refactor: modify provider service to Promise-based

packages/concordia-contracts-provider/package.json

@@ -12,6 +12,7 @@
     "cors": "^2.8.5",
     "esm": "~3.2.25",
     "express": "^4.17.1",
+    "express-async-handler": "^1.1.4",
     "lodash": "^4.17.20",
     "multer": "^1.4.2",
     "multiparty": "^4.2.2"

packages/concordia-contracts-provider/src/controllers/download.js

@@ -1,31 +1,38 @@
-import * as fs from 'fs';
+import { promises as fs } from 'fs';
 import path from 'path';
 import { getStorageLocation, getTagsDirectory } from '../utils/storageUtils';
 
-const downloadContracts = async (req, res) => {
-  const { params: { hash: hashOrTag } } = req;
-  let directoryPath = getStorageLocation(hashOrTag);
-
-  if (!fs.existsSync(directoryPath)) {
-    const tagsDirectory = getTagsDirectory();
-
-    if (fs.existsSync(tagsDirectory)) {
-      const tagFilePath = path.join(tagsDirectory, hashOrTag);
-      const tagReference = fs.readFileSync(tagFilePath, 'utf-8');
-
-      directoryPath = getStorageLocation(tagReference);
-    }
-  }
+const readContractFilesToArray = (contractsDirectoryPath) => fs
+  .readdir(contractsDirectoryPath)
+  .then((contractFilenames) => contractFilenames
+    .map((contractFilename) => fs
+      .readFile(path.join(`${contractsDirectoryPath}/${contractFilename}`), 'utf-8')
+      .then((rawContractData) => JSON.parse(rawContractData))))
+  .then((contractObjectPromises) => Promise.all([...contractObjectPromises]));
 
-  const contracts = [];
-
-  fs.readdirSync(directoryPath).forEach((contractFilename) => {
-    const rawContractData = fs.readFileSync(path.join(`${directoryPath}/${contractFilename}`), 'utf-8');
-    const contractJson = JSON.parse(rawContractData);
-    contracts.push(contractJson);
-  });
-
-  res.send(contracts);
+const downloadContracts = async (req, res) => {
+  const { params: { hash: identifier } } = req;
+  const hashBasedDirectoryPath = getStorageLocation(identifier);
+
+  return fs.access(hashBasedDirectoryPath)
+    .then(() => readContractFilesToArray(hashBasedDirectoryPath))
+    .catch(() => {
+      const tagsDirectory = getTagsDirectory();
+
+      return fs
+        .access(tagsDirectory)
+        .then(() => {
+          const tagFilePath = path.join(tagsDirectory, identifier);
+
+          return fs.readFile(tagFilePath, 'utf-8')
+            .then((tagReference) => {
+              const tagBasedDirectoryPath = getStorageLocation(tagReference);
+
+              return readContractFilesToArray(tagBasedDirectoryPath);
+            });
+        });
+    }).then((contracts) => res.send(contracts))
+    .catch(() => Promise.reject(new Error(`No contracts version or tag found for ${identifier}.`)));
 };
 
 export default downloadContracts;

packages/concordia-contracts-provider/src/controllers/upload.js

@@ -1,5 +1,5 @@
 import path from 'path';
-import fs from 'fs';
+import { promises as fs } from 'fs';
 import upload from '../middleware/upload';
 import { getTagsDirectory } from '../utils/storageUtils';
 
@@ -7,31 +7,26 @@ const addOrTransferTag = (tag, hash) => {
   const tagsDirectory = getTagsDirectory();
   const tagFilePath = path.join(tagsDirectory, tag);
 
-  fs.mkdirSync(tagsDirectory, { recursive: true });
-  fs.writeFileSync(tagFilePath, hash);
+  return fs
+    .mkdir(tagsDirectory, { recursive: true })
+    .then(() => fs.writeFile(tagFilePath, hash, 'utf-8'));
 };
 
-const uploadContracts = async (req, res) => {
-  try {
-    await upload(req, res);
+const uploadContracts = async (req, res) => upload(req, res)
+  .then(() => {
+    if (req.files.length <= 0) {
+      return Promise.reject(new Error('You must select at least 1 file.'));
+    }
 
     const { body: { tag } } = req;
     const { params: { hash } } = req;
 
     if (tag) {
-      addOrTransferTag(tag, hash);
-    }
-
-    if (req.files.length <= 0) {
-      return res.send('You must select at least 1 file.');
+      return addOrTransferTag(tag, hash)
+        .then(() => res.send('Files have been uploaded and tagged.'));
     }
 
     return res.send('Files have been uploaded.');
-  } catch (error) {
-    console.log(error);
-
-    return res.send(`Error when trying upload many files: ${error}`);
-  }
-};
+  });
 
 export default uploadContracts;

packages/concordia-contracts-provider/src/middleware/upload.js

@@ -16,7 +16,7 @@ const storage = multer.diskStorage({
 
     if (match.indexOf(file.mimetype) === -1) {
       const message = `<strong>${file.originalname}</strong> is invalid. Only JSON files are accepted.`;
-      return callback(message, null);
+      callback(message, null);
     }
 
     const filename = `${file.originalname}`;

packages/concordia-contracts-provider/src/routes/web.js

@@ -1,12 +1,13 @@
 import express from 'express';
+import asyncHandler from 'express-async-handler';
 import downloadContracts from '../controllers/download';
 import uploadContracts from '../controllers/upload';
 
 const router = express.Router();
 
 const routes = (app) => {
-  router.get('/contracts/:hash', downloadContracts);
-  router.post('/contracts/:hash', uploadContracts);
+  router.get('/contracts/:hash', asyncHandler(downloadContracts));
+  router.post('/contracts/:hash', asyncHandler(uploadContracts));
 
   return app.use('/', router);
 };

yarn.lock

@@ -6638,6 +6638,11 @@ explain-error@^1.0.4:
   resolved "https://registry.yarnpkg.com/explain-error/-/explain-error-1.0.4.tgz#a793d3ac0cad4c6ab571e9968fbbab6cb2532929"
   integrity sha1-p5PTrAytTGq1cemWj7urbLJTKSk=
 
+express-async-handler@^1.1.4:
+  version "1.1.4"
+  resolved "https://registry.yarnpkg.com/express-async-handler/-/express-async-handler-1.1.4.tgz#225a84908df63b35ae9df94b6f0f1af061266426"
+  integrity sha512-HdmbVF4V4w1q/iz++RV7bUxIeepTukWewiJGkoCKQMtvPF11MLTa7It9PRc/reysXXZSEyD4Pthchju+IUbMiQ==
+
 express@^4.14.0, express@^4.17.1:
   version "4.17.1"
   resolved "https://registry.yarnpkg.com/express/-/express-4.17.1.tgz#4491fc38605cf51f8629d39c2b5d026f98a4c134"