feat: grpc enhancements, validation bug fixes (#211)

* fix: lazy loading the validation modules #203 (#206)
* feat: state helper (#207)
* feat: cookie support for the capture helper (#209)
* implement basic error response and metadata. #188
* docs: grpc documentation
* fix: race condition with lazy loading of the validation adapters (#210)

docs/capture-helper.md

@@ -23,6 +23,10 @@ Example `{{capture using='jsonpath' selector='$.lastName'}}`
 
 Similar to websockets, while using `capture` helper with gRPC, available/required arguments are `using` and `selector`.
 
+Example `{{capture using='jsonpath' selector='$.lastName'}}`
+
 1. For unary calls and server side streams, helpers have access to request payload as is.
-2. For client side streaming calls, payloads from each stream are stored in an array, which is then made available to helpers.
-3. For bidi side streams, helpers can access the request payload as is during each streaming/ping-pong interaction i.e. while sending the "data" stream. Additionally, each payload is also stored in an array which is then made available to helpers while sending the "end" stream
+2. For unary calls and server side streams, helpers have access to metadata as well, which can be captured by specifying `key` and `from`.
+Example: `{{capture from='metadata' key='metadata_key'}}`
+3. For client side streaming calls, payloads from each stream are stored in an array, which is then made available to helpers.
+4. For bidi side streams, helpers can access the request payload as is during each streaming/ping-pong interaction i.e. while sending the "data" stream. Additionally, each payload is also stored in an array which is then made available to helpers while sending the "end" stream.

