8 files changed, 1032 insertions, 0 deletions
diff --git a/node_modules/istanbul-lib-report/lib/context.js b/node_modules/istanbul-lib-report/lib/context.js
new file mode 100644
index 0000000..fbb30bc
--- /dev/null
+++ b/node_modules/istanbul-lib-report/lib/context.js
@@ -0,0 +1,132 @@
+'use strict';
+/*
+ Copyright 2012-2015, Yahoo Inc.
+ Copyrights licensed under the New BSD License. See the accompanying LICENSE file for terms.
+ */
+const fs = require('fs');
+const FileWriter = require('./file-writer');
+const XMLWriter = require('./xml-writer');
+const tree = require('./tree');
+const watermarks = require('./watermarks');
+const SummarizerFactory = require('./summarizer-factory');
+
+function defaultSourceLookup(path) {
+    try {
+        return fs.readFileSync(path, 'utf8');
+    } catch (ex) {
+        throw new Error(`Unable to lookup source: ${path} (${ex.message})`);
+    }
+}
+
+function normalizeWatermarks(specified = {}) {
+    Object.entries(watermarks.getDefault()).forEach(([k, value]) => {
+        const specValue = specified[k];
+        if (!Array.isArray(specValue) || specValue.length !== 2) {
+            specified[k] = value;
+        }
+    });
+
+    return specified;
+}
+
+/**
+ * A reporting context that is passed to report implementations
+ * @param {Object} [opts=null] opts options
+ * @param {String} [opts.dir='coverage'] opts.dir the reporting directory
+ * @param {Object} [opts.watermarks=null] opts.watermarks watermarks for
+ *  statements, lines, branches and functions
+ * @param {Function} [opts.sourceFinder=fsLookup] opts.sourceFinder a
+ *  function that returns source code given a file path. Defaults to
+ *  filesystem lookups based on path.
+ * @constructor
+ */
+class Context {
+    constructor(opts) {
+        this.dir = opts.dir || 'coverage';
+        this.watermarks = normalizeWatermarks(opts.watermarks);
+        this.sourceFinder = opts.sourceFinder || defaultSourceLookup;
+        this._summarizerFactory = new SummarizerFactory(
+            opts.coverageMap,
+            opts.defaultSummarizer
+        );
+        this.data = {};
+    }
+
+    /**
+     * returns a FileWriter implementation for reporting use. Also available
+     * as the `writer` property on the context.
+     * @returns {Writer}
+     */
+    getWriter() {
+        return this.writer;
+    }
+
+    /**
+     * returns the source code for the specified file path or throws if
+     * the source could not be found.
+     * @param {String} filePath the file path as found in a file coverage object
+     * @returns {String} the source code
+     */
+    getSource(filePath) {
+        return this.sourceFinder(filePath);
+    }
+
+    /**
+     * returns the coverage class given a coverage
+     * types and a percentage value.
+     * @param {String} type - the coverage type, one of `statements`, `functions`,
+     *  `branches`, or `lines`
+     * @param {Number} value - the percentage value
+     * @returns {String} one of `high`, `medium` or `low`
+     */
+    classForPercent(type, value) {
+        const watermarks = this.watermarks[type];
+        if (!watermarks) {
+            return 'unknown';
+        }
+        if (value < watermarks[0]) {
+            return 'low';
+        }
+        if (value >= watermarks[1]) {
+            return 'high';
+        }
+        return 'medium';
+    }
+
+    /**
+     * returns an XML writer for the supplied content writer
+     * @param {ContentWriter} contentWriter the content writer to which the returned XML writer
+     *  writes data
+     * @returns {XMLWriter}
+     */
+    getXMLWriter(contentWriter) {
+        return new XMLWriter(contentWriter);
+    }
+
+    /**
+     * returns a full visitor given a partial one.
+     * @param {Object} partialVisitor a partial visitor only having the functions of
+     *  interest to the caller. These functions are called with a scope that is the
+     *  supplied object.
