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Add a prefix to Flow specific AST node type #9344
Description
Add a prefix to the type of Node.
- Avoid future conflicts with new ES syntax. Eg: we already support
Matchsyntax, but there is a proposal ECMAScript Pattern Matching, once it reachs higher stage, most likly ESTree will usePatternorMatchas a prefix for these nodes. - Prettier currently supports 330 types of node (exclude 8 from flow v0.294), sometimes it's hard to tell which node is from Flow,
typescript-eslintprefixes the node withTS, and our Angular related node also useNGas a prefix, they are easy to identify.
Activity
[-]Add a prefix to Flow specific node type[/-][+]Add a prefix to Flow specific AST node type[/+]gkz commentedon Dec 18, 2025
Something for us to consider. If we are going to redo our AST node output, now that Flow has adopted most of TypeScript's syntax, should we output
TS-prefixed nodes where the syntax is the same? That would simplify some tooling. There would still be differences that would need to be handled however.fisker commentedon Dec 20, 2025
I'm not sure if this is a good idea.
TSFoowith a parentFLOWBarseems weird to me, and may also confuse.If we want to align with TypeScript, I assume we will follow
typescript-eslint.There are some bad designs for some of their AST shape. For example, the current AST in Flow for
as constmakes more sense to me. I already asked them to update the AST in the past few years, will we strictly follow?On the other hand,
This is true.
So, I'm fine with whatever decision you make.
fisker commentedon Jan 23, 2026
RecordExpressionwas available in babel7, the proposal is dead now. https://github.com/tc39/proposal-record-tuple