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//// [narrowExceptionVariableInCatchClause.ts]
declare function isFooError(x: any): x is { type: 'foo'; dontPanic(); };
function tryCatch() {
try {
// do stuff...
}
catch (err) { // err is implicitly 'any' and cannot be annotated
if (isFooError(err)) {
err.dontPanic(); // OK
err.doPanic(); // ERROR: Property 'doPanic' does not exist on type '{...}'
}
else if (err instanceof Error) {
err.message;
err.massage; // ERROR: Property 'massage' does not exist on type 'Error'
}
else {
throw err;
}
}
}
//// [narrowExceptionVariableInCatchClause.js]
function tryCatch() {
try {
}
catch (err) {
if (isFooError(err)) {
err.dontPanic(); // OK
err.doPanic(); // ERROR: Property 'doPanic' does not exist on type '{...}'
}
else if (err instanceof Error) {
err.message;
err.massage; // ERROR: Property 'massage' does not exist on type 'Error'
}
else {
throw err;
}
}
}
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