(#8612) - use const where possible

Author: lucidNTR

packages/node_modules/pouchdb-adapter-http/src/index.js

@@ -35,16 +35,16 @@ const MAX_SIMULTANEOUS_REVS = 50;
 const CHANGES_TIMEOUT_BUFFER = 5000;
 const DEFAULT_HEARTBEAT = 10000;
 
-let supportsBulkGetMap = {};
+const supportsBulkGetMap = {};
 
 function readAttachmentsAsBlobOrBuffer(row) {
-  let doc = row.doc || row.ok;
-  let atts = doc && doc._attachments;
+  const doc = row.doc || row.ok;
+  const atts = doc && doc._attachments;
   if (!atts) {
     return;
   }
   Object.keys(atts).forEach(function (filename) {
-    let att = atts[filename];
+    const att = atts[filename];
     att.data = b64StringToBluffer(att.data, att.content_type);
   });
 }
@@ -65,7 +65,7 @@ function preprocessAttachments(doc) {
   }
 
   return Promise.all(Object.keys(doc._attachments).map(function (key) {
-    let attachment = doc._attachments[key];
+    const attachment = doc._attachments[key];
     if (attachment.data && typeof attachment.data !== 'string') {
       return new Promise(function (resolve) {
         blufferToBase64(attachment.data, resolve);
@@ -80,7 +80,7 @@ function hasUrlPrefix(opts) {
   if (!opts.prefix) {
     return false;
   }
-  let protocol = parseUri(opts.prefix).protocol;
+  const protocol = parseUri(opts.prefix).protocol;
   return protocol === 'http' || protocol === 'https';
 }
 
@@ -89,20 +89,20 @@ function hasUrlPrefix(opts) {
 function getHost(name, opts) {
   // encode db name if opts.prefix is a url (#5574)
   if (hasUrlPrefix(opts)) {
-    let dbName = opts.name.substr(opts.prefix.length);
+    const dbName = opts.name.substr(opts.prefix.length);
     // Ensure prefix has a trailing slash
-    let prefix = opts.prefix.replace(/\/?$/, '/');
+    const prefix = opts.prefix.replace(/\/?$/, '/');
     name = prefix + encodeURIComponent(dbName);
   }
 
-  let uri = parseUri(name);
+  const uri = parseUri(name);
   if (uri.user || uri.password) {
     uri.auth = {username: uri.user, password: uri.password};
   }
 
   // Split the path part of the URI into parts using '/' as the delimiter
   // after removing any leading '/' and any trailing '/'
-  let parts = uri.path.replace(/(^\/|\/$)/g, '').split('/');
+  const parts = uri.path.replace(/(^\/|\/$)/g, '').split('/');
 
   uri.db = parts.pop();
   // Prevent double encoding of URI component
@@ -124,7 +124,7 @@ function genDBUrl(opts, path) {
 function genUrl(opts, path) {
   // If the host already has a path, then we need to have a path delimiter
   // Otherwise, the path delimiter is the empty string
-  let pathDel = !opts.path ? '' : '/';
+  const pathDel = !opts.path ? '' : '/';
 
   // If the host already has a path, then we need to have a path delimiter
   // Otherwise, the path delimiter is the empty string
@@ -140,23 +140,23 @@ function paramsToStr(params) {
 }
 
 function shouldCacheBust(opts) {
-  let ua = (typeof navigator !== 'undefined' && navigator.userAgent) ?
+  const ua = (typeof navigator !== 'undefined' && navigator.userAgent) ?
       navigator.userAgent.toLowerCase() : '';
-  let isIE = ua.indexOf('msie') !== -1;
-  let isTrident = ua.indexOf('trident') !== -1;
-  let isEdge = ua.indexOf('edge') !== -1;
-  let isGET = !('method' in opts) || opts.method === 'GET';
+  const isIE = ua.indexOf('msie') !== -1;
+  const isTrident = ua.indexOf('trident') !== -1;
+  const isEdge = ua.indexOf('edge') !== -1;
+  const isGET = !('method' in opts) || opts.method === 'GET';
   return (isIE || isTrident || isEdge) && isGET;
 }
 
 // Implements the PouchDB API for dealing with CouchDB instances over HTTP
 function HttpPouch(opts, callback) {
 
   // The functions that will be publicly available for HttpPouch
-  let api = this;
+  const api = this;
 
-  let host = getHost(opts.name, opts);
-  let dbUrl = genDBUrl(host, '');
+  const host = getHost(opts.name, opts);
+  const dbUrl = genDBUrl(host, '');
 
   opts = clone(opts);
 
@@ -168,13 +168,13 @@ function HttpPouch(opts, callback) {
     options.credentials = 'include';
 
     if (opts.auth || host.auth) {
-      let nAuth = opts.auth || host.auth;
-      let str = nAuth.username + ':' + nAuth.password;
-      let token = btoa(unescape(encodeURIComponent(str)));
+      const nAuth = opts.auth || host.auth;
+      const str = nAuth.username + ':' + nAuth.password;
+      const token = btoa(unescape(encodeURIComponent(str)));
       options.headers.set('Authorization', 'Basic ' + token);
     }
 
