istanbul/lib/store/tmp.js

Yet another JS code coverage tool that computes statement, line, function and branch coverage with module loader hooks to transparently add coverage when running tests. Supports all JS coverage use cases including unit tests, server side functional tests

/*
 Copyright (c) 2012, Yahoo! Inc.  All rights reserved.
 Copyrights licensed under the New BSD License. See the accompanying LICENSE file for terms.
 */

var util = require('util'),
    path = require('path'),
    os = require('os'),
    fs = require('fs'),
    mkdirp = require('mkdirp'),
    Store = require('./index');

function makeTempDir() {
    var dir = path.join(os.tmpdir ? os.tmpdir() : /* istanbul ignore next */ (process.env.TMPDIR || '/tmp'), 'ts' + new Date().getTime());
    mkdirp.sync(dir);
    return dir;
}
/**
 * a `Store` implementation using temporary files.
 *
 * Usage
 * -----
 *
 *      var store = require('istanbul').Store.create('tmp');
 *
 *
 * @class TmpStore
 * @extends Store
 * @module store
 * @param {Object} opts Optional.
 * @param {String} [opts.tmp] a pre-existing directory to use as the `tmp` directory. When not specified, a random directory
 *      is created under `os.tmpdir()`
 * @constructor
 */
function TmpStore(opts) {
    opts = opts || {};
    this.tmp = opts.tmp || makeTempDir();
    this.map = {};
    this.seq = 0;
    this.prefix = 't' + new Date().getTime() + '-';
}

TmpStore.TYPE = 'tmp';
util.inherits(TmpStore, Store);

Store.mix(TmpStore, {
    generateTmpFileName: function () {
        this.seq += 1;
        return path.join(this.tmp, this.prefix + this.seq + '.tmp');
    },

    set: function (key, contents) {
        var tmpFile = this.generateTmpFileName();
        fs.writeFileSync(tmpFile, contents, 'utf8');
        this.map[key] = tmpFile;
    },

    get: function (key) {
        var tmpFile = this.map[key];
        if (!tmpFile) { throw new Error('Unable to find tmp entry for [' + tmpFile + ']'); }
        return fs.readFileSync(tmpFile, 'utf8');
    },

    hasKey: function (key) {
        return !!this.map[key];
    },

    keys: function () {
        return Object.keys(this.map);
    },

    dispose: function () {
        var map = this.map;
        Object.keys(map).forEach(function (key) {
            fs.unlinkSync(map[key]);
        });
        this.map = {};
    }
});

module.exports = TmpStore;