+     * @returns {Visitor}
+     */
+    getVisitor(partialVisitor) {
+        return new tree.Visitor(partialVisitor);
+    }
+
+    getTree(name = 'defaultSummarizer') {
+        return this._summarizerFactory[name];
+    }
+}
+
+Object.defineProperty(Context.prototype, 'writer', {
+    enumerable: true,
+    get() {
+        if (!this.data.writer) {
+            this.data.writer = new FileWriter(this.dir);
+        }
+        return this.data.writer;
+    }
+});
+
+module.exports = Context;
diff --git a/node_modules/istanbul-lib-report/lib/file-writer.js b/node_modules/istanbul-lib-report/lib/file-writer.js
new file mode 100644
index 0000000..de1154b
--- /dev/null
+++ b/node_modules/istanbul-lib-report/lib/file-writer.js
@@ -0,0 +1,189 @@
+'use strict';
+/*
+ Copyright 2012-2015, Yahoo Inc.
+ Copyrights licensed under the New BSD License. See the accompanying LICENSE file for terms.
+ */
+const path = require('path');
+const fs = require('fs');
+const mkdirp = require('make-dir');
+const supportsColor = require('supports-color');
+
+/**
+ * Base class for writing content
+ * @class ContentWriter
+ * @constructor
+ */
+class ContentWriter {
+    /**
+     * returns the colorized version of a string. Typically,
+     * content writers that write to files will return the
+     * same string and ones writing to a tty will wrap it in
+     * appropriate escape sequences.
+     * @param {String} str the string to colorize
+     * @param {String} clazz one of `high`, `medium` or `low`
+     * @returns {String} the colorized form of the string
+     */
+    colorize(str /*, clazz*/) {
+        return str;
+    }
+
+    /**
+     * writes a string appended with a newline to the destination
+     * @param {String} str the string to write
+     */
+    println(str) {
+        this.write(`${str}\n`);
+    }
+
+    /**
+     * closes this content writer. Should be called after all writes are complete.
+     */
+    close() {}
+}
+
+/**
+ * a content writer that writes to a file
+ * @param {Number} fd - the file descriptor
+ * @extends ContentWriter
+ * @constructor
+ */
+class FileContentWriter extends ContentWriter {
+    constructor(fd) {
+        super();
+
+        this.fd = fd;
+    }
+
+    write(str) {
+        fs.writeSync(this.fd, str);
+    }
+
+    close() {
+        fs.closeSync(this.fd);
+    }
+}
+
+// allow stdout to be captured for tests.
+let capture = false;
+let output = '';
+
+/**
+ * a content writer that writes to the console
+ * @extends ContentWriter
+ * @constructor
+ */
+class ConsoleWriter extends ContentWriter {
+    write(str) {
+        if (capture) {
+            output += str;
+        } else {
+            process.stdout.write(str);
+        }
+    }
+
+    colorize(str, clazz) {
+        const colors = {
+            low: '31;1',
+            medium: '33;1',
+            high: '32;1'
+        };
+
+        /* istanbul ignore next: different modes for CI and local */
+        if (supportsColor.stdout && colors[clazz]) {
+            return `\u001b[${colors[clazz]}m${str}\u001b[0m`;
+        }
+        return str;
+    }
+}
+
+/**
+ * utility for writing files under a specific directory
+ * @class FileWriter
+ * @param {String} baseDir the base directory under which files should be written
+ * @constructor
+ */
+class FileWriter {
+    constructor(baseDir) {
+        if (!baseDir) {
+            throw new Error('baseDir must be specified');
+        }
+        this.baseDir = baseDir;
+    }
+
+    /**
+     * static helpers for capturing stdout report output;
+     * super useful for tests!
+     */
+    static startCapture() {
+        capture = true;
+    }
+
+    static stopCapture() {
+        capture = false;
+    }
+
+    static getOutput() {
+        return output;
+    }
+
+    static resetOutput() {
+        output = '';
+    }
+
+    /**
+     * returns a FileWriter that is rooted at the supplied subdirectory
+     * @param {String} subdir the subdirectory under which to root the
+     *  returned FileWriter
+     * @returns {FileWriter}
+     */
+    writerForDir(subdir) {
+        if (path.isAbsolute(subdir)) {
+            throw new Error(
+                `Cannot create subdir writer for absolute path: ${subdir}`
+            );
+        }
+        return new FileWriter(`${this.baseDir}/${subdir}`);
+    }
+
+    /**
+     * copies a file from a source directory to a destination name
+     * @param {String} source path to source file
+     * @param {String} dest relative path to destination file
+     * @param {String} [header=undefined] optional text to prepend to destination
+     *  (e.g., an "this file is autogenerated" comment, copyright notice, etc.)
