refactor: 🔨 don't crash main thread when the database file is corrupted

Add a lock for LocalData instance and throw error message while user trying modify package list

src/lib/storage/local/local-data.js

@@ -21,15 +21,13 @@ const logger = require('../../logger');
     try {
       dbFile = fs.readFileSync(this.path, 'utf8');
     } catch (err) {
-      if (err.code === 'ENOENT') { // Only recreate if file not found to prevent data loss
-        this.data = {list: []};
-      } else {
+      if (err.code !== 'ENOENT') { // Only recreate if file not found to prevent data loss
         logger.logger.error(
-          'Failed to read package database file, please check the error printed below and fix it manually:\n',
+          'Failed to read package database file, please check the error printed below:\n',
           `File Path: ${this.path}\n\n`,
           err
         );
-        throw new Error('Package database file unreachable');
+        this.locked = true; // Prevent any write action, wait admin to check what happened during startup
       }
     }
 
@@ -37,33 +35,39 @@ const logger = require('../../logger');
       try {
         this.data = JSON.parse(dbFile);
       } catch(err) {
-        logger.logger.error(err);
-        throw new Error(`Package database file corrupted (invalid JSON), please fix it manually.\nFile Path: ${this.path}`);
+        logger.logger.error(`Package database file corrupted (invalid JSON), please check the error printed below.\nFile Path: ${this.path}`, err);
+        this.locked = true;
       }
     }
+
+    if (!this.data) {
+      this.data = {list: []};
+    }
   }
 
   /**
    * Add a new element.
    * @param {*} name
+   * @return {Error|*}
    */
   add(name) {
     if (this.data.list.indexOf(name) === -1) {
       this.data.list.push(name);
-      this.sync();
+      return this.sync();
     }
   }
 
   /**
    * Remove an element from the database.
    * @param {*} name
+   * @return {Error|*}
    */
   remove(name) {
     const i = this.data.list.indexOf(name);
     if (i !== -1) {
       this.data.list.splice(i, 1);
     }
-    this.sync();
+    return this.sync();
   }
 
   /**
@@ -76,8 +80,14 @@ const logger = require('../../logger');
 
   /**
    * Syncronize {create} database whether does not exist.
+   * @return {Error|*}
    */
   sync() {
+    if (this.locked) {
+      logger.logger.error('Database is locked, please check error message printed during startup to prevent data loss.');
+      return new Error('Verdaccio database is locked, please contact your administrator to checkout logs during verdaccio startup.');
+    }
+
     // Uses sync to prevent ugly race condition
     try {
       require('mkdirp').sync(Path.dirname(this.path));
@@ -85,7 +95,11 @@ const logger = require('../../logger');
       // perhaps a logger instance?
       /* eslint no-empty:off */
     }
+    try {
       fs.writeFileSync(this.path, JSON.stringify(this.data));
+    } catch (err) {
+      return err;
+    }
   }
 
 }

src/lib/storage/local/local-storage.js

@@ -119,6 +119,12 @@ class LocalStorage {
       }
       this._normalizePackage(data);
 
+      let removeFailed = this.localList.remove(name);
+      if (removeFailed) {
+        // This will happen when database is locked
+        return callback(this.utils.ErrorCode.get422(removeFailed.message));
+      }
+
       storage.unlink(pkgFileName, function(err) {
         if (err) {
           return callback(err);
@@ -145,7 +151,6 @@ class LocalStorage {
         });
       });
     });
-    this.localList.remove(name);
   }
 
   /**
@@ -296,7 +301,12 @@ class LocalStorage {
 
       data.versions[version] = metadata;
       this.utils.tag_version(data, version, tag);
-      this.localList.add(name);
+
+      let addFailed = this.localList.add(name);
+      if (addFailed) {
+        return cb(this.utils.ErrorCode.get422(addFailed.message));
+      }
+
       cb();
     }, callback);
   }