chore(types): nicer error class types + jsdocs (#30)

src/error.ts

@@ -4,17 +4,19 @@ import { castToError, Headers } from './core';
 
 export class SteelError extends Error {}
 
-export class APIError extends SteelError {
-  readonly status: number | undefined;
-  readonly headers: Headers | undefined;
-  readonly error: Object | undefined;
-
-  constructor(
-    status: number | undefined,
-    error: Object | undefined,
-    message: string | undefined,
-    headers: Headers | undefined,
-  ) {
+export class APIError<
+  TStatus extends number | undefined = number | undefined,
+  THeaders extends Headers | undefined = Headers | undefined,
+  TError extends Object | undefined = Object | undefined,
+> extends SteelError {
+  /** HTTP status for the response that caused the error */
+  readonly status: TStatus;
+  /** HTTP headers for the response that caused the error */
+  readonly headers: THeaders;
+  /** JSON body of the response that caused the error */
+  readonly error: TError;
+
+  constructor(status: TStatus, error: TError, message: string | undefined, headers: THeaders) {
     super(`${APIError.makeMessage(status, error, message)}`);
     this.status = status;
     this.headers = headers;
@@ -48,7 +50,7 @@ export class APIError extends SteelError {
     message: string | undefined,
     headers: Headers | undefined,
   ): APIError {
-    if (!status) {
+    if (!status || !headers) {
       return new APIConnectionError({ message, cause: castToError(errorResponse) });
     }
 
@@ -90,17 +92,13 @@ export class APIError extends SteelError {
   }
 }
 
-export class APIUserAbortError extends APIError {
-  override readonly status: undefined = undefined;
-
+export class APIUserAbortError extends APIError<undefined, undefined, undefined> {
   constructor({ message }: { message?: string } = {}) {
     super(undefined, undefined, message || 'Request was aborted.', undefined);
   }
 }
 
-export class APIConnectionError extends APIError {
-  override readonly status: undefined = undefined;
-
+export class APIConnectionError extends APIError<undefined, undefined, undefined> {
   constructor({ message, cause }: { message?: string | undefined; cause?: Error | undefined }) {
     super(undefined, undefined, message || 'Connection error.', undefined);
     // in some environments the 'cause' property is already declared
@@ -115,32 +113,18 @@ export class APIConnectionTimeoutError extends APIConnectionError {
   }
 }
 
-export class BadRequestError extends APIError {
-  override readonly status: 400 = 400;
-}
+export class BadRequestError extends APIError<400, Headers> {}
 
-export class AuthenticationError extends APIError {
-  override readonly status: 401 = 401;
-}
+export class AuthenticationError extends APIError<401, Headers> {}
 
-export class PermissionDeniedError extends APIError {
-  override readonly status: 403 = 403;
-}
+export class PermissionDeniedError extends APIError<403, Headers> {}
 
-export class NotFoundError extends APIError {
-  override readonly status: 404 = 404;
-}
+export class NotFoundError extends APIError<404, Headers> {}
 
-export class ConflictError extends APIError {
-  override readonly status: 409 = 409;
-}
+export class ConflictError extends APIError<409, Headers> {}
 
-export class UnprocessableEntityError extends APIError {
-  override readonly status: 422 = 422;
-}
+export class UnprocessableEntityError extends APIError<422, Headers> {}
 
-export class RateLimitError extends APIError {
-  override readonly status: 429 = 429;
-}
+export class RateLimitError extends APIError<429, Headers> {}
 
-export class InternalServerError extends APIError {}
+export class InternalServerError extends APIError<number, Headers> {}