+     */
+    copyFile(source, dest, header) {
+        if (path.isAbsolute(dest)) {
+            throw new Error(`Cannot write to absolute path: ${dest}`);
+        }
+        dest = path.resolve(this.baseDir, dest);
+        mkdirp.sync(path.dirname(dest));
+        let contents;
+        if (header) {
+            contents = header + fs.readFileSync(source, 'utf8');
+        } else {
+            contents = fs.readFileSync(source);
+        }
+        fs.writeFileSync(dest, contents);
+    }
+
+    /**
+     * returns a content writer for writing content to the supplied file.
+     * @param {String|null} file the relative path to the file or the special
+     *  values `"-"` or `null` for writing to the console
+     * @returns {ContentWriter}
+     */
+    writeFile(file) {
+        if (file === null || file === '-') {
+            return new ConsoleWriter();
+        }
+        if (path.isAbsolute(file)) {
+            throw new Error(`Cannot write to absolute path: ${file}`);
+        }
+        file = path.resolve(this.baseDir, file);
+        mkdirp.sync(path.dirname(file));
+        return new FileContentWriter(fs.openSync(file, 'w'));
+    }
+}
+
+module.exports = FileWriter;
diff --git a/node_modules/istanbul-lib-report/lib/path.js b/node_modules/istanbul-lib-report/lib/path.js
new file mode 100644
index 0000000..c928b17
--- /dev/null
+++ b/node_modules/istanbul-lib-report/lib/path.js
@@ -0,0 +1,169 @@
+/*
+ Copyright 2012-2015, Yahoo Inc.
+ Copyrights licensed under the New BSD License. See the accompanying LICENSE file for terms.
+ */
+'use strict';
+
+const path = require('path');
+let parsePath = path.parse;
+let SEP = path.sep;
+const origParser = parsePath;
+const origSep = SEP;
+
+function makeRelativeNormalizedPath(str, sep) {
+    const parsed = parsePath(str);
+    let root = parsed.root;
+    let dir;
+    let file = parsed.base;
+    let quoted;
+    let pos;
+
+    // handle a weird windows case separately
+    if (sep === '\\') {
+        pos = root.indexOf(':\\');
+        if (pos >= 0) {
+            root = root.substring(0, pos + 2);
+        }
+    }
+    dir = parsed.dir.substring(root.length);
+
+    if (str === '') {
+        return [];
+    }
+
+    if (sep !== '/') {
+        quoted = new RegExp(sep.replace(/\W/g, '\\$&'), 'g');
+        dir = dir.replace(quoted, '/');
+        file = file.replace(quoted, '/'); // excessively paranoid?
+    }
+
+    if (dir !== '') {
+        dir = `${dir}/${file}`;
+    } else {
+        dir = file;
+    }
+    if (dir.substring(0, 1) === '/') {
+        dir = dir.substring(1);
+    }
+    dir = dir.split(/\/+/);
+    return dir;
+}
+
+class Path {
+    constructor(strOrArray) {
+        if (Array.isArray(strOrArray)) {
+            this.v = strOrArray;
+        } else if (typeof strOrArray === 'string') {
+            this.v = makeRelativeNormalizedPath(strOrArray, SEP);
+        } else {
+            throw new Error(
+                `Invalid Path argument must be string or array:${strOrArray}`
+            );
+        }
+    }
+
+    toString() {
+        return this.v.join('/');
+    }
+
+    hasParent() {
+        return this.v.length > 0;
+    }
+
+    parent() {
+        if (!this.hasParent()) {
+            throw new Error('Unable to get parent for 0 elem path');
+        }
+        const p = this.v.slice();
+        p.pop();
+        return new Path(p);
+    }
+
+    elements() {
+        return this.v.slice();
+    }
+
+    name() {
+        return this.v.slice(-1)[0];
+    }
+
+    contains(other) {
+        let i;
+        if (other.length > this.length) {
+            return false;
+        }
+        for (i = 0; i < other.length; i += 1) {
+            if (this.v[i] !== other.v[i]) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    ancestorOf(other) {
+        return other.contains(this) && other.length !== this.length;
+    }
+
+    descendantOf(other) {
+        return this.contains(other) && other.length !== this.length;
+    }
+
+    commonPrefixPath(other) {
+        const len = this.length > other.length ? other.length : this.length;
+        let i;
+        const ret = [];
+
+        for (i = 0; i < len; i += 1) {
+            if (this.v[i] === other.v[i]) {
+                ret.push(this.v[i]);
+            } else {
