istanbul/lib/config.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) 2013, Yahoo! Inc.  All rights reserved.
 Copyrights licensed under the New BSD License. See the accompanying LICENSE file for terms.
 */
var path = require('path'),
    fs = require('fs'),
    existsSync = fs.existsSync || path.existsSync,
    CAMEL_PATTERN = /([a-z])([A-Z])/g,
    YML_PATTERN = /\.ya?ml$/,
    yaml = require('js-yaml'),
    defaults = require('./report/common/defaults');

function defaultConfig(includeBackCompatAttrs) {
    var ret = {
        verbose: false,
        instrumentation: {
            root: '.',
            'default-excludes': true,
            excludes: [],
            'embed-source': false,
            variable: '__coverage__',
            compact: true,
            'preserve-comments': false,
            'complete-copy': false,
            'save-baseline': false,
            'baseline-file': './coverage/coverage-baseline.json',
            'include-all-sources': false,
            'include-pid': false
        },
        reporting: {
            print: 'summary',
            reports: [ 'lcov' ],
            dir: './coverage'
        },
        hooks: {
            'hook-run-in-context': false,
            'post-require-hook': null,
            'handle-sigint': false
        },
        check: {
            global: {
                statements: 0,
                lines: 0,
                branches: 0,
                functions: 0,
                excludes: [] // Currently list of files (root + path). For future, extend to patterns.
            },
            each: {
                statements: 0,
                lines: 0,
                branches: 0,
                functions: 0,
                excludes: []
            }
        }
    };
    ret.reporting.watermarks = defaults.watermarks();
    ret.reporting['report-config'] = defaults.defaultReportConfig();

    if (includeBackCompatAttrs) {
        ret.instrumentation['preload-sources'] = false;
    }

    return ret;
}

function dasherize(word) {
    return word.replace(CAMEL_PATTERN, function (match, lch, uch) {
        return lch + '-' + uch.toLowerCase();
    });
}
function isScalar(v) {
    if (v === null) { return true; }
    return v !== undefined && !Array.isArray(v) && typeof v !== 'object';
}

function isObject(v) {
    return typeof v === 'object' && v !== null && !Array.isArray(v);
}

function mergeObjects(explicit, template) {

    var ret = {};

    Object.keys(template).forEach(function (k) {
        var v1 = template[k],
            v2 = explicit[k];

        if (Array.isArray(v1)) {
            ret[k] = Array.isArray(v2) && v2.length > 0 ? v2 : v1;
        } else if (isObject(v1)) {
            v2 = isObject(v2) ? v2 : {};
            ret[k] = mergeObjects(v2, v1);
        } else {
            ret[k] = isScalar(v2) ? v2 : v1;
        }
    });
    return ret;
}

function mergeDefaults(explicit, implicit) {
    return mergeObjects(explicit || {}, implicit);
}

function addMethods() {
    var args = Array.prototype.slice.call(arguments),
        cons = args.shift();

    args.forEach(function (arg) {
        var method = arg,
            property = dasherize(arg);
        cons.prototype[method] = function () {
            return this.config[property];
        };
    });
}

/**
 * Object that returns instrumentation options
 * @class InstrumentOptions
 * @module config
 * @constructor
 * @param config the instrumentation part of the config object
 */
function InstrumentOptions(config) {
    if (config['preload-sources']) {
        console.error('The preload-sources option is deprecated, please use include-all-sources instead.');
        config['include-all-sources'] = config['preload-sources'];
    }
    this.config = config;
}

/**
 * returns if default excludes should be turned on. Used by the `cover` command.
 * @method defaultExcludes
 * @return {Boolean} true if default excludes should be turned on
 */
/**
 * returns if non-JS files should be copied during instrumentation. Used by the
 * `instrument` command.
 * @method completeCopy
 * @return {Boolean} true if non-JS files should be copied
 */
/**
 * returns if the source should be embedded in the instrumented code. Used by the
 * `instrument` command.
 * @method embedSource
 * @return {Boolean} true if the source should be embedded in the instrumented code
 */
/**
 * the coverage variable name to use. Used by the `instrument` command.
 * @method variable
 * @return {String} the coverage variable name to use
 */
/**
 * returns if the output should be compact JS. Used by the `instrument` command.
 * @method compact
 * @return {Boolean} true if the output should be compact
 */
/**
 * returns if comments should be preserved in the generated JS. Used by the
 * `cover` and `instrument` commands.
 * @method preserveComments
 * @return {Boolean} true if comments should be preserved in the generated JS
 */
/**
 * returns if a zero-coverage baseline file should be written as part of
 * instrumentation. This allows reporting to display numbers for files that have
 * no tests. Used by the  `instrument` command.
 * @method saveBaseline
 * @return {Boolean} true if a baseline coverage file should be written.
 */
/**
 * Sets the baseline coverage filename. Used by the  `instrument` command.
 * @method baselineFile
 * @return {String} the name of the baseline coverage file.
 */
/**
 * returns if the coverage filename should include the PID. Used by the  `instrument` command.
 * @method includePid
 * @return {Boolean} true to include pid in coverage filename.
 */


