ota-meshiIntroduction
eslint-type-tracer is the type tracer for ESLint rules.
📛 Features
Trace and infer types of expression nodes for ESLint rules.
🚧 Limitations
This tool cannot always infer the complete or exact type of an expression. In particular, ESLint analyzes one file at a time, so types that are defined or imported from other files cannot be inferred. As a result, type inference is limited to what can be determined within the current file only.
💿 Installation
npm install eslint-type-tracerRequirements
- ESLint v8.57.0 and above
- Node.js v14.18.0, v16.0.0 and above
📖 Usage
API
buildTypeTracer
import { buildTypeTracer } from "eslint-type-tracer";Builds a type tracer function for use in ESLint rules. This function infers the type name of a given AST expression node.
Signature:
function buildTypeTracer(
sourceCode: SourceCode
): (node: TSESTree.Expression) => TypeName[];sourceCode: The ESLintSourceCodeobject.
Returns:
A function that takes an expression node and returns an array of inferred type names (e.g., ["Array"]). If the type cannot be determined, it returns an empty array []。
Example:
const typeTrace = buildTypeTracer(context.sourceCode);
const typeNames = typeTrace(node);
if (typeNames.includes("Array")) {
// node is inferred as Array
}buildTypeChecker
import { buildTypeChecker } from "eslint-type-tracer";Builds a type checker function for use in ESLint rules. This function helps you determine if a given AST node is of a specific type.
Signature:
function buildTypeChecker(
sourceCode: SourceCode,
options?: { aggressive?: boolean }
): (
node: TSESTree.Expression,
className: TypeName,
memberAccessNode?: TSESTree.MemberExpression | TSESTree.Property
) => boolean | "aggressive";sourceCode: The ESLintSourceCodeobject.options.aggressive: If set totrue, returns"aggressive"when the type cannot be determined. Default isfalse.
Returns:
A function that takes an expression node, a type name, and optionally a member access node, and returns true if the node is of the specified type, false if not, or "aggressive" if undetermined and the option is set.
Example:
const typeChecker = buildTypeChecker(context.sourceCode);
if (typeChecker(node, "Array")) {
// node is an Array
}🍻 Contributing
Welcome contributing!
Please use GitHub's Issues/PRs.
Development Tools
npm run testruns tests.
🔒 License
See the LICENSE file for license rights and limitations (MIT).