[Tests] more accurate tests

.eslintrc

@@ -5,6 +5,7 @@
 
 	"rules": {
 		"id-length": 0,
+		"multiline-comment-style": "off",
 		"new-cap": [2, {
 			"capIsNewExceptions": [
 				"Get",

package.json

@@ -61,6 +61,9 @@
 		"is-negative-zero": "^2.0.2",
 		"is-string": "^1.0.7"
 	},
+	"testling": {
+		"files": "test/**/*.js"
+	},
 	"auto-changelog": {
 		"output": "CHANGELOG.md",
 		"template": "keepachangelog",

test/implementation.js

@@ -1,18 +1,21 @@
 'use strict';
 
-var indexOf = require('../implementation');
+var implementation = require('../implementation');
 var callBind = require('call-bind');
 var test = require('tape');
+var hasStrictMode = require('has-strict-mode')();
+
 var runTests = require('./tests');
 
 test('as a function', function (t) {
-	t.test('bad array/this value', function (st) {
-		st['throws'](callBind(indexOf, null, undefined, 'a'), TypeError, 'undefined is not an object');
-		st['throws'](callBind(indexOf, null, null, 'a'), TypeError, 'null is not an object');
+	t.test('bad receiver', { skip: !hasStrictMode }, function (st) {
+		/* eslint no-useless-call: 1 */
+		st['throws'](function () { implementation.call(undefined, 'a'); }, TypeError, 'undefined is not an object');
+		st['throws'](function () { implementation.call(null, 'a'); }, TypeError, 'null is not an object');
 		st.end();
 	});
 
-	runTests(callBind(indexOf), t);
+	runTests(callBind(implementation), t);
 
 	t.end();
 });

test/index.js

@@ -1,18 +1,17 @@
 'use strict';
 
-var indexOf = require('..');
-var callBind = require('call-bind');
+var index = require('../');
 var test = require('tape');
 var runTests = require('./tests');
 
 test('as a function', function (t) {
-	t.test('bad array/this value', function (st) {
-		st['throws'](callBind(indexOf, null, undefined, 'a'), TypeError, 'undefined is not an object');
-		st['throws'](callBind(indexOf, null, null, 'a'), TypeError, 'null is not an object');
+	t.test('bad array', function (st) {
+		st['throws'](function () { index(undefined, 'a'); }, TypeError, 'undefined is not an object');
+		st['throws'](function () { index(null, 'a'); }, TypeError, 'null is not an object');
 		st.end();
 	});
 
-	runTests(indexOf, t);
+	runTests(index, t);
 
 	t.end();
 });

test/shimmed.js

@@ -1,5 +1,7 @@
 'use strict';
 
+var orig = Array.prototype.indexOf;
+
 require('../auto');
 
 var test = require('tape');
@@ -13,6 +15,8 @@ var hasStrictMode = require('has-strict-mode')();
 var runTests = require('./tests');
 
 test('shimmed', function (t) {
+	t.comment('shimmed: ' + (orig === Array.prototype.indexOf ? 'no' : 'yes'));
+
 	t.equal(Array.prototype.indexOf.length, 1, 'Array#indexOf has a length of 1');
 	t.test('Function name', { skip: !functionsHaveNames }, function (st) {
 		st.equal(Array.prototype.indexOf.name, 'indexOf', 'Array#indexOf has name "indexOf"');

test/tests.js

@@ -1,14 +1,22 @@
 'use strict';
 
-/*
- * var canDistinguishSparseFromUndefined = 0 in [undefined]; // IE 6 - 8 have a bug where this returns false.
- * var undefinedIfNoSparseBug = canDistinguishSparseFromUndefined ? undefined : { valueOf: function () { return 0; } };
- */
+// var canDistinguishSparseFromUndefined = 0 in [undefined]; // IE 6 - 8 have a bug where this returns false.
+// var undefinedIfNoSparseBug = canDistinguishSparseFromUndefined ? undefined : { valueOf: function () { return 0; } };
+
+// eslint-disable-next-line no-sparse-arrays, array-bracket-spacing
+var holesExist = !(0 in [, ]); // FF 3 fails this check
 
 module.exports = function (indexOf, t) {
 	t.equal(indexOf([], undefined), -1, 'empty array + undefined yields -1');
 	t.equal(indexOf([1], 1), 0, 'array + only item yields its index');
 	t.equal(indexOf([NaN], NaN), -1, 'array with NaN + NaN yields -1');
-	// eslint-disable-next-line no-sparse-arrays
-	t.equal(indexOf([1, , 3], undefined), -1, 'sparse array + undefined yields -1');
+
+	t.equal(
+		indexOf([1, , 3], undefined), // eslint-disable-line no-sparse-arrays
+		-1,
+		'sparse array + undefined yields -1',
+		{ skip: !holesExist }
+	);
+
+	t.equal([0, 1].indexOf(1, 2), -1, 'Firefox 2 bug');
 };