Tools for printing and parsing v8 errors and their stacks
npm install @stack-tools/v8-toolsv8-tools provides utilites for printing and parsing v8 errors and their stacks. If you're not sure if your code will always run in a v8 environment, you will need to know before you use this tool to parse errors. If you are not sure, you should instead use the stack-tools package. Errors that can be parsed by this package will look more or less like this:
``
Error: A message about the error
at someFunction (foo.js:10:2)
at index.js:1:1
v8 is used in many common browsers including including Chrome, Chromium, IE Edge, and Opera, as well as in node. If you are using node however, you should actually use the node-tools package.
The most notable browsers not using v8 are Firefox (using Spidermonkey) and Safari (using JavaScriptCore).
`js
import {
parseErrors,
cleanErrors,
printErrors,
} from '@stack-tools/v8-tools';
try {
doStuff();
} catch (e) {
const errors = parseErrors(e);
cleanErrors(errors);
console.error(printErrors(errors));
}
`
The api for node-tools extends from the stack-tools API. It is capable of more robust parsing though, and can even parse error strings, i.e. parseError(err.stack), which the base stack-tools cannot. Furthermore it provides the most detailed output it can, specifically offering a FrameNode describing content of each frame. When parsing ErrorNode.frames will be an Array. For details of the AST structure please read ast.d.ts.
v8-tools overrides the implementations of some methods from the stack-tools API to provide support for custom chaining prefixes. Custom prefixes are usually the result of user tampering with error.stack, such as is done by nested-error-stacks.
- printErrors(error) returns ${printError(error)}\n${error.prefix}: ${printErrors(error.cause)}
v8-tools also defines the following additional methods:
- parseFrame(frame) returns a FrameNode
- returns true if frame represents a location internal to the v8 runtime.cleanError(error, predicate = isInternalFrame)
- mutates error.stack, filtering out internal frames. Returns error.cleanErrors(errors, predicate = isInternalFrame)
- for each error mutates error.stack, filtering out internal frames. Returns errors`.