Typescriptify ConfigValidator

changelog.d/205.misc

@@ -0,0 +1 @@
+Typescriptify ConfigValidator

package.json

@@ -42,6 +42,7 @@
   },
   "devDependencies": {
     "@types/bluebird": "^3.5.32",
+    "@types/extend": "^3.0.1",
     "@types/js-yaml": "^3.12.5",
     "@types/node": "^10",
     "@types/nopt": "^3.0.29",

src/components/cli.ts

@@ -32,7 +32,7 @@ interface CliOpts<ConfigType extends Record<string, unknown>> {
     bridgeConfig?: {
         affectsRegistration?: boolean;
         schema: string|Record<string, unknown>;
-        defaults: string|Record<string, unknown>;
+        defaults: Record<string, unknown>;
     };
     registrationPath: string;
     enableRegistration?: boolean;

src/components/config-validator.ts

@@ -0,0 +1,75 @@
+/*
+Copyright 2020 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+import * as fs from "fs";
+import yaml from "js-yaml";
+import validator from "is-my-json-valid";
+import extend from "extend";
+
+type Schema = any;
+
+export default class ConfigValidator {
+
+    /**
+     * Construct a validator of YAML files.
+     * @param schema The JSON schema file object.
+     */
+    constructor (private schema: Schema) { }
+
+    /**
+     * Validate the input config.
+     * @param inputConfig The input config file path (string) or
+     * parsed config (Object).
+     * @param defaultConfig The default config options.
+     * @return The input config with defaults applied.
+     * @throws On validation errors
+     */
+    public validate(inputConfig: string|Schema, defaultConfig: Record<string, unknown> = {}) {
+        if (typeof inputConfig === "string") {
+            inputConfig = ConfigValidator.loadFromFile(inputConfig);
+        }
+        const js = validator(this.schema, {
+            verbose: true,
+        });
+        const res = js(inputConfig, this.schema);
+        if (!res) {
+            js.errors.forEach(error => {
+                console.error(JSON.stringify(error));
+                console.error(`The field ${error.field} is ${error.value}` +
+                            ` which ${error.message}`);
+            });
+            // This is a bit awful, but it's how we return validation errors.
+            const e: any = new Error("Failed to validate file");
+            e._validationErrors = js.errors;
+            throw e;
+        }
+        // mux in the default config
+        return extend(true, defaultConfig, inputConfig);
+    }
+
+    private static loadFromFile(filename: string): Schema {
+        const result = yaml.safeLoad(fs.readFileSync(filename, 'utf8'));
+        if (typeof(result) !== "object") {
+            throw Error('Was expecting yaml as an object');
+        }
+        return result;
+    }
+
+    private static fromSchemaFile(filename: string): ConfigValidator {
+        return new ConfigValidator(ConfigValidator.loadFromFile(filename));
+    }
+}
+
+module.exports = ConfigValidator;

src/index.ts

@@ -27,6 +27,7 @@ export * from "./components/state-lookup";
 
 // Config and CLI
 export * from "./components/cli";
+export * from "./components/config-validator";
 module.exports.ConfigValidator = require("./components/config-validator");
 
 // Store