addMethods(InstrumentOptions,
    'defaultExcludes', 'completeCopy',
    'embedSource', 'variable', 'compact', 'preserveComments',
    'saveBaseline', 'baselineFile',
    'includeAllSources', 'includePid');

/**
 * returns the root directory used by istanbul which is typically the root of the
 * source tree. Used by the `cover` and `report` commands.
 * @method root
 * @return {String} the root directory used by istanbul.
 */
InstrumentOptions.prototype.root = function () { return path.resolve(this.config.root); };
/**
 * returns an array of fileset patterns that should be excluded for instrumentation.
 * Used by the `instrument` and `cover` commands.
 * @method excludes
 * @return {Array} an array of fileset patterns that should be excluded for
 *  instrumentation.
 */
InstrumentOptions.prototype.excludes = function (excludeTests) {
    var defs;
    if (this.defaultExcludes()) {
        defs = [ '**/node_modules/**' ];
        if (excludeTests) {
            defs = defs.concat(['**/test/**', '**/tests/**']);
        }
        return defs.concat(this.config.excludes);
    }
    return this.config.excludes;
};

/**
 * Object that returns reporting options
 * @class ReportingOptions
 * @module config
 * @constructor
 * @param config the reporting part of the config object
 */
function ReportingOptions(config) {
    this.config = config;
}

/**
 * returns the kind of information to be printed on the console. May be one
 * of `summary`, `detail`, `both` or `none`. Used by the
 * `cover` command.
 * @method print
 * @return {String} the kind of information to print to the console at the end
 * of the `cover` command execution.
 */
/**
 * returns a list of reports that should be generated at the end of a run. Used
 * by the `cover` and `report` commands.
 * @method reports
 * @return {Array} an array of reports that should be produced
 */
/**
 * returns the directory under which reports should be generated. Used by the
 * `cover` and `report` commands.
 *
 * @method dir
 * @return {String} the directory under which reports should be generated.
 */
/**
 * returns an object that has keys that are report format names and values that are objects
 * containing detailed configuration for each format. Running `istanbul help config`
 * will give you all the keys per report format that can be overridden.
 * Used by the `cover` and `report` commands.
 * @method reportConfig
 * @return {Object} detailed report configuration per report format.
 */
addMethods(ReportingOptions, 'print', 'reports', 'dir', 'reportConfig');

function isInvalidMark(v, key) {
    var prefix = 'Watermark for [' + key + '] :';

    if (v.length !== 2) {
        return prefix + 'must be an array of length 2';
    }
    v[0] = Number(v[0]);
    v[1] = Number(v[1]);

    if (isNaN(v[0]) || isNaN(v[1])) {
        return prefix + 'must have valid numbers';
    }
    if (v[0] < 0 || v[1] < 0) {
        return prefix + 'must be positive numbers';
    }
    if (v[1] > 100) {
        return prefix + 'cannot exceed 100';
    }
    if (v[1] <= v[0]) {
        return prefix + 'low must be less than high';
    }
    return null;
}

/**
 * returns the low and high watermarks to be used to designate whether coverage
 * is `low`, `medium` or `high`. Statements, functions, branches and lines can
 * have independent watermarks. These are respected by all reports
 * that color for low, medium and high coverage. See the default configuration for exact syntax
 * using `istanbul help config`. Used by the `cover` and `report` commands.
 *
 * @method watermarks
 * @return {Object} an object containing low and high watermarks for statements,
 *  branches, functions and lines.
 */
ReportingOptions.prototype.watermarks = function () {
    var v = this.config.watermarks,
        defs = defaults.watermarks(),
        ret = {};

    Object.keys(defs).forEach(function (k) {
        var mark = v[k], //it will already be a non-zero length array because of the way the merge works
            message = isInvalidMark(mark, k);
        if (message) {
            console.error(message);
            ret[k] = defs[k];
        } else {
            ret[k] = mark;
        }
    });
    return ret;
};

/**
 * Object that returns hook options. Note that istanbul does not provide an
 * option to hook `require`. This is always done by the `cover` command.
 * @class HookOptions
 * @module config
 * @constructor
 * @param config the hooks part of the config object
 */
function HookOptions(config) {
    this.config = config;
}

