TypeScriptToLua · Perryvw · Aug 18, 2019 · May 5, 2019 · May 5, 2019 · May 21, 2019
diff --git a/src/LuaAST.ts b/src/LuaAST.ts
@@ -887,6 +887,9 @@ export function createTableIndexExpression(
 }
 
 export type AssignmentLeftHandSideExpression = Identifier | TableIndexExpression;
+export function isAssignmentLeftHandSideExpression(node: Node): node is AssignmentLeftHandSideExpression {
+    return isIdentifier(node) || isTableIndexExpression(node);
+}
 
 export type FunctionDefinition = (VariableDeclarationStatement | AssignmentStatement) & {
     right: [FunctionExpression];

diff --git a/src/LuaLib.ts b/src/LuaLib.ts
@@ -41,6 +41,7 @@ export enum LuaLibFeature {
     ObjectEntries = "ObjectEntries",
     ObjectFromEntries = "ObjectFromEntries",
     ObjectKeys = "ObjectKeys",
+    ObjectRest = "ObjectRest",
     ObjectValues = "ObjectValues",
     Set = "Set",
     WeakMap = "WeakMap",

diff --git a/src/LuaTransformer.ts b/src/LuaTransformer.ts
diff --git a/src/TSHelper.ts b/src/TSHelper.ts
@@ -60,6 +60,14 @@ export function isAssignmentPattern(node: ts.Node): node is ts.AssignmentPattern
     return ts.isObjectLiteralExpression(node) || ts.isArrayLiteralExpression(node);
 }
 
+export function isDestructuringAssignment(node: ts.Node): node is ts.DestructuringAssignment {
+    return (
+        ts.isBinaryExpression(node) &&
+        node.operatorToken.kind === ts.SyntaxKind.EqualsToken &&
+        isAssignmentPattern(node.left)
+    );
+}
+
 export function getExportable(exportSpecifiers: ts.NamedExports, resolver: EmitResolver): ts.ExportSpecifier[] {
     return exportSpecifiers.elements.filter(exportSpecifier => resolver.isValueAliasDeclaration(exportSpecifier));
 }
@@ -400,7 +408,7 @@ export function getCustomNodeDirectives(node: ts.Node): Map<DecoratorKind, Decor
     const directivesMap = new Map<DecoratorKind, Decorator>();
 
     ts.getJSDocTags(node).forEach(tag => {
-        const tagName = tag.tagName.escapedText as string;
+        const tagName = tag.tagName.text;
         if (Decorator.isValid(tagName)) {
             const dec = new Decorator(tagName, tag.comment ? tag.comment.split(" ") : []);
             directivesMap.set(dec.kind, dec);
@@ -928,34 +936,6 @@ export function moduleHasEmittedBody(
     return false;
 }
 
-export function isValidFlattenableDestructuringAssignmentLeftHandSide(
-    node: ts.DestructuringAssignment,
-    checker: ts.TypeChecker,
-    program: ts.Program
-): boolean {
-    if (ts.isArrayLiteralExpression(node.left)) {
-        if (node.left.elements.length > 0) {
-            return !node.left.elements.some(element => {
-                switch (element.kind) {
-                    case ts.SyntaxKind.Identifier:
-                    case ts.SyntaxKind.PropertyAccessExpression:
-                        if (isArrayLength(element, checker, program)) {
-                            return true;
-                        }
-                    case ts.SyntaxKind.ElementAccessExpression:
-                        // Can be on the left hand side of a Lua assignment statement
-                        return false;
-                    default:
-                        // Cannot be
-                        return true;
-                }
-            });
-        }
-    }
-
-    return false;
-}
-
 export function isArrayLength(
     expression: ts.Expression,
     checker: ts.TypeChecker,
@@ -971,8 +951,10 @@ export function isArrayLength(
     }
 
     const name = ts.isPropertyAccessExpression(expression)
-        ? (expression.name.escapedText as string)
-        : ts.isStringLiteral(expression.argumentExpression) && expression.argumentExpression.text;
+        ? expression.name.text
+        : ts.isStringLiteral(expression.argumentExpression)
+        ? expression.argumentExpression.text
+        : undefined;
 
     return name === "length";
 }

diff --git a/src/TSTLErrors.ts b/src/TSTLErrors.ts
@@ -7,9 +7,6 @@ const getLuaTargetName = (version: LuaTarget) => (version === LuaTarget.LuaJIT ?
 export const CouldNotCast = (castName: string) =>
     new Error(`Failed to cast all elements to expected type using ${castName}.`);
 
-export const ForbiddenEllipsisDestruction = (node: ts.Node) =>
-    new TranspileError(`Ellipsis destruction is not allowed.`, node);
-
 export const ForbiddenForIn = (node: ts.Node) =>
     new TranspileError(`Iterating over arrays with 'for ... in' is not allowed.`, node);
 

diff --git a/src/lualib/ObjectRest.ts b/src/lualib/ObjectRest.ts
@@ -0,0 +1,14 @@
+function __TS__ObjectRest<K extends keyof any, V>(
+    this: void,
+    target: Record<K, V>,
+    usedProperties: Partial<Record<K, true>>
+): Partial<Record<K, V>> {
+    const result: Partial<Record<K, V>> = {};
+    for (const property in target) {
+        if (!usedProperties[property]) {
+            result[property] = target[property];
+        }
+    }
+
+    return result;
+}
diff --git a/test/unit/destructuring.spec.ts b/test/unit/destructuring.spec.ts
@@ -1,6 +1,6 @@
 import * as util from "../util";
 
-const allBindings = "x, y, z";
+const allBindings = "x, y, z, rest";
 const testCases = [
     { binding: "{ x }", value: { x: true } },
     { binding: "{ x, y }", value: { x: false, y: true } },
@@ -9,12 +9,17 @@ const testCases = [
     { binding: "{ x, y = true }", value: { x: false, y: false } },
     { binding: "{ x = true }", value: {} },
     { binding: "{ x, y = true }", value: { x: false } },
+    { binding: "{ ...rest }", value: {} },
+    { binding: "{ x, ...rest }", value: { x: "x" } },
+    { binding: "{ x, ...rest }", value: { x: "x", y: "y", z: "z" } },
 
     { binding: "[]", value: [] },
     { binding: "[x, y]", value: ["x", "y"] },
     { binding: "[x, , y]", value: ["x", "", "y"] },
     { binding: "[x = true]", value: [false] },
     { binding: "[[x, y]]", value: [["x", "y"]] },
+    { binding: "[x, ...rest]", value: ["x"] },
+    { binding: "[x, ...rest]", value: ["x", "y", "z"] },
 
     { binding: "{ y: [z = true] }", value: { y: [false] } },
     { binding: "{ x: [x, y] }", value: { x: ["x", "y"] } },
@@ -47,7 +52,8 @@ test.each(testCases)("in variable declaration (%p)", ({ binding, value }) => {
 });
 
 // TODO: https://github.com/TypeScriptToLua/TypeScriptToLua/issues/695
-test.each(testCases.filter(x => x.binding !== "[x, , y]"))(
+// TODO: https://github.com/microsoft/TypeScript/issues/32656
+test.each(testCases.filter(x => x.binding !== "[x, , y]" && x.binding !== "{ x, ...rest }"))(
     "in exported variable declaration (%p)",
     ({ binding, value }) => {
         util.testModule`