Tests WIP 2

test/with.test.js

@@ -68,6 +68,184 @@ describe('with statements', () => {
 			}
 		});
 
+		describe('allows access to `this`', () => {
+			itSerializes('when `with ()` not included in output', {
+				in() {
+					function outer() {
+						with ({this: 2, a: 3}) {
+							return () => this;
+						}
+					}
+					return outer.call({x: 1});
+				},
+				out: '(_a=>function(){return()=>this}.call(_a))({x:1})',
+				validate(fn) {
+					expect(fn).toBeFunction();
+					expect(fn()).toEqual({x: 1});
+				}
+			});
+
+			itSerializes('when `with ()` included in output', {
+				in() {
+					const y = 2;
+					function outer() {
+						with ({this: 2, a: 3}) {
+							return () => [this, y];
+						}
+					}
+					return outer.call({x: 1});
+				},
+				out: `
+					(y=>_a=>function(){
+						return a=>{
+							with(a)return()=>[this,y]
+						}
+					}.call(_a))(2)({x:1})({this:2,a:3})
+				`,
+				validate(fn) {
+					expect(fn).toBeFunction();
+					expect(fn()).toEqual([{x: 1}, 2]);
+				}
+			});
+		});
+
+		describe('allows access to `arguments`', () => {
+			itSerializes('in sloppy mode function', {
+				in() {
+					function outer() {
+						with ({a: 4}) {
+							return () => arguments; // eslint-disable-line prefer-rest-params
+						}
+					}
+					return outer(1, 2, 3);
+				},
+				out: '(arguments=>a=>{with(a)return()=>arguments})(function(){return arguments}(1,2,3))({a:4})',
+				validate(fn) {
+					expect(fn).toBeFunction();
+					const args = fn();
+					expect(args).toBeArguments();
+					expect([...args]).toEqual([1, 2, 3]);
+				}
+			});
+
+			itSerializes('in strict mode function', {
+				in() {
+					function outer() {
+						with ({a: 4}) {
+							return () => {
+								'use strict';
+
+								return arguments; // eslint-disable-line prefer-rest-params
+							};
+						}
+					}
+					return outer(1, 2, 3);
+				},
+				out: `
+					(arguments=>a=>{
+						with(a)return()=>{"use strict";return arguments}
+					})(function(){return arguments}(1,2,3))({a:4})
+				`,
+				validate(fn) {
+					expect(fn).toBeFunction();
+					const args = fn();
+					expect(args).toBeArguments();
+					expect([...args]).toEqual([1, 2, 3]);
+				}
+			});
+		});
+
+		describe('allows access to `this` and `arguments` together', () => {
+			itSerializes('in sloppy mode function', {
+				in() {
+					function outer() {
+						with ({a: 4}) {
+							return () => [this, arguments]; // eslint-disable-line prefer-rest-params
+						}
+					}
+					return outer.call({x: 1}, 2, 3, 4);
+				},
+				out: `
+					(
+						(_a,_b)=>function(){
+							return a=>{
+								with(a)return()=>[this,arguments]
+							}
+						}.apply(_a,_b)
+					)({x:1},function(){return arguments}(2,3,4))({a:4})
+				`,
+				validate(fn) {
+					expect(fn).toBeFunction();
+					const [that, args] = fn();
+					expect(that).toEqual({x: 1});
+					expect(args).toBeArguments();
+					expect([...args]).toEqual([2, 3, 4]);
+				}
+			});
+
+			itSerializes('in strict mode function', {
+				in() {
+					function outer() {
+						with ({a: 4}) {
+							return () => {
+								'use strict';
+
+								return [this, arguments]; // eslint-disable-line prefer-rest-params
+							};
+						}
+					}
+					return outer.call({x: 1}, 2, 3, 4);
+				},
+				out: `
+					(
+						(_a,_b)=>function(){
+							return a=>{
+								with(a)return()=>{
+									"use strict";
+									return[this,arguments]
+								}
+							}
+						}.apply(_a,_b)
+					)({x:1},function(){return arguments}(2,3,4))({a:4})
+				`,
+				validate(fn) {
+					expect(fn).toBeFunction();
+					const [that, args] = fn();
+					expect(that).toEqual({x: 1});
+					expect(args).toBeArguments();
+					expect([...args]).toEqual([2, 3, 4]);
+				}
+			});
+		});
+
+		itSerializes('allows access to `this` when `arguments` also in scope tree', {
+			in() {
+				function outer() {
+					let f;
+					with ({x: 1}) f = (0, () => [x, this]); // eslint-disable-line no-undef
+					return [f, () => arguments]; // eslint-disable-line prefer-rest-params
+				}
+				return outer.call({y: 2}, 3, 4, 5);
+			},
+			out: `(()=>{
+				const a=(
+					(_a,b)=>function(){
+						return[
+							()=>b,
+							a=>{with(a)return()=>[x,this]}
+						]
+					}.call(_a)
+				)({y:2},function(){return arguments}(3,4,5));return[a[1]({x:1}),a[0]]
+			})()`,
+			validate([fn1, fn2]) {
+				expect(fn1).toBeFunction();
+				expect(fn1()).toEqual([1, {y: 2}]);
+				const args = fn2();
+				expect(args).toBeArguments();
+				expect([...args]).toEqual([3, 4, 5]);
+			}
+		});
+
 		itSerializes('Alters scope when `with` object property changed', {
 			in() {
 				const obj = {x: 123},