Add needsCache capability.

docs/node-api.md

@@ -108,21 +108,21 @@ hypothetical "broccoli-fooscript" plugin would communicate with Broccoli:
                             |                        |
                             |   broccoli-fooscript   |
                        +----+                        |
-                       |    +-----------+------------+
+                       |    +-----------|------------+
                        |                |
 npm dependency:        |                | broccoli-plugin base class interface (easy to
 broccoli-plugin ^1.2.3 |                | use), described in the broccoli-plugin README
                        |                |
-                       |    +-----------+------------+
+                       |    +-----------|------------+
                        +---->                        |
                             | broccoli-plugin 1.2.3  |
                             |                        |
-                            +-----------+------------+
+                            +-----------|------------+
                                         |
 (no npm dependency here)                | Broccoli node API (versioned, complex),
                                         | described in this document
                                         |
-                            +-----------+------------+
+                            +-----------|------------+
                             |                        |
                             |   broccoli (Builder)   |
                             |                        |
@@ -242,6 +242,9 @@ following `nodeInfo` properties are specific to "transform" nodes:
       Broccoli process terminates (for example, when the Broccoli server is
       restarted).
 
+      If a `cachePath` is not needed/desired, a plugin can opt-out of its creation
+      via the `needsCache` flag metioned below.
+
 * `nodeInfo.getCallbackObject` {`function()`, returns an object}:
   The Builder will call this function once after it has called `setup`. This
   function will not be called more than once throughout the lifetime of the
@@ -271,6 +274,9 @@ following `nodeInfo` properties are specific to "transform" nodes:
   between Broccoli server restarts or `broccoli build` invocations even if
   `persistentOutput` is true.
 
+* `nodeInfo.needsCache` {boolean}:
+  If `false`, a cache directory will not be created. If `true`, a cache directory
+  will be created and its path will be available as `this.cachePath`.
 
 #### Source nodes
 

lib/builder.js

@@ -257,7 +257,10 @@ Builder.prototype.setupTmpDirs = function() {
         return nw.outputPath
       })
       nodeWrapper.outputPath = this.mkTmpDir(nodeWrapper, 'out')
-      nodeWrapper.cachePath = this.mkTmpDir(nodeWrapper, 'cache')
+
+      if (nodeWrapper.nodeInfo.needsCache) {
+        nodeWrapper.cachePath = this.mkTmpDir(nodeWrapper, 'cache')
+      }
     } else { // nodeType === 'source'
       // We could name this .sourcePath, but with .outputPath the code is simpler.
       nodeWrapper.outputPath = nodeWrapper.nodeInfo.sourceDirectory
@@ -502,7 +505,8 @@ TransformNodeWrapper.prototype.nodeInfoToJSON = function() {
     nodeType: 'transform',
     name: this.nodeInfo.name,
     annotation: this.nodeInfo.annotation,
-    persistentOutput: this.nodeInfo.persistentOutput
+    persistentOutput: this.nodeInfo.persistentOutput,
+    needsCache: this.nodeInfo.needsCache
     // leave out instantiationStack (too long), inputNodes, and callbacks
   })
 }

package.json

@@ -19,7 +19,7 @@
   },
   "homepage": "https://github.com/broccolijs/broccoli",
   "dependencies": {
-    "broccoli-node-info": "1.0.0",
+    "broccoli-node-info": "1.1.0",
     "broccoli-slow-trees": "^2.0.0",
     "broccoli-source": "^1.1.0",
     "commander": "^2.5.0",
@@ -42,6 +42,7 @@
     "mocha": "^3.0.0",
     "mocha-jshint": "^2.2.5",
     "multidep": "^2.0.0",
+    "semver": "^5.3.0",
     "sinon": "^1.17.1",
     "sinon-chai": "^2.8.0",
     "symlink-or-copy": "^1.0.1"

test/builder_test.js

@@ -14,8 +14,9 @@ var chai = require('chai'), expect = chai.expect
 var chaiAsPromised = require('chai-as-promised'); chai.use(chaiAsPromised)
 var sinonChai = require('sinon-chai'); chai.use(sinonChai)
 var multidepRequire = require('multidep')('test/multidep.json')
+var semver = require('semver')
 
-var Plugin = multidepRequire('broccoli-plugin', '1.2.2')
+var Plugin = multidepRequire('broccoli-plugin', '1.3.0')
 var broccoliSource = multidepRequire('broccoli-source', '1.1.0')
 
 // Clean up left-over temporary directories on uncaught exception.
@@ -117,7 +118,7 @@ describe('Builder', function() {
           })
         })
 
-        it('supplies a cachePath', function() {
+        it('supplies a cachePath by default', function() {
           // inputPath and outputPath are tested implicitly by the other tests,
           // but cachePath isn't, so we have this test case
 
@@ -133,7 +134,47 @@ describe('Builder', function() {
           builder = new Builder(new CacheTestPlugin)
           return builder.build()
         })
+
+        it('supplies a cachePath when requested', function() {
+          // inputPath and outputPath are tested implicitly by the other tests,
+          // but cachePath isn't, so we have this test case
+
+          CacheTestPlugin.prototype = Object.create(Plugin.prototype)
+          CacheTestPlugin.prototype.constructor = CacheTestPlugin
+          function CacheTestPlugin() {
+            Plugin.call(this, [], {
+              needsCache: true
+            })
+          }
+          CacheTestPlugin.prototype.build = function() {
+            expect(fs.existsSync(this.cachePath)).to.be.true
+          }
+
+          builder = new Builder(new CacheTestPlugin)
+          return builder.build()
+        })
       })
+
+      if (version === 'master' || semver.gt(version, '1.3.0')) {
+        it('does not create a cachePath when opt-ed out', function() {
+          // inputPath and outputPath are tested implicitly by the other tests,
+          // but cachePath isn't, so we have this test case
+
+          CacheTestPlugin.prototype = Object.create(Plugin.prototype)
+          CacheTestPlugin.prototype.constructor = CacheTestPlugin
+          function CacheTestPlugin() {
+            Plugin.call(this, [], {
+              needsCache: false
+            })
+          }
+          CacheTestPlugin.prototype.build = function() {
+            expect(this.cachePath).to.equal(undefined)
+          }
+
+          builder = new Builder(new CacheTestPlugin)
+          return builder.build()
+        })
+      }
     })
 
     describe('persistentOutput flag', function() {
@@ -557,7 +598,8 @@ describe('Builder', function() {
             nodeType: 'transform',
             name: 'MergePlugin',
             annotation: null,
-            persistentOutput: false
+            persistentOutput: false,
+            needsCache: true
           },
           buildState: {
             selfTime: 1,

test/multidep.json

@@ -1,7 +1,7 @@
 {
   "path": "test/multidep",
   "versions": {
-    "broccoli-plugin": ["1.0.0", "1.1.0", "1.2.2"],
+    "broccoli-plugin": ["1.0.0", "1.1.0", "1.2.3", "1.3.0"],
     "broccoli-source": ["1.1.0"]
   }
 }