Function checkForOfStatement

test/fixtures/snapshot/typescript.js:82841–82894

(node)

            }
        }
        function checkForOfStatement(node) {
            checkGrammarForInOrForOfStatement(node);
            var container = ts.getContainingFunctionOrClassStaticBlock(node);
            if (node.awaitModifier) {
                if (container && ts.isClassStaticBlockDeclaration(container)) {
                    grammarErrorOnNode(node.awaitModifier, ts.Diagnostics.For_await_loops_cannot_be_used_inside_a_class_static_block);
                }
                else {
                    var functionFlags = ts.getFunctionFlags(container);
                    if ((functionFlags & (4 /* FunctionFlags.Invalid */ | 2 /* FunctionFlags.Async */)) === 2 /* FunctionFlags.Async */ && languageVersion < 99 /* ScriptTarget.ESNext */) {
                        // for..await..of in an async function or async generator function prior to ESNext requires the __asyncValues helper
                        checkExternalEmitHelpers(node, 16384 /* ExternalEmitHelpers.ForAwaitOfIncludes */);
                    }
                }
            }
            else if (compilerOptions.downlevelIteration && languageVersion < 2 /* ScriptTarget.ES2015 */) {
                // for..of prior to ES2015 requires the __values helper when downlevelIteration is enabled
                checkExternalEmitHelpers(node, 256 /* ExternalEmitHelpers.ForOfIncludes */);
            }
            // Check the LHS and RHS
            // If the LHS is a declaration, just check it as a variable declaration, which will in turn check the RHS
            // via checkRightHandSideOfForOf.
            // If the LHS is an expression, check the LHS, as a destructuring assignment or as a reference.
            // Then check that the RHS is assignable to it.
            if (node.initializer.kind === 255 /* SyntaxKind.VariableDeclarationList */) {
                checkForInOrForOfVariableDeclaration(node);
            }
            else {
                var varExpr = node.initializer;
                var iteratedType = checkRightHandSideOfForOf(node);
                // There may be a destructuring assignment on the left side
                if (varExpr.kind === 204 /* SyntaxKind.ArrayLiteralExpression */ || varExpr.kind === 205 /* SyntaxKind.ObjectLiteralExpression */) {
                    // iteratedType may be undefined. In this case, we still want to check the structure of
                    // varExpr, in particular making sure it's a valid LeftHandSideExpression. But we'd like
                    // to short circuit the type relation checking as much as possible, so we pass the unknownType.
                    checkDestructuringAssignment(varExpr, iteratedType || errorType);
                }
                else {
                    var leftType = checkExpression(varExpr);
                    checkReferenceExpression(varExpr, ts.Diagnostics.The_left_hand_side_of_a_for_of_statement_must_be_a_variable_or_a_property_access, ts.Diagnostics.The_left_hand_side_of_a_for_of_statement_may_not_be_an_optional_property_access);
                    // iteratedType will be undefined if the rightType was missing properties/signatures
                    // required to get its iteratedType (like [Symbol.iterator] or next). This may be
                    // because we accessed properties from anyType, or it may have led to an error inside
                    // getElementTypeOfIterable.
                    if (iteratedType) {
                        checkTypeAssignableToAndOptionallyElaborate(iteratedType, leftType, varExpr, node.expression);
                    }
                }
            }
            checkSourceElement(node.statement);
            if (node.locals) {
                registerForUnusedIdentifiersCheck(node);
            }
        }
        function checkForInStatement(node) {
            // Grammar checking
            checkGrammarForInOrForOfStatement(node);