Destructuring consistency fixes (#1417)

- Use AST_Destructuring for lhf assignment patterns
- Use AST_DefaultAssign for default assignments
- Add more checks for lhs expressions
- Add lots of testing
- Cleanup ast (e.g. remove default property)
- Fix #1402 based on a patch from @kzc
- Refine spread allowance in array destructring pattern
- Add destructuring AST tree checker

test/compress/destructuring.js

@@ -50,6 +50,9 @@ destructuring_objects: {
 }
 
 destructuring_objects_trailing_elision: {
+    beautify = {
+        ecma: 6
+    }
     input: {
         var {cc,} = foo;
     }
@@ -57,6 +60,9 @@ destructuring_objects_trailing_elision: {
 }
 
 nested_destructuring_objects: {
+    beautify = {
+        ecma: 6
+    }
     input: {
         const [{a},b] = c;
         let [{a},b] = c;
@@ -66,6 +72,9 @@ nested_destructuring_objects: {
 }
 
 destructuring_constdef_in_loops: {
+    beautify = {
+        ecma: 6
+    }
     input: {
         for (const [x,y] in pairs);
         for (const [a] = 0;;);
@@ -75,6 +84,9 @@ destructuring_constdef_in_loops: {
 }
 
 destructuring_letdef_in_loops: {
+    beautify = {
+        ecma: 6
+    }
     input: {
         for (let [x,y] in pairs);
         for (let [a] = 0;;);
@@ -84,6 +96,9 @@ destructuring_letdef_in_loops: {
 }
 
 destructuring_vardef_in_loops: {
+    beautify = {
+        ecma: 6
+    }
     input: {
         for (var [x,y] in pairs);
         for (var [a] = 0;;);
@@ -200,3 +215,39 @@ destructuring_remove_unused_2: {
         }
     }
 }
+
+object_destructuring_may_need_parentheses: {
+    beautify = {
+        ecma: 6
+    }
+    input: {
+        ({a, b} = {a: 1, b: 2});
+    }
+    expect_exact: "({a,b}={a:1,b:2});"
+}
+
+destructuring_with_undefined_as_default_assignment: {
+    options = {
+        evaluate: true
+    }
+    input: {
+        [foo = undefined] = bar;
+        [foo = void 0] = bar;
+    }
+    expect: {
+        [foo] = bar;
+        [foo] = bar;
+    }
+}
+
+destructuring_dont_evaluate_with_undefined_as_default_assignment: {
+    options = {
+        evaluate: false
+    }
+    input: {
+        [foo = undefined] = bar;
+    }
+    expect: {
+        [foo = void 0] = bar;
+    }
+}

test/compress/issue-203.js

@@ -13,7 +13,11 @@ compress_new_function: {
 
 compress_new_function_with_destruct: {
     options = {
-        unsafe: true
+        unsafe: true,
+        ecma: 6
+    }
+    beautify = {
+        ecma: 6
     }
     input: {
         new Function("aa, [bb]", 'return aa;');

test/compress/new.js

@@ -82,3 +82,19 @@ new_with_unary_prefix: {
     }
     expect_exact: 'var bar=(+new Date).toString(32);';
 }
+
+new_with_assignement_expression: {
+    options = {
+        evaluate: true
+    }
+    input: {
+        var a;
+        new x(a = 5 * 2, b = [1, 2, 3], c = {a: "a", b: "b", cd: "c" + "d"});
+        new y([a, b] = [3, 4]);
+    }
+    expect: {
+        var a;
+        new x(a = 10, b = [1, 2, 3], c = {a: "a", b: "b", cd: "cd"});
+        new y([a, b] = [3, 4]);
+    }
+}

test/compress/object.js

@@ -170,6 +170,9 @@ shorthand_properties: {
 }
 
 concise_methods: {
+    beautify = {
+        ecma: 6
+    }
     input: {
         x = {
             foo(a, b) {
@@ -299,6 +302,9 @@ concise_methods_and_mangle_props: {
 }
 
 concise_generators: {
+    beautify = {
+        ecma: 6
+    }
     input: {
         x = {
             *foo(a, b) {

test/compress/parameters.js

@@ -119,6 +119,9 @@ destructuring_arguments_2: {
 }
 
 destructuring_arguments_3: {
+    beautify = {
+        ecma: 6
+    }
     input: {
         function fn3({x: {y: {z: {} = 42}}}) {}
         const { cover = (function () {}), xCover = (0, function() {})  } = {};
@@ -129,6 +132,9 @@ destructuring_arguments_3: {
 }
 
 default_arguments: {
+    beautify = {
+        ecma: 6
+    }
     input: {
         function x(a = 6) { }
         function x(a = (6 + 5)) { }
@@ -138,6 +144,9 @@ default_arguments: {
 }
 
 default_values_in_destructurings: {
+    beautify = {
+        ecma: 6
+    }
     input: {
         function x({a=(4), b}) {}
         function x([b, c=(12)]) {}

test/compress/template-string.js

@@ -376,4 +376,4 @@ template_ending_with_newline: {
 `;
         };
     } expect_exact: "function foo(e){return`this is a template string!\n`}"
-}
+}

test/compress/try-catch.js

@@ -1,4 +1,7 @@
 catch_destructuring_with_sequence: {
+    beautify = {
+        ecma: 6
+    }
     input: {
         try {
             throw {};