Improve CommonJS modules

Compiling a template as a CommonJS module returns a function that must be hydrated with a Dust:

    var tmpl = require('./my/tmpl.js')(dust);

Once you have a handle on that object, you can either invoke it directly:

    tmpl(context, function(err, out) { ... })
    tmpl(context).on('data', ...)

Or you can pass it to `dust.render`:

    dust.render(tmpl, ...)

Or you can access the compiled template if you need to do something with it:

    tmpl.template; // function body_0(chunk, context, bodies, params) { ... }

Gruntfile.js

@@ -181,6 +181,17 @@ module.exports = function(grunt) {
       }
     },
     jasmine_nodejs: {
+      cjs: {
+        specs: ['test/jasmine-test/spec/cjsSpec.js'],
+        options: {
+          reporters: {
+            console: {
+              colors: false,
+              verbose: false
+            }
+          }
+        }
+      },
       dustc: {
         specs: ['test/jasmine-test/spec/cli/*'],
         options: {
@@ -286,11 +297,11 @@ module.exports = function(grunt) {
   grunt.registerTask('build',          ['clean:build', 'shell:buildParser', 'buildLib', 'uglify']);
 
   //test tasks
-  grunt.registerTask('testNode',       ['shell:oldTests']);
+  grunt.registerTask('testNode',       ['jasmine_nodejs:cjs', 'shell:oldTests']);
   grunt.registerTask('testRhino',      ['build', 'shell:testRhino']);
   grunt.registerTask('testPhantom',    ['build', 'jasmine:testProd']);
   grunt.registerTask('testCli',        ['build', 'jasmine_nodejs:dustc']);
-  grunt.registerTask('test',           ['build', 'jasmine:testProd', 'jasmine_nodejs:dustc', 'shell:oldTests', 'shell:testRhino', 'jasmine:coverage']);
+  grunt.registerTask('test',           ['build', 'jasmine:testProd', 'jasmine_nodejs:dustc', 'jasmine_nodejs:cjs', 'shell:oldTests', 'shell:testRhino', 'jasmine:coverage']);
 
   //task for debugging in browser
   grunt.registerTask('dev',            ['build', 'jasmine:testDev:build', 'connect:testServer','log:testClient', 'watch:lib']);

lib/compiler.js

@@ -163,7 +163,8 @@
     escapedName = dust.escapeJs(name),
     AMDName = name? '"' + escapedName + '",' : '',
     compiled = 'function(dust){',
-    entry = compiler.compileNode(context, ast);
+    entry = compiler.compileNode(context, ast),
+    iife;
 
     if(name) {
       compiled += 'dust.register("' + escapedName + '",' + entry + ');';
@@ -173,12 +174,17 @@
                 compileBodies(context) +
                 'return ' + entry + '}';
 
+    iife = '(' + compiled + '(dust));';
+
     if(dust.config.amd) {
       return 'define(' + AMDName + '["dust.core"],' + compiled + ');';
     } else if(dust.config.cjs) {
-      return 'module.exports=' + compiled;
+      return 'module.exports=function(dust){' +
+             'var tmpl=' + iife +
+             'var f=' + loaderFor().toString() + ';' +
+             'f.template=tmpl;return f}';
     } else {
-      return '(' + compiled + '(dust));';
+      return iife;
     }
   }
 
@@ -432,21 +438,18 @@
 
   function renderSource(source, context, callback) {
     var tmpl = dust.loadSource(dust.compile(source));
-    if(callback) {
-      return dust.render(tmpl, context, callback);
-    } else {
-      return dust.stream(tmpl, context);
-    }
+    return loaderFor(tmpl)(context, callback);
   }
 
   function compileFn(source, name) {
     var tmpl = dust.loadSource(dust.compile(source, name));
-    return function(context, callback) {
-      if(callback) {
-        return dust.render(tmpl, context, callback);
-      } else {
-        return dust.stream(tmpl, context);
-      }
+    return loaderFor(tmpl);
+  }
+
+  function loaderFor(tmpl) {
+    return function load(ctx, cb) {
+      var fn = cb ? 'render' : 'stream';
+      return dust[fn](tmpl, ctx, cb);
     };
   }
 

lib/dust.js

@@ -121,7 +121,18 @@
       dust.cache = {};
     }
 
-    var tmpl = dust.isTemplateFn(nameOrTemplate) ? nameOrTemplate : dust.cache[nameOrTemplate];
+    var tmpl;
+    if(typeof nameOrTemplate === 'function' && nameOrTemplate.template) {
+      // Sugar away CommonJS module templates
+      tmpl = nameOrTemplate.template;
+    } else if(dust.isTemplateFn(nameOrTemplate)) {
+      // Template functions passed directly
+      tmpl = nameOrTemplate;
+    } else {
+      // Load a template with this name from cache
+      tmpl = dust.cache[nameOrTemplate];
+    }
+
     if (tmpl) {
       return tmpl(chunk, Context.wrap(context, tmpl.templateName));
     } else {

test/jasmine-test/spec/cjsSpec.js

@@ -0,0 +1,59 @@
+/*global describe,expect,it,beforeEach */
+/*jshint evil:true*/
+var dust = require('../../../');
+
+function load(tmpl) {
+  dust.config.cjs = true;
+  return eval(dust.compile(tmpl, 'hello'))(dust);
+}
+
+describe('CommonJS template', function() {
+  var template = "Hello {world}!",
+      context = { world: "world" },
+      rendered = "Hello world!",
+      templateName = 'hello',
+      tmpl;
+
+  beforeEach(function() {
+    tmpl = load(template);
+  });
+
+  it('can be invoked to render', function() {
+    tmpl(context, function(err, out) {
+      expect(out).toEqual(rendered);
+    });
+  });
+
+  it('can be invoked to stream', function(done) {
+    tmpl(context).on('data', function(out) {
+      expect(out).toEqual(rendered);
+      done();
+    });
+  });
+
+  it('can be passed to dust.render', function() {
+    dust.render(tmpl, context, function(err, out) {
+      expect(out).toEqual(rendered);
+    });
+  });
+
+  it('can be passed to dust.stream', function(done) {
+    dust.stream(tmpl, context).on('data', function(out) {
+      expect(out).toEqual(rendered);
+      done();
+    });
+  });
+
+  it('has a template property that can be passed to dust.render', function() {
+    expect(tmpl.template.templateName).toEqual(templateName);
+    dust.render(tmpl.template, context, function(err, out) {
+      expect(out).toEqual(rendered);
+    });
+  });
+
+  it('has a name that can be passed to dust.render', function() {
+    dust.render(templateName, context, function(err, out) {
+      expect(out).toEqual(rendered);
+    });
+  });
+});

test/jasmine-test/spec/cli/cliSpec.js

@@ -1,3 +1,4 @@
+/*global describe,expect,it,afterEach */
 var path = require('path'),
     fs = require('fs'),
     exec = require('child_process').exec;