+                break;
+            }
+        }
+        return new Path(ret);
+    }
+
+    static compare(a, b) {
+        const al = a.length;
+        const bl = b.length;
+
+        if (al < bl) {
+            return -1;
+        }
+
+        if (al > bl) {
+            return 1;
+        }
+
+        const astr = a.toString();
+        const bstr = b.toString();
+        return astr < bstr ? -1 : astr > bstr ? 1 : 0;
+    }
+}
+
+['push', 'pop', 'shift', 'unshift', 'splice'].forEach(fn => {
+    Object.defineProperty(Path.prototype, fn, {
+        value(...args) {
+            return this.v[fn](...args);
+        }
+    });
+});
+
+Object.defineProperty(Path.prototype, 'length', {
+    enumerable: true,
+    get() {
+        return this.v.length;
+    }
+});
+
+module.exports = Path;
+Path.tester = {
+    setParserAndSep(p, sep) {
+        parsePath = p;
+        SEP = sep;
+    },
+    reset() {
+        parsePath = origParser;
+        SEP = origSep;
+    }
+};
diff --git a/node_modules/istanbul-lib-report/lib/report-base.js b/node_modules/istanbul-lib-report/lib/report-base.js
new file mode 100644
index 0000000..96de750
--- /dev/null
+++ b/node_modules/istanbul-lib-report/lib/report-base.js
@@ -0,0 +1,16 @@
+'use strict';
+
+// TODO: switch to class private field when targetting node.js 12
+const _summarizer = Symbol('ReportBase.#summarizer');
+
+class ReportBase {
+    constructor(opts = {}) {
+        this[_summarizer] = opts.summarizer;
+    }
+
+    execute(context) {
+        context.getTree(this[_summarizer]).visit(this, context);
+    }
+}
+
+module.exports = ReportBase;
diff --git a/node_modules/istanbul-lib-report/lib/summarizer-factory.js b/node_modules/istanbul-lib-report/lib/summarizer-factory.js
new file mode 100644
index 0000000..5e8acd9
--- /dev/null
+++ b/node_modules/istanbul-lib-report/lib/summarizer-factory.js
@@ -0,0 +1,284 @@
+/*
+ Copyright 2012-2015, Yahoo Inc.
+ Copyrights licensed under the New BSD License. See the accompanying LICENSE file for terms.
+ */
+'use strict';
+
+const coverage = require('istanbul-lib-coverage');
+const Path = require('./path');
+const { BaseNode, BaseTree } = require('./tree');
+
+class ReportNode extends BaseNode {
+    constructor(path, fileCoverage) {
+        super();
+
+        this.path = path;
+        this.parent = null;
+        this.fileCoverage = fileCoverage;
+        this.children = [];
+    }
+
+    static createRoot(children) {
+        const root = new ReportNode(new Path([]));
+
+        children.forEach(child => {
+            root.addChild(child);
+        });
+
+        return root;
+    }
+
+    addChild(child) {
+        child.parent = this;
+        this.children.push(child);
+    }
+
+    asRelative(p) {
+        if (p.substring(0, 1) === '/') {
+            return p.substring(1);
+        }
+        return p;
+    }
+
+    getQualifiedName() {
+        return this.asRelative(this.path.toString());
+    }
+
+    getRelativeName() {
+        const parent = this.getParent();
+        const myPath = this.path;
+        let relPath;
+        let i;
+        const parentPath = parent ? parent.path : new Path([]);
+        if (parentPath.ancestorOf(myPath)) {
+            relPath = new Path(myPath.elements());
+            for (i = 0; i < parentPath.length; i += 1) {
+                relPath.shift();
+            }
+            return this.asRelative(relPath.toString());
+        }
+        return this.asRelative(this.path.toString());
+    }
+
+    getParent() {
+        return this.parent;
+    }
+
+    getChildren() {
+        return this.children;
+    }
+
+    isSummary() {
+        return !this.fileCoverage;
+    }
+
+    getFileCoverage() {
+        return this.fileCoverage;
+    }
+
+    getCoverageSummary(filesOnly) {
+        const cacheProp = `c_${filesOnly ? 'files' : 'full'}`;
+        let summary;
+
+        if (Object.prototype.hasOwnProperty.call(this, cacheProp)) {
+            return this[cacheProp];
+        }
+
+        if (!this.isSummary()) {
+            summary = this.getFileCoverage().toSummary();
+        } else {
+            let count = 0;
+            summary = coverage.createCoverageSummary();
+            this.getChildren().forEach(child => {
+                if (filesOnly && child.isSummary()) {
+                    return;