-    let headers = opts.headers || {};
+    const headers = opts.headers || {};
     Object.keys(headers).forEach(function (key) {
       options.headers.append(key, headers[key]);
     });
@@ -184,7 +184,7 @@ function HttpPouch(opts, callback) {
       url += (url.indexOf('?') === -1 ? '?' : '&') + '_nonce=' + Date.now();
     }
 
-    let fetchFun = opts.fetch || fetch;
+    const fetchFun = opts.fetch || fetch;
     return await fetchFun(url, options);
   };
 
@@ -193,15 +193,15 @@ function HttpPouch(opts, callback) {
       setup().then(function () {
         return fun.apply(this, args);
       }).catch(function (e) {
-        let callback = args.pop();
+        const callback = args.pop();
         callback(e);
       });
     }).bind(api);
   }
 
   async function fetchJSON(url, options) {
 
-    let result = {};
+    const result = {};
 
     options = options || {};
     options.headers = options.headers || new Headers();
@@ -221,7 +221,7 @@ function HttpPouch(opts, callback) {
     result.data = json;
     if (!result.ok) {
       result.data.status = result.status;
-      let err = generateErrorFromResponse(result.data);
+      const err = generateErrorFromResponse(result.data);
       throw err;
     }
 
@@ -298,7 +298,7 @@ function HttpPouch(opts, callback) {
     }
 
     // Bad response or missing `uuid` should not prevent ID generation.
-    let uuid = (result && result.uuid) ? (result.uuid + host.db) : genDBUrl(host, '');
+    const uuid = (result && result.uuid) ? (result.uuid + host.db) : genDBUrl(host, '');
     callback(null, uuid);
   });
 
@@ -330,10 +330,10 @@ function HttpPouch(opts, callback) {
   });
 
   api.bulkGet = coreAdapterFun('bulkGet', function (opts, callback) {
-    let self = this;
+    const self = this;
 
     async function doBulkGet(cb) {
-      let params = {};
+      const params = {};
       if (opts.revs) {
         params.revs = true;
       }
@@ -364,10 +364,10 @@ function HttpPouch(opts, callback) {
     /* istanbul ignore next */
     function doBulkGetShim() {
       // avoid "url too long error" by splitting up into multiple requests
-      let batchSize = MAX_SIMULTANEOUS_REVS;
-      let numBatches = Math.ceil(opts.docs.length / batchSize);
+      const batchSize = MAX_SIMULTANEOUS_REVS;
+      const numBatches = Math.ceil(opts.docs.length / batchSize);
       let numDone = 0;
-      let results = new Array(numBatches);
+      const results = new Array(numBatches);
 
       function onResult(batchNum) {
         return function (err, res) {
@@ -380,16 +380,16 @@ function HttpPouch(opts, callback) {
       }
 
       for (let i = 0; i < numBatches; i++) {
-        let subOpts = pick(opts, ['revs', 'attachments', 'binary', 'latest']);
+        const subOpts = pick(opts, ['revs', 'attachments', 'binary', 'latest']);
         subOpts.docs = opts.docs.slice(i * batchSize,
           Math.min(opts.docs.length, (i + 1) * batchSize));
         bulkGetShim(self, subOpts, onResult(i));
       }
     }
 
     // mark the whole database as either supporting or not supporting _bulk_get
-    let dbUrl = genUrl(host, '');
-    let supportsBulkGet = supportsBulkGetMap[dbUrl];
+    const dbUrl = genUrl(host, '');
+    const supportsBulkGet = supportsBulkGetMap[dbUrl];
 
     /* istanbul ignore next */
     if (typeof supportsBulkGet !== 'boolean') {
@@ -450,7 +450,7 @@ function HttpPouch(opts, callback) {
     opts = clone(opts);
 
     // List of parameters to add to the GET request
-    let params = {};
+    const params = {};
 
     if (opts.revs) {
       params.revs = true;
@@ -487,8 +487,8 @@ function HttpPouch(opts, callback) {
     id = encodeDocId(id);
 
     function fetchAttachments(doc) {
-      let atts = doc._attachments;
-      let filenames = atts && Object.keys(atts);
+      const atts = doc._attachments;
+      const filenames = atts && Object.keys(atts);
       if (!atts || !filenames.length) {
         return;
       }
@@ -513,7 +513,7 @@ function HttpPouch(opts, callback) {
 
         let data;
         if (opts.binary) {
-          let typeFieldDescriptor = Object.getOwnPropertyDescriptor(blob.__proto__, 'type');
+          const typeFieldDescriptor = Object.getOwnPropertyDescriptor(blob.__proto__, 'type');
           if (!typeFieldDescriptor || typeFieldDescriptor.set) {
             blob.type = att.content_type;
           }
@@ -529,7 +529,7 @@ function HttpPouch(opts, callback) {
         att.data = data;
       }
 
