Add CliError

lib/cli.js

@@ -7,6 +7,7 @@ const fs = require('fs');
 const WatchDetector = require('watch-detector');
 const path = require('path');
 
+const CliError = require('./errors/cli');
 const broccoli = require('./index');
 const messages = require('./messages');
 
@@ -40,8 +41,10 @@ module.exports = function broccoliCLI(args) {
         try {
           guardOutputDir(outputDir, options.overwrite);
         } catch (e) {
-          console.error(e.message);
-          return process.exit(1);
+          if (e instanceof CliError) {
+            console.error(e.message);
+            return process.exit(1);
+          }
         }
         const outputTree = new TreeSync(builder.outputPath, outputDir);
 
@@ -81,8 +84,10 @@ module.exports = function broccoliCLI(args) {
       try {
         guardOutputDir(outputDir, options.overwrite);
       } catch (e) {
-        console.error(e.message);
-        return process.exit(1);
+        if (e instanceof CliError) {
+          console.error(e.message);
+          return process.exit(1);
+        }
       }
 
       const builder = getBuilder(options);
@@ -171,13 +176,13 @@ function guardOutputDir(outputDir, overwrite) {
   if (fs.existsSync(outputDir)) {
     if (overwrite) {
       if (isParentDirectory(outputDir)) {
-        throw new Error(
+        throw new CliError(
           'option --overwrite can not be used if outputPath is a parent directory: ' + outputDir
         );
       }
       return;
     }
-    throw new Error(
+    throw new CliError(
       outputDir +
         '/ already exists; we cannot build into an existing directory, ' +
         'pass --overwrite to overwrite the output directory'

lib/errors/cli.js

@@ -0,0 +1,4 @@
+'use strict';
+
+// Base class for cli errors
+module.exports = class CliError extends Error {};