+                }
+                count += 1;
+                summary.merge(child.getCoverageSummary(filesOnly));
+            });
+            if (count === 0 && filesOnly) {
+                summary = null;
+            }
+        }
+        this[cacheProp] = summary;
+        return summary;
+    }
+}
+
+class ReportTree extends BaseTree {
+    constructor(root, childPrefix) {
+        super(root);
+
+        const maybePrefix = node => {
+            if (childPrefix && !node.isRoot()) {
+                node.path.unshift(childPrefix);
+            }
+        };
+        this.visit({
+            onDetail: maybePrefix,
+            onSummary(node) {
+                maybePrefix(node);
+                node.children.sort((a, b) => {
+                    const astr = a.path.toString();
+                    const bstr = b.path.toString();
+                    return astr < bstr
+                        ? -1
+                        : astr > bstr
+                        ? 1
+                        : /* istanbul ignore next */ 0;
+                });
+            }
+        });
+    }
+}
+
+function findCommonParent(paths) {
+    return paths.reduce(
+        (common, path) => common.commonPrefixPath(path),
+        paths[0] || new Path([])
+    );
+}
+
+function findOrCreateParent(parentPath, nodeMap, created = () => {}) {
+    let parent = nodeMap[parentPath.toString()];
+
+    if (!parent) {
+        parent = new ReportNode(parentPath);
+        nodeMap[parentPath.toString()] = parent;
+        created(parentPath, parent);
+    }
+
+    return parent;
+}
+
+function toDirParents(list) {
+    const nodeMap = Object.create(null);
+    list.forEach(o => {
+        const parent = findOrCreateParent(o.path.parent(), nodeMap);
+        parent.addChild(new ReportNode(o.path, o.fileCoverage));
+    });
+
+    return Object.values(nodeMap);
+}
+
+function addAllPaths(topPaths, nodeMap, path, node) {
+    const parent = findOrCreateParent(
+        path.parent(),
+        nodeMap,
+        (parentPath, parent) => {
+            if (parentPath.hasParent()) {
+                addAllPaths(topPaths, nodeMap, parentPath, parent);
+            } else {
+                topPaths.push(parent);
+            }
+        }
+    );
+
+    parent.addChild(node);
+}
+
+function foldIntoOneDir(node, parent) {
+    const { children } = node;
+    if (children.length === 1 && !children[0].fileCoverage) {
+        children[0].parent = parent;
+        return foldIntoOneDir(children[0], parent);
+    }
+    node.children = children.map(child => foldIntoOneDir(child, node));
+    return node;
+}
+
+function pkgSummaryPrefix(dirParents, commonParent) {
+    if (!dirParents.some(dp => dp.path.length === 0)) {
+        return;
+    }
+
+    if (commonParent.length === 0) {
+        return 'root';
+    }
+
+    return commonParent.name();
+}
+
+class SummarizerFactory {
+    constructor(coverageMap, defaultSummarizer = 'pkg') {
+        this._coverageMap = coverageMap;
+        this._defaultSummarizer = defaultSummarizer;
+        this._initialList = coverageMap.files().map(filePath => ({
+            filePath,
+            path: new Path(filePath),
+            fileCoverage: coverageMap.fileCoverageFor(filePath)
+        }));
+        this._commonParent = findCommonParent(
+            this._initialList.map(o => o.path.parent())
+        );
+        if (this._commonParent.length > 0) {
+            this._initialList.forEach(o => {
+                o.path.splice(0, this._commonParent.length);
+            });
+        }
+    }
+
+    get defaultSummarizer() {
+        return this[this._defaultSummarizer];
+    }
+
+    get flat() {
+        if (!this._flat) {
+            this._flat = new ReportTree(
+                ReportNode.createRoot(
+                    this._initialList.map(
+                        node => new ReportNode(node.path, node.fileCoverage)
+                    )
+                )
+            );
+        }
+
+        return this._flat;
+    }
+
+    _createPkg() {
+        const dirParents = toDirParents(this._initialList);
+        if (dirParents.length === 1) {
+            return new ReportTree(dirParents[0]);
+        }
+
+        return new ReportTree(
+            ReportNode.createRoot(dirParents),