docs/handlebars.md

@@ -59,8 +59,9 @@ Usage:
 }
 ```
 
-2. **{{capture from='path' regex='\/users\/get\/(.*)?'}}** - For path, you'd need to specify a regex to capture a value.
-3. **{{capture from='body' using='jsonpath' selector='$.lastName'}}** - To capture values from the request body, your options are either using='regex' or using='jsonpath'. Selector will change accordingly.
+2. **{{capture from='cookies' key='mycookie'}}** - For cookies, you'd need to specify a key to capture a value.
+3. **{{capture from='path' regex='\/users\/get\/(.*)?'}}** - For path, you'd need to specify a regex to capture a value.
+4. **{{capture from='body' using='jsonpath' selector='$.lastName'}}** - To capture values from the request body, your options are either using='regex' or using='jsonpath'. Selector will change accordingly.
 
 !!!note
 

docs/mocking-gRPC.md

@@ -107,6 +107,32 @@ You can also add delays in your grpc mock services, by adding a delay key with t
 
 You don't need to modify your proto file to accommodate the additional key, since Camouflage will delete the "delay" key from the response before sending it to the client.
 
+## Sending GRPC Error responses
+
+Camouflage provides an experimental support to send error responses starting v0.11.0 onwards, for unary and client side streaming calls. To send an error response, append a json error object with `code` and optional `message` to your mock content.
+
+```json
+{
+  "error": {
+    "code": 16,
+    "message": "User is unauthenticted."
+  }
+}
+```
+
+## Sending GRPC response metadata
+
+Camouflage provides an experimental support to send metadata/trailers with responses starting v0.11.0 onwards, for unary and client side streaming calls. To send metadata, append a json metadata object with relevant keys and values to your mock content.
+
+```json
+{
+  "metadata": {
+    "key1": "value1",
+    "key2": "value2"
+  }
+}
+```
+
 !!!caution
 
     Since the Camouflage gRPC server needs to register the new services, everytime you add a new protofile, you'd need to restart the Camouflage server. Good news is, you can do so easily by making a get request to /restart endpoint. Though the downtime is minimal (less than a second, we do not recommend restarting the server during a performance test. Note that restart is required only if you add a new protofile. If you have added a new mock file or updated an existing one, a restart is not required.

grpc/mocks/blogPackage/BlogService/createBlog.mock

@@ -1,4 +1,12 @@
 {
     "id": {{num_between lower=500 upper=600}},
-    "title": "something"
+    "title": "something",
+    "error": {
+        "code": 16,
+        "message": "User is unauthenticated."
+    },
+    "metadata": {
+        "key1": "value1",
+        "key2": "value2"
+    }
 }

mocks/capture/cookies/GET.mock

@@ -0,0 +1,12 @@
+HTTP/1.1 200 OK
+Content-Type: application/json
+
+{{#if (capture from='cookies' key='scenario') }}
+{
+    "scenario": "{{capture from='cookies' key='scenario'}}"
+}
+{{else}}
+{
+    "scenario": "no cookie found for scenario"
+}
+{{/if}}

package.json

@@ -47,6 +47,7 @@
     "apicache": "^1.6.3",
     "compression": "^1.7.4",
     "convert-csv-to-json": "^1.3.3",
+    "cookie-parser": "^1.4.6",
     "cors": "^2.8.5",
     "express": "^4.18.1",
     "express-query-parser": "^1.3.3",
@@ -76,6 +77,7 @@
     "yargs": "^16.2.0"
   },
   "devDependencies": {
+    "@types/cookie-parser": "^1.4.3",
     "@types/express": "^4.17.11",
     "@types/http-errors": "^1.8.2",
     "@types/js-yaml": "^4.0.5",

src/handlebar/RequestHelper.ts

@@ -14,7 +14,7 @@ export class RequestHelper {
    * Registers capture helper
    * - Get the request object passed in from the context by calling template({request: req})
    * - Get the from value passed in while calling {{capture from=}}, accepted values query, headers, path, body
-   * - For query and headers, key is required, else if not found a null/undefined value will be automatically returned.
+   * - For query, cookies and headers, key is required, else if not found a null/undefined value will be automatically returned.
    * - For path additional input regex is mandatory, if not passed return error
    * - For body additional inputs using and selector are mandatory, if not passed return error
    * @returns {void}
@@ -28,6 +28,8 @@ export class RequestHelper {
           return request.query[context.hash.key];
         case "headers":
           return request.get(context.hash.key);
+        case "cookies":
+          return request.cookies[context.hash.key] || "";
         case "path":
           if (typeof context.hash.regex === "undefined") {
             logger.debug("ERROR: No regex specified");

src/handlebar/StateHelper.ts

@@ -32,10 +32,9 @@ export class StateHelper {
    */
   register = () => {
     this.Handlebars.registerHelper("state", (context: any) => {
-      const cookie = context.data.root.request.headers.cookie;
-      const key = context.hash.key;
-      const value = new RegExp(`mocked-state-${key}=([^;]+)`).exec(cookie);
-      return value ? value[1] : context.fn(this);
+      const cookies = context.data.root.request.cookies || {};
+      const key = `mocked-state-${context.hash.key}`;
+      return cookies[key] || context.fn(this);
     });
   };
 }

src/index.ts

@@ -19,12 +19,12 @@ import swStats from "swagger-stats";
 import cors from "cors";
 import compression from "compression";
 import { queryParser } from "express-query-parser";
+import cookieParser from "cookie-parser";
 import ConfigLoader, {
   getLoaderInstance,
   setLoaderInstance,
 } from "./ConfigLoader";
 import { CamouflageConfig } from "./ConfigLoader/LoaderInterface";
-import { Validation } from "./validation";
 
 const app = express();
 // Configure logging for express requests
@@ -64,6 +64,8 @@ app.use(
     parseNumber: true,
   })
 );
+// parse cookies
+app.use(cookieParser());
 /**
  * Initializes required variables and starts a 1 master X workers configuration - FUTURE IMPROVEMENT - Pass a single config object
  * @param {string[]} protoIgnore array of files to be ignored during loading proto files

src/parser/GrpcParser.ts

@@ -6,6 +6,7 @@ import { getHandlebars } from '../handlebar'
 import { getLoaderInstance } from "../ConfigLoader";
 import { CamouflageConfig } from "../ConfigLoader/LoaderInterface";
 const Handlebars = getHandlebars()
+import * as grpc from "@grpc/grpc-js";
 /**
  * Parser class for GRPC Protocol mocks to define handlers for:
  * - Unary calls
@@ -42,16 +43,26 @@ export default class GrpcParser {
         const response = JSON.parse(fileContent);
         const delay: number = response.delay || 0;
         delete response.delay;
+        const error = response.error || null
+        delete response.error;
+        const metadata = response.metadata || null;
+        delete response.metadata;
+        const trailers = new grpc.Metadata();
+        if (metadata) {
+          for (const key in metadata) {
+            trailers.add(key, metadata[key])
+          }
+        }
         setTimeout(() => {
-          callback(null, response);
+          callback(error, response, trailers);
         }, delay);
       } else {
         logger.error(`No suitable mock file was found for ${mockFilePath}`);
-        callback(null, { error: `No suitable mock file was found for ${mockFilePath}` });
+        callback({ code: 5, message: `No suitable mock file was found for ${mockFilePath}` }, {});
       }
     } catch (error) {
       logger.error(error);
-      callback(null, { error: error });
+      callback({ code: 10, message: error }, {});
     }
   };
   /**
@@ -137,16 +148,26 @@ export default class GrpcParser {
           const response = JSON.parse(fileContent);
           const delay: number = response.delay || 0;
           delete response.delay;
+          const error = response.error || null;
+          delete response.error
+          const metadata = response.metadata || null;
+          delete response.metadata;
+          const trailers = new grpc.Metadata();
+          if (metadata) {
+            for (const key in metadata) {
+              trailers.add(key, metadata[key])
+            }
+          }
           setTimeout(() => {
-            callback(null, response);
+            callback(error, response, trailers);
           }, delay);
         } else {
           logger.error(`No suitable mock file was found for ${mockFilePath}`);
-          callback(null, { error: `No suitable mock file was found for ${mockFilePath}` });
+          callback({ code: 5, error: `No suitable mock file was found for ${mockFilePath}` }, {});
         }
       } catch (error) {
         logger.error(error);
-        callback(null, { error: error });
+        callback({ code: 10, message: error }, {});
       }
     });
   };

src/validation/ValidationAdapter.ts

@@ -13,7 +13,6 @@ export abstract class ValidationAdapter {
 
   constructor(config: ValidationSchema) {
     this.config = config;
-    this.load();
   }
 
   abstract load(): Promise<void>;

src/validation/index.ts

@@ -41,14 +41,17 @@ export class Validation {
     }
   }
 
-  private loadSchemas(schemas: ValidationSchema[]) {
+  private async loadSchemas(schemas: ValidationSchema[]) {
     for (let x = 0; x < schemas.length; x++) {
       const schema = schemas[x];
       // for now only OpenApi json schemas are supported
       // in the future more types can be added like xml-rpc
       switch (schema.type) {
         case ValidationSchemaType.OpenApi:
-          this.adapters.push(new OpenApiAdapter(schema));
+          // eslint-disable-next-line no-case-declarations
+          const adapter = new OpenApiAdapter(schema);
+          await adapter.load();
+          this.adapters.push(adapter);
           break;
         default:
           logger.warn(