/**
 * returns if `vm.runInThisContext` needs to be hooked, in addition to the standard
 * `require` hooks added by istanbul. This should be true for code that uses
 * RequireJS for example. Used by the `cover` command.
 * @method hookRunInContext
 * @return {Boolean} true if `vm.runInThisContext` needs to be hooked for coverage
 */
/**
 * returns a path to JS file or a dependent module that should be used for
 * post-processing files after they have been required. See the `yui-istanbul` module for
 * an example of a post-require hook. This particular hook modifies the yui loader when
 * that file is required to add istanbul interceptors. Use by the `cover` command
 *
 * @method postRequireHook
 * @return {String} a path to a JS file or the name of a node module that needs
 * to be used as a `require` post-processor
 */
/**
 * returns if istanbul needs to add a SIGINT (control-c, usually) handler to
 * save coverage information. Useful for getting code coverage out of processes
 * that run forever and need a SIGINT to terminate.
 * @method handleSigint
 * @return {Boolean} true if SIGINT needs to be hooked to write coverage information
 */

addMethods(HookOptions, 'hookRunInContext', 'postRequireHook', 'handleSigint');

/**
 * represents the istanbul configuration and provides sub-objects that can
 * return instrumentation, reporting and hook options respectively.
 * Usage
 * -----
 *
 *      var configObj = require('istanbul').config.loadFile();
 *
 *      console.log(configObj.reporting.reports());
 *
 * @class Configuration
 * @module config
 * @param {Object} obj  the base object to use as the configuration
 * @param {Object} overrides optional - override attributes that are merged into
 *  the base config
 * @constructor
 */
function Configuration(obj, overrides) {

    var config = mergeDefaults(obj, defaultConfig(true));
    if (isObject(overrides)) {
        config = mergeDefaults(overrides, config);
    }
    if (config.verbose) {
        console.error('Using configuration');
        console.error('-------------------');
        console.error(yaml.safeDump(config, { indent: 4, flowLevel: 3 }));
        console.error('-------------------\n');
    }
    this.verbose = config.verbose;
    this.instrumentation = new InstrumentOptions(config.instrumentation);
    this.reporting = new ReportingOptions(config.reporting);
    this.hooks = new HookOptions(config.hooks);
    this.check = config.check; // Pass raw config sub-object.
}

/**
 * true if verbose logging is required
 * @property verbose
 * @type Boolean
 */
/**
 * instrumentation options
 * @property instrumentation
 * @type InstrumentOptions
 */
/**
 * reporting options
 * @property reporting
 * @type ReportingOptions
 */
/**
 * hook options
 * @property hooks
 * @type HookOptions
 */


function loadFile(file, overrides) {
    var defaultConfigFile = path.resolve('.istanbul.yml'),
        configObject;

    if (file) {
        if (!existsSync(file)) {
            throw new Error('Invalid configuration file specified:' + file);
        }
    } else {
        if (existsSync(defaultConfigFile)) {
            file = defaultConfigFile;
        }
    }

    if (file) {
        console.error('Loading config: ' + file);
        configObject = file.match(YML_PATTERN) ?
            yaml.safeLoad(fs.readFileSync(file, 'utf8'), { filename: file }) :
            require(path.resolve(file));
    }

    return new Configuration(configObject, overrides);
}

function loadObject(obj, overrides) {
    return new Configuration(obj, overrides);
}

/**
 * methods to load the configuration object.
 * Usage
 * -----
 *
 *      var config = require('istanbul').config,
 *          configObj = config.loadFile();
 *
 *      console.log(configObj.reporting.reports());
 *
 * @class Config
 * @module main
 * @static
 */
module.exports = {
    /**
     * loads the specified configuration file with optional overrides. Throws
     * when a file is specified and it is not found.
     * @method loadFile
     * @static
     * @param {String} file the file to load. If falsy, the default config file, if present, is loaded.
     *  If not a default config is used.
     * @param {Object} overrides - an object with override keys that are merged into the
     *  config object loaded
     * @return {Configuration} the config object with overrides applied
     */
    loadFile: loadFile,
    /**
     * loads the specified configuration object with optional overrides.
     * @method loadObject
     * @static
     * @param {Object} obj the object to use as the base configuration.
     * @param {Object} overrides - an object with override keys that are merged into the
     *  config object
     * @return {Configuration} the config object with overrides applied
     */
    loadObject: loadObject,
    /**
     * returns the default configuration object. Note that this is a plain object
     * and not a `Configuration` instance.
     * @method defaultConfig
     * @static
     * @return {Object} an object that represents the default config
     */
    defaultConfig: defaultConfig
};