Improved error handling.

Author: ezzatron

bin/couchdb-builder

@@ -0,0 +1,2 @@
+#!/usr/bin/env node
+require(__dirname + '/../lib/cli.js')(process, console);

lib/cli.js

@@ -22,6 +22,12 @@
     "url": "http://ezzatron.com/"
   },
   "main": "lib/couchdb-builder.js",
+  "bin": {
+    "couchdb-builder": "bin/couchdb-builder"
+  },
+  "scripts": {
+    "test": "scripts/test"
+  },
   "engines": {
     "node": ">= 0.10.0",
     "npm": ">= 1.0.0"
@@ -36,9 +42,6 @@
     "mocha": "^2.2.5",
     "sinon": "^1.14.1"
   },
-  "scripts": {
-    "test": "scripts/test"
-  },
   "dependencies": {
     "bluebird": "^3.1.5",
     "readdirp": "^2.0.0"

lib/handler/CommonCoffeeHandler.js

@@ -2,4 +2,5 @@
 
 set -e
 
+rm -rf ./lib
 node_modules/.bin/coffee --output lib --compile src

lib/handler/CommonJsHandler.js

@@ -0,0 +1,13 @@
+module.exports = (_process, _console, builder = require '.') ->
+    argv = _process.argv.slice 2
+
+    unless argv.length
+        _console.error 'Path is required.'
+
+        return _process.exit 1
+
+    return builder.build argv[0]
+    .then (result) ->
+        return _console.log JSON.stringify result, null, 2
+    .catch (error) ->
+        return _console.error error.toString()

lib/handler/JsonHandler.js

@@ -4,6 +4,8 @@ path = require 'path'
 Promise = require 'bluebird'
 util = require 'util'
 
+HandlerError = require './error/HandlerError'
+
 module.exports = class CommonCoffeeHandler
 
     constructor: (@template) ->
@@ -20,11 +22,16 @@ module.exports = class CommonCoffeeHandler
         return resolve null if path.extname(filePath) isnt '.coffee'
 
         fs.readFile filePath, (error, data) =>
-            return reject error if error
+            if error
+                error = new HandlerError 'CommonCoffeeHandler', filePath, error
+
+                return reject error
 
             try
                 js = coffee.compile data.toString()
             catch error
+                error = new HandlerError 'CommonCoffeeHandler', filePath, error
+
                 return reject error
 
             resolve [

lib/handler/TextHandler.js

@@ -3,6 +3,8 @@ path = require 'path'
 Promise = require 'bluebird'
 util = require 'util'
 
+HandlerError = require './error/HandlerError'
+
 module.exports = class CommonJsHandler
 
     constructor: (@template) ->
@@ -21,7 +23,10 @@ module.exports = class CommonJsHandler
         return resolve null if path.extname(filePath) isnt '.js'
 
         fs.readFile filePath, (error, data) =>
-            return reject error if error
+            if error
+                error = new HandlerError 'CommonJsHandler', filePath, error
+
+                return reject error
 
             resolve [
                 path.basename filePath, '.js'

lib/handler/error/HandlerError.js

@@ -2,17 +2,24 @@ fs = require 'fs'
 path = require 'path'
 Promise = require 'bluebird'
 
+HandlerError = require './error/HandlerError'
+
 module.exports = class JsonHandler
 
     handleFile: (filePath) -> new Promise (resolve, reject) ->
         return resolve null if path.extname(filePath) isnt '.json'
 
         fs.readFile filePath, (error, json) ->
-            return reject error if error
+            if error
+                error = new HandlerError 'JsonHandler', filePath, error
+
+                return reject error
 
             try
                 data = JSON.parse json
             catch error
+                error = new HandlerError 'JsonHandler', filePath, error
+
                 return reject error
 
             resolve [path.basename(filePath, '.json'), data]

package.json

@@ -2,6 +2,8 @@ fs = require 'fs'
 path = require 'path'
 Promise = require 'bluebird'
 
+HandlerError = require './error/HandlerError'
+
 module.exports = class TextHandler
 
     constructor: (@extensions = ['', '.txt']) ->
@@ -12,7 +14,10 @@ module.exports = class TextHandler
         return resolve null unless extension in @extensions
 
         fs.readFile filePath, (error, data) ->
-            return reject error if error
+            if error
+                error = new HandlerError 'TextHandler', filePath, error
+
+                return reject error
 
             resolve [
                 path.basename filePath, extension

scripts/build

@@ -0,0 +1,10 @@
+module.exports = class HandlerError extends Error
+
+    constructor: (@handlerName, @filename, @cause) ->
+        @message = "#{@handlerName} could not process '#{@filename}'."
+
+    toString: ->
+        string = @message
+        string += " Caused by:\n\n#{@cause.toString()}" if @cause
+
+        return string

src/cli.coffee

@@ -0,0 +1,39 @@
+Promise = require 'bluebird'
+
+cli = require '../../src/cli'
+
+describe 'CLI', ->
+
+    beforeEach ->
+        @process =
+            argv: ['a', 'b', 'c']
+            exit: sinon.spy()
+        @console = sinon.spyObject 'console', ['log', 'error']
+        @builder = sinon.spyObject 'builder', ['build']
+
+    it 'outputs indented JSON', ->
+        expected = '''
+            {
+              "a": 1,
+              "b": 2
+            }
+        '''
+        @builder.build.returns Promise.resolve a: 1, b: 2
+
+        return cli @process, @console, @builder
+        .then =>
+            sinon.assert.calledWith @builder.build, 'c'
+            sinon.assert.calledWith @console.log, expected
+
+    it 'outputs error messages on failure', ->
+        @builder.build.returns Promise.reject 'Error message.'
+
+        return cli @process, @console, @builder
+        .then =>
+            sinon.assert.calledWith @console.error, 'Error message.'
+
+    it 'requires a path argument', ->
+        @process.argv = ['a', 'b']
+        cli @process, @console, @builder
+
+        sinon.assert.calledWith @console.error, 'Path is required.'

src/handler/CommonCoffeeHandler.coffee

@@ -1,4 +1,5 @@
 CommonCoffeeHandler = require '../../../src/handler/CommonCoffeeHandler'
+HandlerError = require '../../../src/handler/error/HandlerError'
 
 describe 'CommonCoffeeHandler', ->
 
@@ -45,11 +46,11 @@ describe 'CommonCoffeeHandler', ->
 
         return @subject.handleFile path
         .catch (actual) ->
-            assert.instanceOf actual, SyntaxError
+            assert.instanceOf actual, HandlerError
 
     it 'handles file system errors', ->
         path = "#{__dirname}/../../fixture/invalid/nonexistent.coffee"
 
         return @subject.handleFile path
         .catch (actual) ->
-            assert.instanceOf actual, Error
+            assert.instanceOf actual, HandlerError

src/handler/CommonJsHandler.coffee

@@ -1,4 +1,5 @@
 CommonJsHandler = require '../../../src/handler/CommonJsHandler'
+HandlerError = require '../../../src/handler/error/HandlerError'
 
 describe 'CommonJsHandler', ->
 
@@ -39,4 +40,4 @@ describe 'CommonJsHandler', ->
 
         return @subject.handleFile path
         .catch (actual) ->
-            assert.instanceOf actual, Error
+            assert.instanceOf actual, HandlerError