Add initial test files from lodash v4. (#4172)

* Install test dependencies.

* Add initial test files.

These files were created using a simplistic AST manipulator using `recast` to
preserve formatting. There's bound to be a huge chunk of errors, but this serves
as a good start. QUnit was replaced with Mocha, with ES2015 imports running via
`esm`.

As far as possible, QUnit-specific syntax has been replaced with Mocha's
`describe` and `it`, while the native Node.js `assert` module is used for
assertions. Files in the `test` directory ending in `.test.js` will be treated
as test files.

* Add initial passing files to test run.

test/bindAll.js

@@ -0,0 +1,74 @@
+import assert from 'assert';
+import lodashStable from 'lodash';
+import { args, toArgs, arrayProto } from './utils.js';
+import bindAll from '../bindAll.js';
+
+describe('bindAll', function() {
+  var args = toArgs(['a']);
+
+  var source = {
+    '_n0': -2,
+    '_p0': -1,
+    '_a': 1,
+    '_b': 2,
+    '_c': 3,
+    '_d': 4,
+    '-0': function() { return this._n0; },
+    '0': function() { return this._p0; },
+    'a': function() { return this._a; },
+    'b': function() { return this._b; },
+    'c': function() { return this._c; },
+    'd': function() { return this._d; }
+  };
+
+  it('should accept individual method names', function() {
+    var object = lodashStable.cloneDeep(source);
+    bindAll(object, 'a', 'b');
+
+    var actual = lodashStable.map(['a', 'b', 'c'], function(key) {
+      return object[key].call({});
+    });
+
+    assert.deepStrictEqual(actual, [1, 2, undefined]);
+  });
+
+  it('should accept arrays of method names', function() {
+    var object = lodashStable.cloneDeep(source);
+    bindAll(object, ['a', 'b'], ['c']);
+
+    var actual = lodashStable.map(['a', 'b', 'c', 'd'], function(key) {
+      return object[key].call({});
+    });
+
+    assert.deepStrictEqual(actual, [1, 2, 3, undefined]);
+  });
+
+  it('should preserve the sign of `0`', function() {
+    var props = [-0, Object(-0), 0, Object(0)];
+
+    var actual = lodashStable.map(props, function(key) {
+      var object = lodashStable.cloneDeep(source);
+      bindAll(object, key);
+      return object[lodashStable.toString(key)].call({});
+    });
+
+    assert.deepStrictEqual(actual, [-2, -2, -1, -1]);
+  });
+
+  it('should work with an array `object`', function() {
+    var array = ['push', 'pop'];
+    bindAll(array);
+    assert.strictEqual(array.pop, arrayProto.pop);
+  });
+
+  it('should work with `arguments` objects as secondary arguments', function() {
+    var object = lodashStable.cloneDeep(source);
+    bindAll(object, args);
+
+    var actual = lodashStable.map(args, function(key) {
+      return object[key].call({});
+    });
+
+    assert.deepStrictEqual(actual, [1]);
+  });
+});