v1.0.0

.gitignore

@@ -1,61 +1,4 @@
-# Logs
-logs
-*.log
-npm-debug.log*
-yarn-debug.log*
-yarn-error.log*
-
-# Runtime data
-pids
-*.pid
-*.seed
-*.pid.lock
-
-# Directory for instrumented libs generated by jscoverage/JSCover
-lib-cov
-
-# Coverage directory used by tools like istanbul
-coverage
-
-# nyc test coverage
-.nyc_output
-
-# Grunt intermediate storage (http://gruntjs.com/creating-plugins#storing-task-files)
-.grunt
-
-# Bower dependency directory (https://bower.io/)
-bower_components
-
-# node-waf configuration
-.lock-wscript
-
-# Compiled binary addons (https://nodejs.org/api/addons.html)
-build/Release
-
-# Dependency directories
+coverage/
 node_modules/
-jspm_packages/
-
-# TypeScript v1 declaration files
-typings/
-
-# Optional npm cache directory
-.npm
-
-# Optional eslint cache
-.eslintcache
-
-# Optional REPL history
-.node_repl_history
-
-# Output of 'npm pack'
-*.tgz
-
-# Yarn Integrity file
-.yarn-integrity
-
-# dotenv environment variables file
-.env
-
-# next.js build output
-.next
+.nyc_output/
+package-lock.json

.travis.yml

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+language: node_js
+node_js:
+  - 8
+  - 10
+  - node
+script: npm run ci

README.md

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-# incomplete-symbol
-Custom-remove features of a Symbol implementation.
+# incomplete-symbol [![NPM Version][npm-image]][npm-url] [![Build Status][travis-image]][travis-url] [![Coverage Status][coveralls-image]][coveralls-url]
+
+> Custom-remove features of a [`Symbol`](https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Symbol) implementation.
+
+
+This is useful when simulating the incomplete `Symbol` implementations available in some of today's modern web browsers.
+
+
+## Installation
+
+[Node.js](http://nodejs.org/) `>= 8` is required. To install, type this at the command line:
+```shell
+npm install incomplete-symbol
+```
+
+
+## Usage
+
+```js
+const customizeSymbol = require('incomplete-symbol');
+
+const exclusions = ['toStringTag'];
+
+const IncompleteSymbol = customizeSymbol(exclusions);
+
+const symbol = new IncompleteSymbol('foo');
+```
+
+
+## Arguments
+
+### `exclusions`
+Type: `Array`  
+Default value: `[]`  
+The output `Symbol` function will not expose each listed property/method.
+
+
+[npm-image]: https://img.shields.io/npm/v/incomplete-symbol.svg
+[npm-url]: https://npmjs.com/package/incomplete-symbol
+[travis-image]: https://img.shields.io/travis/stevenvachon/incomplete-symbol.svg
+[travis-url]: https://travis-ci.org/stevenvachon/incomplete-symbol
+[coveralls-image]: https://img.shields.io/coveralls/stevenvachon/incomplete-symbol.svg
+[coveralls-url]: https://coveralls.io/github/stevenvachon/incomplete-symbol

lib/index.js

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+"use strict";
+const {instanceMethods, instanceProperties, staticMethods, staticProperties} = require("./props");
+
+
+
+const customizeSymbol = (exclusions=[]) =>
+{
+	// For testing: uses the global value when this function is called
+	// instead of when instances are created
+	const globalSymbol = Symbol;
+
+	function IncompleteSymbolInstance(description)
+	{
+		this._symbol = globalSymbol(description);
+
+		instanceMethods
+		.filter(method => !exclusions.includes(method) && typeof this._symbol[method]==="function")
+		.forEach(method => this[method] = (...args) => this._symbol[method](...args));
+
+		instanceProperties
+		.filter(property => !exclusions.includes(property) && this._symbol[property]!==undefined)
+		.forEach(property => Object.defineProperty(this, property,
+		{
+			get: () => this._symbol[property]
+		}));
+	}
+
+	const IncompleteSymbol = (...args) => new IncompleteSymbolInstance(...args);
+
+	staticMethods
+	.filter(method => !exclusions.includes(method) && typeof globalSymbol[method]==="function")
+	.forEach(method => IncompleteSymbol[method] = (...args) => globalSymbol[method](...args));
+
+	staticProperties
+	.filter(property => !exclusions.includes(property) && property in globalSymbol)
+	.forEach(property => Object.defineProperty(IncompleteSymbol, property,
+	{
+		get: () => globalSymbol[property]
+	}));
+
+	return IncompleteSymbol;
+};
+
+
+
+module.exports = customizeSymbol;

lib/props.js

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+"use strict";
+
+
+
+const instanceMethods =
+[
+	"toString",
+	"valueOf",
+	Symbol.toPrimitive
+];
+
+
+
+const instanceProperties =
+[
+	"constructor",
+	"description"
+];
+
+
+
+const staticMethods =
+[
+	"for",
+	"keyFor"
+];
+
+
+
+const staticProperties =
+[
+	"hasInstance",
+	"isConcatSpreadable",
+	"iterator",
+	"length",
+	"match",
+	"replace",
+	"search",
+	"species",
+	"split",
+	"toPrimitive",
+	"toStringTag",
+	"unscopables"
+];
+
+
+
+module.exports =
+{
+	instanceMethods,
+	instanceProperties,
+	staticMethods,
+	staticProperties
+};

