tsd
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Check TypeScript type definitions
47 lines (46 loc) • 2.26 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.strictAssertion = void 0;
const utils_1 = require("../../utils");
/**
* Performs strict type assertion between the argument if the assertion, and the generic type of the assertion.
*
* @param checker - The TypeScript type checker.
* @param nodes - The `expectType` AST nodes.
* @return List of custom diagnostics.
*/
const strictAssertion = (checker, nodes) => {
const diagnostics = [];
if (!nodes) {
return diagnostics;
}
for (const node of nodes) {
if (!node.typeArguments) {
// Skip if the node does not have generics
continue;
}
// Retrieve the type to be expected. This is the type inside the generic.
const expectedType = checker.getTypeFromTypeNode(node.typeArguments[0]);
const argumentType = checker.getTypeAtLocation(node.arguments[0]);
if (!checker.isTypeAssignableTo(argumentType, expectedType)) {
// The argument type is not assignable to the expected type. TypeScript will catch this for us.
continue;
}
if (!checker.isTypeAssignableTo(expectedType, argumentType)) {
/**
* The expected type is not assignable to the argument type, but the argument type is
* assignable to the expected type. This means our type is too wide.
*/
diagnostics.push((0, utils_1.makeDiagnostic)(node, `Parameter type \`${checker.typeToString(expectedType)}\` is declared too wide for argument type \`${checker.typeToString(argumentType)}\`.`));
}
else if (!checker.isTypeIdenticalTo(expectedType, argumentType)) {
/**
* The expected type and argument type are assignable in both directions. We still have to check
* if the types are identical. See https://github.com/Microsoft/TypeScript/blob/master/doc/spec.md#3.11.2.
*/
diagnostics.push((0, utils_1.makeDiagnostic)(node, `Parameter type \`${checker.typeToString(expectedType)}\` is not identical to argument type \`${checker.typeToString(argumentType)}\`.`));
}
}
return diagnostics;
};
exports.strictAssertion = strictAssertion;