-1
我想寫一個更新的手錶模塊，使用fs.watch方法，而不是watchFile方法。摩卡測試失敗，但實施工程
到目前爲止，它的工作很好，但只有當我在摩卡之外運行它。我無法弄清楚爲什麼我的單元測試會發脾氣，也許這裏有人可以？
這裏是我的類代碼：
/**
* requirements
*/
var fs, path, events;
fs = require('fs');
path = require('path');
events = require('events');
/**
* private
*/
var Monitor = function(directory, options) {
this.directory = directory;
this.options = options || {};
(this.options.lazy && this.empty()) || this.walk(this.directory);
this.watch(this.directory);
};
Monitor.prototype = new events.EventEmitter();
Monitor.prototype.watch = function(directory, stats) {
var stats = stats || {};
if (!this.directories[directory]) {
var w = fs.watch(directory, this.options, this.justlookatit.bind(this));
}
this.directories[directory] = { 'stats': stats, 'w': w };
};
Monitor.prototype.directories = function() {
if (!Object.keys(this.directories).length) {
this.walk(this.directory);
}
return this.directories;
};
Monitor.prototype.files = function() {
if (!Object.keys(this.files).length) {
this.walk(this.directory);
}
return this.files;
};
Monitor.prototype.unwatch = function() {
if (!Object.keys(this.directories).length) {
for (var dir in this.directories) {
dir.w.close();
}
}
};
Monitor.prototype.empty = function() {
this.unwatch();
this.files = {};
this.directories = {};
};
Monitor.prototype.walk = function(directory) {
var monitor = this;
this.empty();
fs.readdir(directory, function(err, files) {
if (err) return;
for (var file in files) {
var fullname = path.resolve(files[file]);
if (!monitor.options.filter || monitor.options.filter(fullname)) {
fs.stat(fullname, function(err, stats) {
if (err) return;
if (stats.isDirectory()) {
monitor.walk(fullname);
monitor.watch(fullname, stats);
} else {
monitor.files[fullname] = stats;
}
});
}
}
});
};
Monitor.prototype.justlookatit = function(action, file) {
var monitor = this;
var fullname = path.resolve(file);
if (this.options.filter && !this.options.filer(fullname)) return;
fs.exists(fullname, function(exists) {
if (exists) {
fs.stat(fullname, function(err, stats) {
if (stats.isDirectory()) {
monitor.watch(fullname, stats);
} else {
if (monitor.files[fullname]) {
if (stats.mtime.getTime() > monitor.files[fullname].mtime.getTime()) {
monitor.emit('modified', fullname, stats);
}
} else {
monitor.emit('added', fullname, stats);
}
monitor.files[fullname] = stats;
}
});
} else {
if (monitor.files[fullname]) {
delete monitor.files[fullname];
monitor.emit('deleted', fullname);
} else if (monitor.directories[fullname]) {
monitor.directories[fullname].w.close();
delete monitor.directories[fullname];
}
}
});
};
/**
* exports
*/
exports.start = function(directory, options) {
return new Monitor(directory, options);
};
這是我的工作外部測試代碼：
var watch = require("./watch.js");
var fs = require('fs');
monitor = watch.start(__dirname);
monitor.on('added', function(file, stats) {
console.log("Caught Added: " + file);
});
monitor.on('modified', function(file, stats) {
console.log("Caught Modified: " + file);
});
monitor.on('deleted', function(file) {
console.log("Caught deleted: " + file);
});
// try creating a file immediately
fs.openSync('v.md', 'w');
第一個測試文件運行完全正常，我都試過openSync和open。最後，這裏是一個版本相同的測試代碼，包裹在摩卡單元測試，已超時：
/**
* requirements
*/
var watch, Q, fs, path, mocha, chai, assert;
watch = require('../lib/watch.js');
Q = require('q');
fs = require('fs');
path = require('path');
mocha = require('mocha');
chai = require('chai');
assert = chai.assert;
/**
* variables
*/
var watch_directory = path.join(__dirname, './watch');
/**
* tests
*/
describe('test watch', function() {
it('should create a monitor and run callbacks after fs changes', function(done) {
// I had planned to implement promises that chained the three callbacks
// but couldn't get one of them working in general
var added = function(file, stats) {
console.log("added");
done();
};
var modified = function(file, stats) {
console.log("modified");
};
var deleted = function(file, stats) {
console.log("deleted");
};
// create our service
var monitor = watch.start(watch_directory);
// assert it is defined
assert.isDefined(monitor);
// establish a listener
monitor.on('added', added);
monitor.on('modified', modified);
monitor.on('deleted', deleted);
// here is a file name using the current date to prevent duplication during tests
var file = path.join(watch_directory, (new Date()).getTime() + '.md');
// let's create the file, then delete it
fs.open(file, 'w+', function(err, fileDescriptor) {
// this prints before console output from the watch.js's `justlookatit` method
console.log(err);
console.log("writing to file");
// we probably don't want to try closing the fileDescriptor if the open failed
if (err) return;
// close the file descriptor
fs.close(fileDescriptor, function() {
// delete the file we just created
// fs.unlink(file, function() { /* not a big deal */ });
});
});
// modify a known-existing test file
fs.open('test.md', 'w+', function() {/* we don't care about this */});
})
});
我console.log(fullname)檢查了手表的代碼justlookatit方法裏面，它吐出來的是正確的文件名稱，與單元測試生成的名稱匹配。
然而，當我運行fs.exists時，它接着返回false。由於我不理解它，這意味着文件系統在文件存在之前通知我文件存在，這實際上沒有意義。所以我試圖通過將我的fs.exists方法包裝在setTimeout中來增加額外的延遲，但這並沒有改變結果。我也嘗試過使用openSync和existsSync，並沒有什麼區別。
我很難過，有沒有人有任何想法爲什麼摩卡代碼不工作？
done正在從'added'回調中被調用，當監視器發出添加了一個新文件時，它應該由監視器執行，這是'fs.open'進程打算處理的內容。理想情況下，我會創建一個承諾鏈，一旦三者全部滿足，就會導致完成方法。 – CDeLorme