Function checkVarDeclaredNamesNotShadowed

test/fixtures/snapshot/typescript.js:82426–82490

(node)

            }
        }
        function checkVarDeclaredNamesNotShadowed(node) {
            // - ScriptBody : StatementList
            // It is a Syntax Error if any element of the LexicallyDeclaredNames of StatementList
            // also occurs in the VarDeclaredNames of StatementList.
            // - Block : { StatementList }
            // It is a Syntax Error if any element of the LexicallyDeclaredNames of StatementList
            // also occurs in the VarDeclaredNames of StatementList.
            // Variable declarations are hoisted to the top of their function scope. They can shadow
            // block scoped declarations, which bind tighter. this will not be flagged as duplicate definition
            // by the binder as the declaration scope is different.
            // A non-initialized declaration is a no-op as the block declaration will resolve before the var
            // declaration. the problem is if the declaration has an initializer. this will act as a write to the
            // block declared value. this is fine for let, but not const.
            // Only consider declarations with initializers, uninitialized const declarations will not
            // step on a let/const variable.
            // Do not consider const and const declarations, as duplicate block-scoped declarations
            // are handled by the binder.
            // We are only looking for const declarations that step on let\const declarations from a
            // different scope. e.g.:
            //      {
            //          const x = 0; // localDeclarationSymbol obtained after name resolution will correspond to this declaration
            //          const x = 0; // symbol for this declaration will be 'symbol'
            //      }
            // skip block-scoped variables and parameters
            if ((ts.getCombinedNodeFlags(node) & 3 /* NodeFlags.BlockScoped */) !== 0 || ts.isParameterDeclaration(node)) {
                return;
            }
            // skip variable declarations that don't have initializers
            // NOTE: in ES6 spec initializer is required in variable declarations where name is binding pattern
            // so we'll always treat binding elements as initialized
            if (node.kind === 254 /* SyntaxKind.VariableDeclaration */ && !node.initializer) {
                return;
            }
            var symbol = getSymbolOfNode(node);
            if (symbol.flags & 1 /* SymbolFlags.FunctionScopedVariable */) {
                if (!ts.isIdentifier(node.name))
                    return ts.Debug.fail();
                var localDeclarationSymbol = resolveName(node, node.name.escapedText, 3 /* SymbolFlags.Variable */, /*nodeNotFoundErrorMessage*/ undefined, /*nameArg*/ undefined, /*isUse*/ false);
                if (localDeclarationSymbol &&
                    localDeclarationSymbol !== symbol &&
                    localDeclarationSymbol.flags & 2 /* SymbolFlags.BlockScopedVariable */) {
                    if (getDeclarationNodeFlagsFromSymbol(localDeclarationSymbol) & 3 /* NodeFlags.BlockScoped */) {
                        var varDeclList = ts.getAncestor(localDeclarationSymbol.valueDeclaration, 255 /* SyntaxKind.VariableDeclarationList */);
                        var container = varDeclList.parent.kind === 237 /* SyntaxKind.VariableStatement */ && varDeclList.parent.parent
                            ? varDeclList.parent.parent
                            : undefined;
                        // names of block-scoped and function scoped variables can collide only
                        // if block scoped variable is defined in the function\module\source file scope (because of variable hoisting)
                        var namesShareScope = container &&
                            (container.kind === 235 /* SyntaxKind.Block */ && ts.isFunctionLike(container.parent) ||
                                container.kind === 262 /* SyntaxKind.ModuleBlock */ ||
                                container.kind === 261 /* SyntaxKind.ModuleDeclaration */ ||
                                container.kind === 305 /* SyntaxKind.SourceFile */);
                        // here we know that function scoped variable is shadowed by block scoped one
                        // if they are defined in the same scope - binder has already reported redeclaration error
                        // otherwise if variable has an initializer - show error that initialization will fail
                        // since LHS will be block scoped name instead of function scoped
                        if (!namesShareScope) {