package.json

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+{
+  "name": "incomplete-symbol",
+  "description": "Custom-remove features of a Symbol implementation.",
+  "version": "1.0.0",
+  "license": "MIT",
+  "author": "Steven Vachon <contact@svachon.com> (https://www.svachon.com/)",
+  "repository": "github:stevenvachon/incomplete-symbol",
+  "main": "lib",
+  "devDependencies": {
+    "chai": "^4.2.0",
+    "coveralls": "^3.0.2",
+    "mocha": "^5.2.0",
+    "nyc": "^13.1.0",
+    "sinon": "^7.2.2",
+    "sinon-chai": "^3.3.0",
+    "symbol.prototype.description": "^1.0.0"
+  },
+  "engines": {
+    "node": ">= 8"
+  },
+  "scripts": {
+    "ci": "npm run test && nyc report --reporter=text-lcov | coveralls",
+    "posttest": "nyc report --reporter=html",
+    "test": "nyc --reporter=text-summary mocha test --check-leaks --bail"
+  },
+  "files": [
+    "lib"
+  ],
+  "keywords": [
+    "symbol"
+  ]
+}

test.js

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+"use strict";
+const customizeSymbol = require("./lib");
+const {afterEach, beforeEach, describe, it} = require("mocha");
+const {expect} = require("chai").use( require("sinon-chai") );
+const {instanceMethods, instanceProperties, staticMethods, staticProperties} = require("./lib/props");
+const {restore, stub} = require("sinon");
+require("symbol.prototype.description/auto");
+
+
+
+const instanceKeys = [...instanceMethods, ...instanceProperties];
+
+const propertyString = key => typeof key === "symbol" ? key.description : `"${key}"`;
+
+const removeExtendableKeys = keys => keys.filter(key => unextendableKeys.includes(key));
+const removeUnextendableKeys = keys => keys.filter(key => !unextendableKeys.includes(key));
+
+const staticKeys = [...staticMethods, ...staticProperties];
+const symbolString = "description";
+
+const unextendableKeys =
+[
+	"constructor",
+	"length",
+	"toString",
+	"valueOf"
+];
+
+
+
+describe("Default behavior", () =>
+{
+	it("is the same as the global", () =>
+	{
+		const IncompleteSymbol = customizeSymbol();
+
+		const symbol = IncompleteSymbol(symbolString);
+
+		instanceKeys.forEach(key => expect(symbol).to.have.property(key));
+		staticKeys.forEach(key => expect(IncompleteSymbol).to.have.property(key));
+
+		const args = ["arg1", "arg2"];
+
+		instanceMethods.forEach(method =>
+		{
+			stub(Symbol.prototype, method);
+
+			symbol[method](...args);
+
+			expect(Symbol.prototype[method]).to.have.been.calledWith(...args);
+
+			restore();
+		});
+
+		staticMethods.forEach(method =>
+		{
+			stub(Symbol, method);
+
+			IncompleteSymbol[method](...args);
+
+			expect(Symbol[method]).to.have.been.calledWith(...args);
+
+			restore();
+		});
+	});
+});
+
+
+
+describe("Unavailable properties/methods", () =>
+{
+	const originalSymbol = Symbol;
+
+
+
+	beforeEach(() =>
+	{
+		const stubbedSymbol = customizeSymbol(
+		[
+			"description",
+			"for",
+			"hasInstance",
+			Symbol.toPrimitive
+		]);
+
+		stub(global, "Symbol").callsFake(stubbedSymbol);
+	});
+
+	afterEach(() => restore());
+
+
+
+	it("does not attempt to wrap them", () =>
+	{
+		const IncompleteSymbol = customizeSymbol();
+
+		const symbol = IncompleteSymbol(symbolString);
+
+		expect(IncompleteSymbol).to.not.have.property("for");
+		expect(IncompleteSymbol).to.not.have.property("hasInstance");
+		expect(symbol).to.not.have.property("description");
+		expect(symbol).to.not.have.property(originalSymbol.toPrimitive);
+	})
+});
+
+
+
+describe("Exclusions", () =>
+{
+	removeUnextendableKeys(instanceKeys).forEach(key => it(propertyString(key), () =>
+	{
+		const IncompleteSymbol = customizeSymbol([key]);
+
+		const symbol = IncompleteSymbol(symbolString);
+
+		expect(symbol).to.not.have.property(key);
+	}));
+
+
+
+	removeUnextendableKeys(staticKeys).forEach(key => it(propertyString(key), () =>
+	{
+		const IncompleteSymbol = customizeSymbol([key]);
+
+		expect(IncompleteSymbol).to.not.have.property(key);
+	}));
+
+
+
+	it("all methods/properties", () =>
+	{
+		const IncompleteSymbol = customizeSymbol([...instanceKeys, ...staticKeys]);
+
+		const symbol = IncompleteSymbol(symbolString);
+
+		removeExtendableKeys(instanceKeys).forEach(key => expect(symbol).to.have.property(key));
+		removeExtendableKeys(staticKeys).forEach(key => expect(IncompleteSymbol).to.have.property(key));
+
+		removeUnextendableKeys(instanceKeys).forEach(key => expect(symbol).to.not.have.property(key));
+		removeUnextendableKeys(staticKeys).forEach(key => expect(IncompleteSymbol).to.not.have.property(key));
+	});
+});