feat(config): add nocache option for file patterns

nmalaguti · nmalaguti · commit 6ef7e7b1546f · 2015-06-01T16:10:33.000-04:00
Add nocache property for file patterns in the config file.
This allows files that should be served by the webserver but that
don't need to be preprocessed but that should to be served fresh
(e.g. map files, pre-transpiled source built by other build process)
without a large amount of watches.
diff --git a/docs/config/02-files.md b/docs/config/02-files.md
@@ -41,6 +41,11 @@ Each pattern is either a simple string or an object with four properties:
 * **Default.** `true`
 * **Description.** Should the files be served by Karma's webserver?
 
+### `nocache`
+* **Type.** Boolean
+* **Default.** `false`
+* **Description.** Should the files be served from disk on each request by Karma's webserver?
+
 
 ## Preprocessor transformations
 Depending on preprocessor configuration, be aware that files loaded may be transformed and no longer available in
@@ -62,7 +67,10 @@ files: [
   {pattern: 'compiled/index.html', watched: false},
 
   // this file only gets watched and is otherwise ignored
-  {pattern: 'app/index.html', included: false, served: false}
+  {pattern: 'app/index.html', included: false, served: false},
+
+  // this file will be served on demand from disk and will be ignored by the watcher
+  {pattern: 'compiled/app.js.map', included: false, served: true, watched: false, nocache: true}
 ],
 ```
 
@@ -73,7 +81,7 @@ Example for loading images
 
