Merge branch 'issue/49' into 'master'

Issue #49: Add error handling middleware

See merge request !41

src/api/middlewares/error.spec.ts

+/*
+ * Copyright (C) 2017 Centro de Computacao Cientifica e Software Livre
+ * Departamento de Informatica - Universidade Federal do Parana
+ *
+ * This file is part of blendb.
+ *
+ * blendb is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * blendb is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with blendb.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+import * as request from "supertest";
+import { expect } from "chai";
+
+import * as server from "../../main";
+
+describe("API error middleware", () => {
+
+    it("should respond 404 when a route does not exists", (done) => {
+        request(server)
+            .get("/v1/inexistent")
+            .expect(404)
+            .expect((res: any) => {
+                const error = "Cannot GET /v1/inexistent";
+                expect(res.body).to.be.an("object");
+                expect(res.body).to.have.property("error");
+                expect(res.body.error).to.be.eql(error);
+            })
+            .end(done);
+    });
+
+    it("should respond 400 for missing required parameters", (done) => {
+        request(server)
+            .get("/v1/data")
+            .query({metrics: "random"})
+            .expect(400)
+            .expect((res: any) => {
+                const error = "Bad request: Some problems with this request were found";
+                expect(res.body).to.be.an("object");
+                expect(res.body).to.have.property("error");
+                expect(res.body).to.have.property("requestErrors");
+                expect(res.body.error).to.be.eql(error);
+                expect(res.body.requestErrors).to.have.length(1);
+            })
+            .end(done);
+    });
+});

src/api/middlewares/error.ts

+/*
+ * Copyright (C) 2017 Centro de Computacao Cientifica e Software Livre
+ * Departamento de Informatica - Universidade Federal do Parana
+ *
+ * This file is part of blendb.
+ *
+ * blendb is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * blendb is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with blendb.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+import * as express from "express";
+
+export function ErrorMw(config: string): express.ErrorRequestHandler {
+    const handlers: { [key: string]: express.ErrorRequestHandler } = {
+        "v1": function(err, req, res, next) {
+            if (err.ramlNotFound) {
+                const splited = err.toString().split(" ");
+                const method = splited[1];
+                const route = "/v1" + splited[2];
+                res.status(404).json({ error: "Cannot " + method + " " + route });
+            }
+
+            else if (err.ramlValidation) {
+                res.status(400).json({
+                    error: "Bad request: Some problems with this request were found"
+                    , requestErrors: err.requestErrors
+                });
+            }
+
+            else if (err.ramlAuthorization) {
+                res.status(401).json({
+                    error: "Unauthorized: Some problems with your authentication were found, try to authenticate again"
+                    , requestErrors: err.authorizationErrors
+                });
+            }
+
+            else {
+                res.status(400).json({error: err.toString()});
+            }
+
+            return;
+        },
+
+        "default": function(err, req, res, next) {
+            next(err);
+            return;
+        }
+    };
+
+    if (handlers[config]) {
+        return handlers[config];
+    }
+
+    else {
+        return handlers.default;
+    }
+};

src/main.ts

@@ -39,6 +39,7 @@ const config = ConfigParser.parse(configPath);
 // include middlewares
 import { EngineMw } from "./api/middlewares/engine";
 import { PostgresMw } from "./api/middlewares/adapter";
+import { ErrorMw } from "./api/middlewares/error";
 
 app.use(EngineMw(config));
 app.use(PostgresMw(config.connection));
@@ -51,6 +52,8 @@ ramlParser.loadFile("specs/blendb-api-v1.raml")
             osprey.server(raml),
             router);
 
+        app.use("/v1", ErrorMw("v1"));
+
         let port = process.env.PORT || 3000;
         app.listen(port);