factory: getLeftmostExpression needs to handle more kinds

[ajafff]

TypeScript Version: 3.0.0-dev.20180621

Search Terms:

Code

import * as ts from 'typescript';
const n = ts.createStatement(ts.createAsExpression(ts.createObjectLiteral(), ts.createTypeReferenceNode('any', undefined)));
ts.createPrinter().printNode(ts.EmitHint.Unspecified, n, ts.createSourceFile('dummy.ts', '', ts.ScriptTarget.Latest));

Expected behavior:

({} as any);

The same applies to NonNullExpression.

Actual behavior:

Invalid code, this is a syntax error: {} as any;

[mhegazy]

PRs welcomed.

[DanielRosenwasser]

I'm surprised we're even making transformations with the printer. Are you sure you're not running this through a transform first?

[ajafff]

@DanielRosenwasser the printer doesn't do anything special here. It's the factory function (in this case createStatement) that adds parentheses if necessary. Except for the example above where no parens are added.

Instead of using the printer, one could also just use isParenthesizedExpression(n.expression)

[DanielRosenwasser]

Gotcha, thanks!