays

* kebab-case that file

lib/build-app.js

@@ -9,8 +9,11 @@ import statusRoutes from "./routes.js";
 import { initHandleSigterm } from "./handle-sigterm.js";
 import notFoundHandler from "./notFoundHandler.js";
 import errorHandler from "./errorHandler.js";
+import validateConfig from "./config-validator.js";
 
 export default function buildApp(routes) {
+  validateConfig(config);
+
   const app = express();
 
   app.disable("x-powered-by");

lib/config-validator.js

@@ -0,0 +1,31 @@
+export default function validateConfig(config) {
+  const containsInvalidValues = JSON.stringify(config).includes("REPLACED_BY_ENV");
+
+  if (containsInvalidValues) {
+    const flattenedConfig = flattenObject(config);
+    const invalidValues = Object.keys(flattenedConfig).filter((key) => {
+      return flattenedConfig[key] === "REPLACED_BY_ENV";
+    });
+
+    if (invalidValues.length !== 0) {
+      throw new Error(`Invalid config for keys: ${invalidValues.join(", ")}`);
+    }
+
+    throw new Error("Config contains invalid values");
+  }
+}
+
+function flattenObject(o) {
+  const result = {};
+  for (const i in o) {
+    if ((typeof o[i]) === "object" && !Array.isArray(o[i])) {
+      const fo = flattenObject(o[i]);
+      for (const j in fo) {
+        result[`${i}.${j}`] = fo[j];
+      }
+    } else {
+      result[i] = o[i];
+    }
+  }
+  return result;
+}

test/lib/config-handler-test.js

@@ -0,0 +1,48 @@
+import { expect } from "chai";
+
+import validateConfig from "../../lib/config-validator.js";
+
+describe("Config validator", () => {
+  it("should not return anything", () => {
+    const config = {
+      envName: "test",
+      logClientIp: true,
+      express: { body: { limit: "200kb" } },
+    };
+    should.not.exist(validateConfig(config));
+  });
+
+  it("should throw error", () => {
+    const config = {
+      envName: "test",
+      logClientIp: true,
+      express: { body: { limit: "REPLACED_BY_ENV" } },
+    };
+    expect(() => validateConfig(config)).to.throw("Invalid config for keys: express.body.limit");
+  });
+
+  it("should throw error", () => {
+    const config = {
+      envName: "test",
+      logClientIp: true,
+      express: { body: { limit: "200kb" } },
+      items: [
+        { name: "REPLACED_BY_ENV" },
+        {
+          name: "yello",
+          value: "REPLACED_BY_ENV",
+        },
+      ],
+    };
+    expect(() => validateConfig(config)).to.throw("Config contains invalid values");
+  });
+
+  it("should throw error", () => {
+    const config = {
+      envName: "test",
+      logClientIp: "REPLACED_BY_ENV",
+      express: { body: { limit: "REPLACED_BY_ENV" } },
+    };
+    expect(() => validateConfig(config)).to.throw("Invalid config for keys: logClientIp, express.body.limit");
+  });
+});