-      let promiseFactories = filenames.map(function (filename) {
+      const promiseFactories = filenames.map(function (filename) {
         return function () {
           return fetchData(filename);
         };
@@ -634,7 +634,7 @@ function HttpPouch(opts, callback) {
 
       // TODO: also remove
       if (typeof process !== 'undefined' && !process.browser) {
-        var typeFieldDescriptor = Object.getOwnPropertyDescriptor(blob.__proto__, 'type');
+        const typeFieldDescriptor = Object.getOwnPropertyDescriptor(blob.__proto__, 'type');
         if (!typeFieldDescriptor || typeFieldDescriptor.set) {
           blob.type = contentType;
         }
@@ -761,7 +761,7 @@ function HttpPouch(opts, callback) {
     opts = clone(opts);
 
     // List of parameters to add to the GET request
-    let params = {};
+    const params = {};
     let body;
     let method = 'GET';
 
@@ -819,7 +819,7 @@ function HttpPouch(opts, callback) {
       params.skip = opts.skip;
     }
 
-    let paramStr = paramsToStr(params);
+    const paramStr = paramsToStr(params);
 
     if (typeof opts.keys !== 'undefined') {
       method = 'POST';
@@ -849,7 +849,7 @@ function HttpPouch(opts, callback) {
     // if there is a large set of changes to be returned we can start
     // processing them quicker instead of waiting on the entire
     // set of changes to return and attempting to process them at once
-    let batchSize = 'batch_size' in opts ? opts.batch_size : CHANGES_BATCH_SIZE;
+    const batchSize = 'batch_size' in opts ? opts.batch_size : CHANGES_BATCH_SIZE;
 
     opts = clone(opts);
 
@@ -871,12 +871,12 @@ function HttpPouch(opts, callback) {
         requestTimeout = opts.heartbeat + CHANGES_TIMEOUT_BUFFER;
     }
 
-    let params = {};
+    const params = {};
     if ('timeout' in opts && opts.timeout) {
       params.timeout = opts.timeout;
     }
 
-    let limit = (typeof opts.limit !== 'undefined') ? opts.limit : false;
+    const limit = (typeof opts.limit !== 'undefined') ? opts.limit : false;
     let leftToFetch = limit;
 
     if (opts.style) {
@@ -931,7 +931,7 @@ function HttpPouch(opts, callback) {
     // If opts.query_params exists, pass it through to the changes request.
     // These parameters may be used by the filter on the source database.
     if (opts.query_params && typeof opts.query_params === 'object') {
-      for (let param_name in opts.query_params) {
+      for (const param_name in opts.query_params) {
         /* istanbul ignore else */
         if (Object.prototype.hasOwnProperty.call(opts.query_params, param_name)) {
           params[param_name] = opts.query_params[param_name];
@@ -957,7 +957,7 @@ function HttpPouch(opts, callback) {
       body = {selector: opts.selector };
     }
 
-    let controller = new AbortController();
+    const controller = new AbortController();
     let lastFetchedSeq;
 
     // Get all the changes starting wtih the one immediately after the
@@ -983,8 +983,8 @@ function HttpPouch(opts, callback) {
       }
 
       // Set the options for the ajax call
-      let url = genDBUrl(host, '_changes' + paramsToStr(params));
-      let fetchOpts = {
+      const url = genDBUrl(host, '_changes' + paramsToStr(params));
+      const fetchOpts = {
         signal: controller.signal,
         method: method,
         body: JSON.stringify(body)
@@ -1009,7 +1009,7 @@ function HttpPouch(opts, callback) {
     // If opts.since exists, get all the changes from the sequence
     // number given by opts.since. Otherwise, get all the changes
     // from the sequence number 0.
-    let results = {results: []};
+    const results = {results: []};
 
     const fetched = function (err, res) {
       if (opts.aborted) {
@@ -1031,11 +1031,11 @@ function HttpPouch(opts, callback) {
           lastSeq = results.last_seq;
         }
         // For each change
-        let req = {};
+        const req = {};
         req.query = opts.query_params;
         res.results = res.results.filter(function (c) {
           leftToFetch--;
-          let ret = filterChange(opts)(c);
+          const ret = filterChange(opts)(c);
           if (ret) {
             if (opts.include_docs && opts.attachments && opts.binary) {
               readAttachmentsAsBlobOrBuffer(c);
@@ -1061,7 +1061,7 @@ function HttpPouch(opts, callback) {
         lastFetchedSeq = res.last_seq;
       }
 
-      let finished = (limit && leftToFetch <= 0) ||
+      const finished = (limit && leftToFetch <= 0) ||
         (res && raw_results_length < batchSize) ||
         (opts.descending);