+            pkgSummaryPrefix(dirParents, this._commonParent)
+        );
+    }
+
+    get pkg() {
+        if (!this._pkg) {
+            this._pkg = this._createPkg();
+        }
+
+        return this._pkg;
+    }
+
+    _createNested() {
+        const nodeMap = Object.create(null);
+        const topPaths = [];
+        this._initialList.forEach(o => {
+            const node = new ReportNode(o.path, o.fileCoverage);
+            addAllPaths(topPaths, nodeMap, o.path, node);
+        });
+
+        const topNodes = topPaths.map(node => foldIntoOneDir(node));
+        if (topNodes.length === 1) {
+            return new ReportTree(topNodes[0]);
+        }
+
+        return new ReportTree(ReportNode.createRoot(topNodes));
+    }
+
+    get nested() {
+        if (!this._nested) {
+            this._nested = this._createNested();
+        }
+
+        return this._nested;
+    }
+}
+
+module.exports = SummarizerFactory;
diff --git a/node_modules/istanbul-lib-report/lib/tree.js b/node_modules/istanbul-lib-report/lib/tree.js
new file mode 100644
index 0000000..7c18204
--- /dev/null
+++ b/node_modules/istanbul-lib-report/lib/tree.js
@@ -0,0 +1,137 @@
+/*
+ Copyright 2012-2015, Yahoo Inc.
+ Copyrights licensed under the New BSD License. See the accompanying LICENSE file for terms.
+ */
+'use strict';
+
+/**
+ * An object with methods that are called during the traversal of the coverage tree.
+ * A visitor has the following methods that are called during tree traversal.
+ *
+ *   * `onStart(root, state)` - called before traversal begins
+ *   * `onSummary(node, state)` - called for every summary node
+ *   * `onDetail(node, state)` - called for every detail node
+ *   * `onSummaryEnd(node, state)` - called after all children have been visited for
+ *      a summary node.
+ *   * `onEnd(root, state)` - called after traversal ends
+ *
+ * @param delegate - a partial visitor that only implements the methods of interest
+ *  The visitor object supplies the missing methods as noops. For example, reports
+ *  that only need the final coverage summary need implement `onStart` and nothing
+ *  else. Reports that use only detailed coverage information need implement `onDetail`
+ *  and nothing else.
+ * @constructor
+ */
+class Visitor {
+    constructor(delegate) {
+        this.delegate = delegate;
+    }
+}
+
+['Start', 'End', 'Summary', 'SummaryEnd', 'Detail']
+    .map(k => `on${k}`)
+    .forEach(fn => {
+        Object.defineProperty(Visitor.prototype, fn, {
+            writable: true,
+            value(node, state) {
+                if (typeof this.delegate[fn] === 'function') {
+                    this.delegate[fn](node, state);
+                }
+            }
+        });
+    });
+
+class CompositeVisitor extends Visitor {
+    constructor(visitors) {
+        super();
+
+        if (!Array.isArray(visitors)) {
+            visitors = [visitors];
+        }
+        this.visitors = visitors.map(v => {
+            if (v instanceof Visitor) {
+                return v;
+            }
+            return new Visitor(v);
+        });
+    }
+}
+
+['Start', 'Summary', 'SummaryEnd', 'Detail', 'End']
+    .map(k => `on${k}`)
+    .forEach(fn => {
+        Object.defineProperty(CompositeVisitor.prototype, fn, {
+            value(node, state) {
+                this.visitors.forEach(v => {
+                    v[fn](node, state);
+                });
+            }
+        });
+    });
+
+class BaseNode {
+    isRoot() {
+        return !this.getParent();
+    }
+
+    /**
+     * visit all nodes depth-first from this node down. Note that `onStart`
+     * and `onEnd` are never called on the visitor even if the current
+     * node is the root of the tree.
+     * @param visitor a full visitor that is called during tree traversal
+     * @param state optional state that is passed around
+     */
+    visit(visitor, state) {
+        if (this.isSummary()) {
+            visitor.onSummary(this, state);
+        } else {
+            visitor.onDetail(this, state);
+        }
+
+        this.getChildren().forEach(child => {
+            child.visit(visitor, state);
+        });
+
+        if (this.isSummary()) {
+            visitor.onSummaryEnd(this, state);
+        }
+    }
+}
+
+/**
+ * abstract base class for a coverage tree.
