add error handling for async actions

app.js

@@ -29,93 +29,107 @@ app.post("/price", (req, res) => {
     }
 });
 
-app.get("/users/:userId/assets", async (req, res) => {
-    let irohaResponse = await fetchUsersAssets(req.params.userId);
+app.get("/users/:userId/assets", async (req, res, next) => {
+    try {
+        let irohaResponse = await fetchUsersAssets(req.params.userId);
 
-    res.status(irohaResponse.status);
+        res.status(irohaResponse.status);
 
-    if (irohaResponse.headers.get("content-length") < 1) {
-        res.send();
+        if (irohaResponse.headers.get("content-length") < 1) {
+            res.send();
+        }
+        else {
+            res.send(await irohaResponse.json());
+        }
     }
-    else {
-        res.send(await irohaResponse.json());
+    catch (err) {
+        next(err);
     }
 });
 
-app.get("/users/:userId/assets/:assetId", async (req, res) => {
-    let assets = (await fetchUsersAssets(req.params.userId)).assets;
-
-    let parsedAssetName = "";
-    let i = 0;
-    for (i; i < assets.length; i++) {
-        parsedAssetName = assets[i].assetId.split('#')[0];
-        if (parsedAssetName === req.params.assetId) {
-            res.status(200);
-            res.send(assets[i]);
-            return;
+app.get("/users/:userId/assets/:assetId", async (req, res, next) => {
+    try {
+        let assets = (await fetchUsersAssets(req.params.userId)).assets;
+
+        let parsedAssetName = "";
+        let i = 0;
+        for (i; i < assets.length; i++) {
+            parsedAssetName = assets[i].assetId.split('#')[0];
+            if (parsedAssetName === req.params.assetId) {
+                res.status(200);
+                res.send(assets[i]);
+                return;
+            }
         }
-    }
 
-    res.status(204);
-    res.send();
+        res.status(204);
+        res.send();
+    } catch (err) {
+        next(err);
+    }
 });
 
-app.post("/buy", async (req, res) => {
-
-    if (!req.body) {
-        res.status(400);
-        throw Error(JSON.stringify({ error: { name: "Error, request has no body!" } }));
-    }
+app.post("/buy", async (req, res, next) => {
 
-    if (!req.body.extent) {
-        res.status(400);
-        throw Error(JSON.stringify({ error: { name: "Error, request body has no \"extent\" property!" } }));
-    }
+    try {
+        if (!req.body) {
+            res.status(400);
+            throw Error(JSON.stringify({ error: { name: "Error, request has no body!" } }));
+        }
 
-    if (!req.body.user) {
-        res.status(400);
-        throw Error(JSON.stringify({ error: { name: "Error, request body has no \"user\" property!" } }));
-    }
+        if (!req.body.extent) {
+            res.status(400);
+            throw Error(JSON.stringify({ error: { name: "Error, request body has no \"extent\" property!" } }));
+        }
 
-    if (!req.body.privateKey) {
-        res.status(400);
-        throw Error(JSON.stringify({ error: { name: "Error, user must provide \"privateKey\" to sign transaction!" } }));
-    }
+        if (!req.body.user) {
+            res.status(400);
+            throw Error(JSON.stringify({ error: { name: "Error, request body has no \"user\" property!" } }));
+        }
 
-    let price = getPrice(req.body.extent);
+        if (!req.body.privateKey) {
+            res.status(400);
+            throw Error(JSON.stringify({ error: { name: "Error, user must provide \"privateKey\" to sign transaction!" } }));
+        }
 
-    let irohaResponse = await forwardBuyRequest(
-        {
-            privateKey: req.body.privateKey,
-            transfers: [
-                {
-                    asset: IROHA_ASSET + "#" + IROHA_DOMAIN,
-                    source: req.body.user + "@" + IROHA_DOMAIN,
-                    destination: DATA_OWNER + "@" + IROHA_DOMAIN,
-                    description: "test", //TODO: compose uniform description
-                    amount: price
-                }
-            ]
+        let price = getPrice(req.body.extent);
+
+        let irohaResponse = await forwardBuyRequest(
+            {
+                privateKey: req.body.privateKey,
+                transfers: [
+                    {
+                        asset: IROHA_ASSET + "#" + IROHA_DOMAIN,
+                        source: req.body.user + "@" + IROHA_DOMAIN,
+                        destination: DATA_OWNER + "@" + IROHA_DOMAIN,
+                        description: "test", //TODO: compose uniform description
+                        amount: price
+                    }
+                ]
+            }
+        );
+
+        let data = "test - to be implemented"; //TODO implement data extraction 
+
+        res.status(irohaResponse.status);
+
+        if (!irohaResponse.ok) {
+            res.send(await irohaResponse.json());
+            return;
         }
-    );
 
-    let data = "test - to be implemented"; //TODO implement data extraction 
+        let irohaResponseJson = await irohaResponse.json();
 
-    res.status(irohaResponse.status);
+        console.log("tx hash: " + irohaResponseJson.transactionHash);
 
-    if (!irohaResponse.ok) {
-        res.send(await irohaResponse.json());
-        return;
+        res.send({
+            data: data,
+            transactionHash: irohaResponseJson.transactionHash
+        });
+    }
+    catch (err) {
+        next(err);
     }
-
-    let irohaResponseJson = await irohaResponse.json();
-
-    console.log("tx hash: " + irohaResponseJson.transactionHash);   
-
-    res.send({
-        data : data,
-        transactionHash : irohaResponseJson.transactionHash
-    });
 });
 
 async function forwardBuyRequest(body) {
@@ -151,7 +165,7 @@ function getPrice(extent) {
 
 function error(err, req, res, next) { //TODO: add custom Exception class
     console.log(err);
-        res.status(500);
+    res.status(500);
     res.send(err.message);
 }