From 76cb9c2a39d477a64824a985ade40507e3bbade1 Mon Sep 17 00:00:00 2001 From: Adam Mathes Date: Fri, 13 Feb 2026 21:34:48 -0800 Subject: feat(vanilla): add testing infrastructure and tests (NK-wjnczv) --- vanilla/node_modules/estree-walker/README.md | 48 ++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 vanilla/node_modules/estree-walker/README.md (limited to 'vanilla/node_modules/estree-walker/README.md') diff --git a/vanilla/node_modules/estree-walker/README.md b/vanilla/node_modules/estree-walker/README.md new file mode 100644 index 0000000..d739d1b --- /dev/null +++ b/vanilla/node_modules/estree-walker/README.md @@ -0,0 +1,48 @@ +# estree-walker + +Simple utility for walking an [ESTree](https://github.com/estree/estree)-compliant AST, such as one generated by [acorn](https://github.com/marijnh/acorn). + + +## Installation + +```bash +npm i estree-walker +``` + + +## Usage + +```js +var walk = require('estree-walker').walk; +var acorn = require('acorn'); + +ast = acorn.parse(sourceCode, options); // https://github.com/acornjs/acorn + +walk(ast, { + enter(node, parent, prop, index) { + // some code happens + }, + leave(node, parent, prop, index) { + // some code happens + } +}); +``` + +Inside the `enter` function, calling `this.skip()` will prevent the node's children being walked, or the `leave` function (which is optional) being called. + +Call `this.replace(new_node)` in either `enter` or `leave` to replace the current node with a new one. + +Call `this.remove()` in either `enter` or `leave` to remove the current node. + +## Why not use estraverse? + +The ESTree spec is evolving to accommodate ES6/7. I've had a couple of experiences where [estraverse](https://github.com/estools/estraverse) was unable to handle an AST generated by recent versions of acorn, because it hard-codes visitor keys. + +estree-walker, by contrast, simply enumerates a node's properties to find child nodes (and child lists of nodes), and is therefore resistant to spec changes. It's also much smaller. (The performance, if you're wondering, is basically identical.) + +None of which should be taken as criticism of estraverse, which has more features and has been battle-tested in many more situations, and for which I'm very grateful. + + +## License + +MIT -- cgit v1.2.3