refactor to use ES6 template strings

replace string interp w/ templates in core

use string templating es6 in benchmarks

template strings in tests dir

benchmarks/experimental/async.js

@@ -10,7 +10,7 @@ app.experimental = true;
 // number of middleware
 
 const n = parseInt(process.env.MW || '1', 10);
-console.log('  %s async middleware', n);
+console.log(`  ${n} async middleware`);
 
 while (n--) {
   app.use(async function (next){

benchmarks/middleware.js

@@ -8,7 +8,7 @@ const app = koa();
 // number of middleware
 
 const n = parseInt(process.env.MW || '1', 10);
-console.log('  %s middleware', n);
+console.log(`  ${n} middleware`);
 
 while (n--) {
   app.use(function *(next){

lib/application.js

@@ -165,7 +165,7 @@ app.createContext = function(req, res){
  */
 
 app.onerror = function(err){
-  assert(err instanceof Error, 'non-error thrown: ' + err);
+  assert(err instanceof Error, `non-error thrown: ${err}`);
 
   if (404 == err.status || err.expose) return;
   if (this.silent) return;

lib/context.js

@@ -104,7 +104,7 @@ const proto = module.exports = {
     // to node-style callbacks.
     if (null == err) return;
 
-    if (!(err instanceof Error)) err = new Error('non-error thrown: ' + err);
+    if (!(err instanceof Error)) err = new Error(`non-error thrown: ${err}`);
 
     // delegate
     this.app.emit('error', err, this);

lib/request.js

@@ -69,7 +69,7 @@ module.exports = {
    */
 
   get origin() {
-    return this.protocol + '://' + this.host;
+    return `${this.protocol}://${this.host}`;
   },
 
   /**
@@ -196,7 +196,7 @@ module.exports = {
 
   get search() {
     if (!this.querystring) return '';
-    return '?' + this.querystring;
+    return `?${this.querystring}`;
   },
 
   /**

lib/response.js

@@ -80,7 +80,7 @@ module.exports = {
 
   set status(code) {
     assert('number' == typeof code, 'status code must be a number');
-    assert(statuses[code], 'invalid status code: ' + code);
+    assert(statuses[code], `invalid status code: ${code}`);
     this._explicitStatus = true;
     this.res.statusCode = code;
     this.res.statusMessage = statuses[code];
@@ -263,13 +263,13 @@ module.exports = {
     if (this.ctx.accepts('html')) {
       url = escape(url);
       this.type = 'text/html; charset=utf-8';
-      this.body = 'Redirecting to <a href="' + url + '">' + url + '</a>.';
+      this.body = `Redirecting to <a href="${url}">${url}</a>.`;
       return;
     }
 
     // text
     this.type = 'text/plain; charset=utf-8';
-    this.body = 'Redirecting to ' + url + '.';
+    this.body = `Redirecting to ${url}.`;
   },
 
   /**
@@ -344,7 +344,7 @@ module.exports = {
    */
 
   set etag(val) {
-    if (!/^(W\/)?"/.test(val)) val = '"' + val + '"';
+    if (!/^(W\/)?"/.test(val)) val = `"${val}"`;
     this.set('ETag', val);
   },
 

test/response/redirect.js

@@ -46,7 +46,7 @@ describe('ctx.redirect(url)', function(){
       ctx.header.accept = 'text/html';
       ctx.redirect(url);
       ctx.response.header['content-type'].should.equal('text/html; charset=utf-8');
-      ctx.body.should.equal('Redirecting to <a href="' + url + '">' + url + '</a>.');
+      ctx.body.should.equal(`Redirecting to <a href="${url}">${url}</a>.`);
     })
 
     it('should escape the url', function(){
@@ -56,7 +56,7 @@ describe('ctx.redirect(url)', function(){
       ctx.redirect(url);
       url = escape(url);
       ctx.response.header['content-type'].should.equal('text/html; charset=utf-8');
-      ctx.body.should.equal('Redirecting to <a href="' + url + '">' + url + '</a>.');
+      ctx.body.should.equal(`Redirecting to <a href="${url}">${url}</a>.`);
     })
   })
 
@@ -66,7 +66,7 @@ describe('ctx.redirect(url)', function(){
       const url = 'http://google.com';
       ctx.header.accept = 'text/plain';
       ctx.redirect(url);
-      ctx.body.should.equal('Redirecting to ' + url + '.');
+      ctx.body.should.equal(`Redirecting to ${url}.`);
     })
   })
 
@@ -78,7 +78,7 @@ describe('ctx.redirect(url)', function(){
       ctx.header.accept = 'text/plain';
       ctx.redirect('http://google.com');
       ctx.status.should.equal(301);
-      ctx.body.should.equal('Redirecting to ' + url + '.');
+      ctx.body.should.equal(`Redirecting to ${url}.`);
     })
   })
 
@@ -90,7 +90,7 @@ describe('ctx.redirect(url)', function(){
       ctx.header.accept = 'text/plain';
       ctx.redirect('http://google.com');
       ctx.status.should.equal(302);
-      ctx.body.should.equal('Redirecting to ' + url + '.');
+      ctx.body.should.equal(`Redirecting to ${url}.`);
     })
   })
 
@@ -102,7 +102,7 @@ describe('ctx.redirect(url)', function(){
       ctx.header.accept = 'text/plain';
       ctx.redirect('http://google.com');
       ctx.status.should.equal(302);
-      ctx.body.should.equal('Redirecting to ' + url + '.');
+      ctx.body.should.equal(`Redirecting to ${url}.`);
       ctx.type.should.equal('text/plain');
     })
   })