+ * @constructor
+ */
+class BaseTree {
+    constructor(root) {
+        this.root = root;
+    }
+
+    /**
+     * returns the root node of the tree
+     */
+    getRoot() {
+        return this.root;
+    }
+
+    /**
+     * visits the tree depth-first with the supplied partial visitor
+     * @param visitor - a potentially partial visitor
+     * @param state - the state to be passed around during tree traversal
+     */
+    visit(visitor, state) {
+        if (!(visitor instanceof Visitor)) {
+            visitor = new Visitor(visitor);
+        }
+        visitor.onStart(this.getRoot(), state);
+        this.getRoot().visit(visitor, state);
+        visitor.onEnd(this.getRoot(), state);
+    }
+}
+
+module.exports = {
+    BaseTree,
+    BaseNode,
+    Visitor,
+    CompositeVisitor
+};
diff --git a/node_modules/istanbul-lib-report/lib/watermarks.js b/node_modules/istanbul-lib-report/lib/watermarks.js
new file mode 100644
index 0000000..fb76082
--- /dev/null
+++ b/node_modules/istanbul-lib-report/lib/watermarks.js
@@ -0,0 +1,15 @@
+'use strict';
+/*
+ Copyright 2012-2015, Yahoo Inc.
+ Copyrights licensed under the New BSD License. See the accompanying LICENSE file for terms.
+ */
+module.exports = {
+    getDefault() {
+        return {
+            statements: [50, 80],
+            functions: [50, 80],
+            branches: [50, 80],
+            lines: [50, 80]
+        };
+    }
+};
diff --git a/node_modules/istanbul-lib-report/lib/xml-writer.js b/node_modules/istanbul-lib-report/lib/xml-writer.js
new file mode 100644
index 0000000..a32550e
--- /dev/null
+++ b/node_modules/istanbul-lib-report/lib/xml-writer.js
@@ -0,0 +1,90 @@
+'use strict';
+/*
+ Copyright 2012-2015, Yahoo Inc.
+ Copyrights licensed under the New BSD License. See the accompanying LICENSE file for terms.
+ */
+const INDENT = '  ';
+
+function attrString(attrs) {
+    return Object.entries(attrs || {})
+        .map(([k, v]) => ` ${k}="${v}"`)
+        .join('');
+}
+
+/**
+ * a utility class to produce well-formed, indented XML
+ * @param {ContentWriter} contentWriter the content writer that this utility wraps
+ * @constructor
+ */
+class XMLWriter {
+    constructor(contentWriter) {
+        this.cw = contentWriter;
+        this.stack = [];
+    }
+
+    indent(str) {
+        return this.stack.map(() => INDENT).join('') + str;
+    }
+
+    /**
+     * writes the opening XML tag with the supplied attributes
+     * @param {String} name tag name
+     * @param {Object} [attrs=null] attrs attributes for the tag
+     */
+    openTag(name, attrs) {
+        const str = this.indent(`<${name + attrString(attrs)}>`);
+        this.cw.println(str);
+        this.stack.push(name);
+    }
+
+    /**
+     * closes an open XML tag.
+     * @param {String} name - tag name to close. This must match the writer's
+     *  notion of the tag that is currently open.
+     */
+    closeTag(name) {
+        if (this.stack.length === 0) {
+            throw new Error(`Attempt to close tag ${name} when not opened`);
+        }
+        const stashed = this.stack.pop();
+        const str = `</${name}>`;
+
+        if (stashed !== name) {
+            throw new Error(
+                `Attempt to close tag ${name} when ${stashed} was the one open`
+            );
+        }
+        this.cw.println(this.indent(str));
+    }
+
+    /**
+     * writes a tag and its value opening and closing it at the same time
+     * @param {String} name tag name
+     * @param {Object} [attrs=null] attrs tag attributes
+     * @param {String} [content=null] content optional tag content
+     */
+    inlineTag(name, attrs, content) {
+        let str = '<' + name + attrString(attrs);
+        if (content) {
+            str += `>${content}</${name}>`;
+        } else {
+            str += '/>';
+        }
+        str = this.indent(str);
+        this.cw.println(str);
+    }
+
+    /**
+     * closes all open tags and ends the document
+     */
+    closeAll() {
+        this.stack
+            .slice()
+            .reverse()
+            .forEach(name => {
+                this.closeTag(name);
+            });
+    }
+}
+
+module.exports = XMLWriter;