1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304 | 1
1
1
1
1
1
1
12
12
12
12
12
12
12
1
3
2
2
1
1
1
2
2
1
7
7
1
1
1
1
2
2
1
3
3
1
2
2
2
1
10
10
10
10
10
17
10
1
2
2
2
2
1
1
1
1
1
12
12
12
11
11
11
1
1
2
2
2
2
4
2
2
2
2
4
2
1
5
1
2
2
2
1
1
1
2
1
1
1
2
2
2
1
1
1
1
1
4
4
4
4
3
1
1
1
1
5
5
5
19
19
159
83
19
19
9
9
5
5
5
5
19
5
1
9
9
9
9
24
24
9
1
11
11
1
1
21
21
42
42
21
1
| var path = require('path');
var fs = require('fs');
var util = require('util');
var yaml = require('js-yaml');
var async = require('async');
var util = require('util');
var Loader = function() {
this.load = this.load.bind(this);
this.parseYaml = this.parseYaml.bind(this);
this.add = this.add.bind(this);
this.context = {};
this.loads = [];
this.loads = [];
this.loads = [];
};
/**
* Flexible loader function that can load files from objects or directories.
*/
Loader.prototype.add = function(item, options) {
switch (typeof item) {
case 'string':
this.addFileOrDirectory(item);
break;
case 'object':
this.addObject(item);
break;
}
};
Loader.prototype.addFileOrDirectory = function(path) {
this.loads.push(this.loadFileOrDirectory.bind(this, path));
return this;
};
/**
* Register a single yaml configuration path to be merged into the configuration.
*
* @param filePath
* The path on disk to register.
*/
Loader.prototype.addFile = function(filePath) {
this.loads.push(this.loadFile.bind(this, filePath));
return this;
};
/**
* Register a directory that will have config files loaded where files loaded
* earlier will be overridden by those loaded later.
*/
Loader.prototype.addDirectory = function(directoryPath) {
this.loads.push(this.loadDirectory.bind(this, directoryPath));
return this;
};
/**
* Register a directory that will have config files loaded into an array.
*/
Loader.prototype.addDirectoryArray = function(directoryPath, configKey) {
this.loads.push(this.loadDirectoryArray.bind(this, directoryPath, configKey));
return this;
};
Loader.prototype.addObject = function(object, translator) {
this.loads.push(this.loadObject.bind(this, object, this.context));
return this;
};
Loader.prototype.addAndNormalizeObject = function(object, format) {
format = format || 'camelCase';
this.loads.push(this.loadObject.bind(this, this.translateKeyFormat(object, format), this.context));
return this;
};
/**
* Construct a configuration object from the registered paths.
*/
Loader.prototype.load = function(done) {
var self = this;
self.context.config = {};
async.series(this.loads, function(error, configs) {
var config = {};
for (i in configs) {
config = self.mergeConifguration(config, configs[i]);
}
done(error, config);
});
};
/**
* Load either a file or a directory based on path.
*/
Loader.prototype.loadFileOrDirectory = function(path, done) {
var self = this;
fs.stat(path, function(error, stat) {
Iif (error) return done(error);
if (stat.isDirectory()) {
self.loadDirectory(path, function(error, config) {
done(error, config);
});
}
else {
self.loadFile(path, function(error, config) {
done(error, config);
});
}
});
};
/**
* Load configuration for an individual file.
*/
Loader.prototype.loadFile = function(path, done) {
var self = this;
fs.exists(path, function(exists) {
if (exists) {
fs.readFile(path, 'utf8', function(error, data) {
/* istanbul ignore if: This error condition is near impossible to test. */
Iif (error) return done(error);
self.parseYaml(data, done);
});
}
else {
done(new Error(util.format('Specified configuration file `%s` not found.', path)));
}
});
};
/**
* Load config files from a directory allowing new entries to override old.
