Fix usage of allowEmpty when also using include / exclude

index.js

@@ -198,6 +198,8 @@ Funnel.prototype.build = function() {
     }
   }
 
+  let inputPathExists = fs.existsSync(inputPath);
+
   let linkedRoots = false;
   if (this.shouldLinkRoots()) {
     linkedRoots = true;
@@ -216,8 +218,6 @@ Funnel.prototype.build = function() {
      * specifying `this.allowEmpty`.
      */
 
-    let inputPathExists = fs.existsSync(inputPath);
-
     // This is specifically looking for broken symlinks.
     let outputPathExists = fs.existsSync(this.outputPath);
 
@@ -255,8 +255,14 @@ Funnel.prototype.build = function() {
     /*eslint-enable no-lonely-if*/
 
     this._isRebuild = true;
-  } else {
+  } else if (inputPathExists) {
     this.processFilters(inputPath);
+  } else if (!this.allowEmpty) {
+    throw new Error(`You specified a \`"srcDir": ${this.srcDir}\` which does not exist and did not specify \`"allowEmpty": true\`.`);
+  } else { // !inputPathExists && this.allowEmpty
+    // Just make an empty folder so that any downstream consumers who don't know
+    // to ignore this on `allowEmpty` don't get trolled.
+    mkdirp(this.destPath);
   }
 
   this._debug('build, %o', {

tests/index.js

@@ -320,6 +320,51 @@ describe('broccoli-funnel', function() {
 
       expect(node._matchedWalk).to.eql(true);
     });
+
+    it('throws error on unspecified allowEmpty', function() {
+      let assertions = 0;
+      let inputPath = `${FIXTURE_INPUT}/dir1`;
+      let node = new Funnel(inputPath, {
+        include: ['*'],
+        srcDir: 'subdir3',
+        destDir: 'subdir3',
+      });
+
+      builder = new broccoli.Builder(node);
+      return builder.build()
+        .catch(error => {
+          expect(error.message).to.contain('You specified a `"srcDir": subdir3` which does not exist and did not specify `"allowEmpty": true`.');
+          assertions++;
+        })
+        .then(() => {
+          expect(assertions).to.equal(1, 'Build threw an error.');
+        });
+    });
+
+    it('does not error with input node at a missing nested source', function() {
+      let inputPath = `${FIXTURE_INPUT}/dir1`;
+      let node = new Funnel(inputPath, {
+        include: ['*'],
+        srcDir: 'subdir3',
+        allowEmpty: true,
+      });
+
+      let expected = [];
+
+      builder = new broccoli.Builder(node);
+      return builder.build()
+        .then(results => {
+          let outputPath = results.directory;
+
+          expect(walkSync(outputPath)).to.eql(expected);
+        })
+        .then(() => builder.build())
+        .then(results => {
+          let outputPath = results.directory;
+
+          expect(walkSync(outputPath)).to.eql(expected);
+        });
+    });
   });
 
   describe('without filtering options', function() {