 ```javascript
 files: [
-  {pattern: "test/images/*.jpg", watched: false, included: false, served: true}
+  {pattern: 'test/images/*.jpg', watched: false, included: false, served: true, nocache: false}
 ],
 ```
 
diff --git a/lib/config.js b/lib/config.js
@@ -22,15 +22,16 @@ try {
   LIVE_SCRIPT_AVAILABLE = true;
 } catch (e) {}
 
-var Pattern = function(pattern, served, included, watched) {
+var Pattern = function(pattern, served, included, watched, nocache) {
   this.pattern = pattern;
   this.served = helper.isDefined(served) ? served : true;
   this.included = helper.isDefined(included) ? included : true;
   this.watched = helper.isDefined(watched) ? watched : true;
+  this.nocache = helper.isDefined(nocache) ? nocache : false;
 };
 
 var UrlPattern = function(url) {
-  Pattern.call(this, url, false, true, false);
+  Pattern.call(this, url, false, true, false, false);
 };
 
 
@@ -43,15 +44,20 @@ var createPatternObject = function(pattern) {
     if (pattern.pattern && helper.isString(pattern.pattern)) {
       return helper.isUrlAbsolute(pattern.pattern) ?
         new UrlPattern(pattern.pattern) :
-        new Pattern(pattern.pattern, pattern.served, pattern.included, pattern.watched);
+        new Pattern(
+          pattern.pattern,
+          pattern.served,
+          pattern.included,
+          pattern.watched,
+          pattern.nocache);
     }
 
     log.warn('Invalid pattern %s!\n\tObject is missing "pattern" property.', pattern);
-    return new Pattern(null, false, false, false);
+    return new Pattern(null, false, false, false, false);
   }
 
   log.warn('Invalid pattern %s!\n\tExpected string or object with "pattern" property.', pattern);
-  return new Pattern(null, false, false, false);
+  return new Pattern(null, false, false, false, false);
 };
 
 
diff --git a/lib/file_list.js b/lib/file_list.js
@@ -32,6 +32,8 @@ var File = function(path, mtime) {
 
   this.mtime = mtime;
   this.isUrl = false;
+
+  this.doNotCache = false;
 };
 
 var Url = function(path) {
@@ -102,6 +104,10 @@ var List = function(patterns, excludes, emitter, preprocess, batchInterval) {
             files.included.push(file);
           }
 
+          if (patterns[idx].nocache) {
+            file.doNotCache = true;
+          }
+
           uniqueMap[file.path] = true;
         }
       });
@@ -216,15 +222,24 @@ var List = function(patterns, excludes, emitter, preprocess, batchInterval) {
                 // TODO(vojta): reuse file objects
                 var file = new File(path, stat.mtime);
 
-                preprocess(file, function(err) {
-                  buckets[i].push(file);
+                if (patternObject.nocache) {
+                  log.debug('Not preprocessing "%s" due to nocache', path);
 
-                  if (err) {
-                    addError(path);
-                  }
+                  file.doNotCache = true;
+                  buckets[i].push(file);
 
                   finish();
-                });
+                } else {
+                  preprocess(file, function(err) {
+                    buckets[i].push(file);
+
+                    if (err) {
+                      addError(path);
+                    }
+
+                    finish();
+                  });
+                }
               } else {
                 log.debug('Ignored directory "%s"', path);
                 finish();
diff --git a/lib/middleware/common.js b/lib/middleware/common.js
@@ -28,7 +28,7 @@ var serve404 = function(response, path) {
 var createServeFile = function(fs, directory) {
   var cache = Object.create(null);
 
-  return function(filepath, response, transform, content) {
+  return function(filepath, response, transform, content, doNotCache) {
     var responseData;
 
     if (directory) {
@@ -40,7 +40,7 @@ var createServeFile = function(fs, directory) {
     }
 
     // serve from cache
-    if (content) {
+    if (content && !doNotCache) {
       response.setHeader('Content-Type', mime.lookup(filepath, 'text/plain'));
 
       // call custom transform fn to transform the data
@@ -57,7 +57,9 @@ var createServeFile = function(fs, directory) {
         return serve404(response, filepath);
       }
 
-      cache[filepath] = data.toString();
+      if (!doNotCache) {
+        cache[filepath] = data.toString();
+      }
 
       response.setHeader('Content-Type', mime.lookup(filepath, 'text/plain'));
 
diff --git a/lib/middleware/source_files.js b/lib/middleware/source_files.js
@@ -46,7 +46,7 @@ var createSourceFilesMiddleware = function(filesPromise, serveFile,
             // without timestamps - no cache (debug)
             common.setNoCacheHeaders(response);
           }
-        }, file.content);
+        }, file.content, file.doNotCache);
       } else {
         next();
       }
diff --git a/test/unit/file_list.spec.coffee b/test/unit/file_list.spec.coffee
@@ -241,6 +241,20 @@ describe 'file_list', ->
         expect(pathsFrom files.served).to.deep.equal ['/a.txt']
         done()
 
+    it 'should properly mark files that should not be cached', (done) ->
+      # /a.*       => /a.txt                   [nocache FALSE]
+      # /some/*.js => /some/a.js, /some/b.js   [nocache TRUE]
+      files = [new config.Pattern('/a.*'), new config.Pattern('/some/*.js', true, true, true, true)]
+      list = new m.List files, [], emitter, preprocessMock
+
+      refreshListAndThen (files) ->
+        expect(pathsFrom files.served).to.deep.equal ['/a.txt', '/some/a.js', '/some/b.js']
+        expect(preprocessMock.callCount).to.equal 1
+        expect(files.served[0].doNotCache).to.be.false
+        expect(files.served[1].doNotCache).to.be.true
+        expect(files.served[2].doNotCache).to.be.true
+        done()
+
 
   #============================================================================
   # List.getIncludedFiles()
diff --git a/test/unit/middleware/source_files.spec.coffee b/test/unit/middleware/source_files.spec.coffee
@@ -174,3 +174,19 @@ describe 'middleware.source_files', ->
       done()
 
     callHandlerWith '/absolute/some/file.js'
+
+  it 'should not use cached content if doNotCache is set', (done) ->
+    cachedFile = new File('/src/some.js')
+    cachedFile.content = 'cached-content'
+    cachedFile.doNotCache = true
+
+    servedFiles [
+      cachedFile
+    ]
+
+    response.once 'end', ->
+      expect(nextSpy).not.to.have.been.called
+      expect(response).to.beServedAs 200, 'js-source'
+      done()
+
+    callHandlerWith '/absolute/src/some.js'

Original file line number	Diff line number	Diff line change
`@@ -46,7 +46,7 @@ var createSourceFilesMiddleware = function(filesPromise, serveFile,`
`46`	`46`	`// without timestamps - no cache (debug)`
`47`	`47`	`common.setNoCacheHeaders(response);`
`48`	`48`	`}`
`49`		`- }, file.content);`
	`49`	`+ }, file.content, file.doNotCache);`
`50`	`50`	`} else {`
`51`	`51`	`next();`
`52`	`52`	`}`