*/
Loader.prototype.loadDirectory = function(dirPath, done) {
var self = this;
fs.readdir(dirPath, function(error, files) {
/* istanbul ignore if: This error condition is near impossible to test. */
Iif (error) return done(error);
var loadFile = function(filePath, cb) {
self.loadFile(path.join(dirPath, filePath), cb);
};
async.map(files, loadFile, function(error, confs) {
/* istanbul ignore if: This error condition is near impossible to test. */
Iif (error) return done(error);
var conf = {};
for (i in confs) {
conf = self.mergeConifguration(conf, confs[i]);
}
done(null, conf);
});
});
};
Loader.prototype.loadObject = function(object, context, done) {
return done(null, object);
};
/**
* Load config files from a directory into an array.
*/
Loader.prototype.loadDirectoryArray = function(dirPath, configKey, done) {
var self = this;
fs.readdir(dirPath, function(error, files) {
/* istanbul ignore if: This error condition is near impossible to test. */
if (error) return done(error);
var output = {};
output[configKey] = [];
var fileLoadHandler = function(file, cb){
fs.readFile(path.join(dirPath, file), 'utf8', cb);
};
async.map(files, fileLoadHandler, function(error, confs) {
/* istanbul ignore if: This error condition is near impossible to test. */
Iif (error) return done(error);
for (i in confs) {
try {
var conf = yaml.safeLoad(confs[i]);
output[configKey].push(conf);
}
catch(e) {
// Do something?
}
}
done(null, output);
});
});
};
/**
* Translate configuration from an object then perform a transformation on its
* keys.
*
* This method is useful for loading environment variables in the form of
* `SOME_NAME` and using them to override camel case variables like `someName`.
*
* @param object
* The object whose keys should be transformed.
* @param keys
* An array of keys to load from the object.
*/
Loader.prototype.translateKeys = function(object, keys, done) {
var output = {};
keys = keys || Object.keys(object);
for (i in keys) {
var key = keys[i];
// Covert camel case into environment variables (into all upper with
// underscores).
var replacer = function(match) { return '_' + match};
var translatedName = key.replace(/[A-Z]/g, replacer).toUpperCase();
if (object.hasOwnProperty(translatedName)) {
output[key] = object[translatedName];
}
}
Eif (done) {
setImmediate(done.bind(null, null, output));
}
return output;
};
/**
* Format the keys on an object converting to them to a supported format.
*
* @param object
* A plain old javascript object.
* @param format
* A supported format to convert the keys to.
*
* These are also the supported from formats.
* 'camelCase' - standard camelCase with capitalization splitting parts.
* 'CAPITAL_UNDERSCORES' - standard ENV variable format
* 'lower-dashes' - all lower case with dashes, typical of cli parameters.
*/
Loader.prototype.translateKeyFormat = function(object, format) {
var output = {};
format = format || 'camelCase';
for (key in object) {
Eif (object.hasOwnProperty(key)) {
var parts = key
.split(/([A-Z][a-z]+)|_|-/g)
.filter(function(element) {
return element;
})
.map(function(item) {
return item.toLowerCase();
});
var newKey = '';
switch (format) {
default:
case 'camelCase':
newKey = this.formatCamelCase(parts);
break;
case 'CAPITAL_UNDERSCORES':
newKey = parts.join('_').toUpperCase();
break;
case 'lower-dashes':
newKey = parts.join('-').toLowerCase();
break;
}
output[newKey] = object[key];
}
}
return output;
};
/**
* Utility function to format an array of word parts in camelCase.
*/
Loader.prototype.formatCamelCase = function(parts) {
var parts = parts.slice();
var output = parts.shift();
var part = '';
for (i in parts) {
part = parts[i];
output += part.substr(0, 1).toUpperCase() + part.substring(1);
}
return output;
}
/**
* Parse a yaml file and report an error if necessary.
*/
Loader.prototype.parseYaml = function(data, done) {
try {
return done(null, yaml.safeLoad(data));
}
catch (error) {
setImmediate(done.bind(null, error));
}
}
/**
* Merge two confiugration objects overriding values on the first with values on
* the second.
*/
Loader.prototype.mergeConifguration = function(one, two) {
var i = null;
for (i in two) {
Eif (two.hasOwnProperty(i)) {
one[i] = two[i];
}
}
return one;
};
module.exports = Loader;
|