test: add tests for null/missing error body in ErrorResponseHandlerV2

frontend/src/api/ErrorResponseHandlerV2.test.ts

@@ -0,0 +1,143 @@
+import { AxiosError } from 'axios';
+import { ErrorV2Resp } from 'types/api';
+import APIError from 'types/api/error';
+
+import { ErrorResponseHandlerV2 } from './ErrorResponseHandlerV2';
+
+function makeAxiosError(
+	overrides: Partial<AxiosError<ErrorV2Resp>>,
+): AxiosError<ErrorV2Resp> {
+	return {
+		isAxiosError: true,
+		name: 'AxiosError',
+		message: 'Request failed',
+		config: {} as any,
+		toJSON: () => ({}),
+		...overrides,
+	} as AxiosError<ErrorV2Resp>;
+}
+
+describe('ErrorResponseHandlerV2', () => {
+	describe('when the server responds with a well-formed error body', () => {
+		it('throws an APIError with fields from response.data.error', () => {
+			const error = makeAxiosError({
+				response: {
+					status: 403,
+					data: {
+						error: {
+							code: 'FORBIDDEN',
+							message: 'only editors/admins can access this resource',
+							url: '/api/v1/dashboards/123',
+							errors: [],
+						},
+					},
+					headers: {} as any,
+					config: {} as any,
+					statusText: 'Forbidden',
+				},
+			});
+
+			expect(() => ErrorResponseHandlerV2(error)).toThrow(APIError);
+			try {
+				ErrorResponseHandlerV2(error);
+			} catch (e) {
+				expect(e).toBeInstanceOf(APIError);
+				const apiError = e as APIError;
+				expect(apiError.getHttpStatusCode()).toBe(403);
+				expect(apiError.getErrorMessage()).toBe(
+					'only editors/admins can access this resource',
+				);
+				expect(apiError.getErrorCode()).toBe('FORBIDDEN');
+			}
+		});
+	});
+
+	describe('when the server responds with a null error body', () => {
+		it('throws an APIError without crashing, using fallback values', () => {
+			const error = makeAxiosError({
+				name: 'AxiosError',
+				message: 'timeout exceeded',
+				response: {
+					status: 504,
+					data: (null as unknown) as ErrorV2Resp,
+					headers: {} as any,
+					config: {} as any,
+					statusText: 'Gateway Timeout',
+				},
+			});
+
+			expect(() => ErrorResponseHandlerV2(error)).toThrow(APIError);
+			try {
+				ErrorResponseHandlerV2(error);
+			} catch (e) {
+				expect(e).toBeInstanceOf(APIError);
+				const apiError = e as APIError;
+				expect(apiError.getHttpStatusCode()).toBe(504);
+				expect(apiError.getErrorMessage()).toBe('timeout exceeded');
+			}
+		});
+
+		it('throws an APIError when response.data.error is missing', () => {
+			const error = makeAxiosError({
+				name: 'AxiosError',
+				message: 'Bad Gateway',
+				response: {
+					status: 502,
+					data: {} as ErrorV2Resp,
+					headers: {} as any,
+					config: {} as any,
+					statusText: 'Bad Gateway',
+				},
+			});
+
+			expect(() => ErrorResponseHandlerV2(error)).toThrow(APIError);
+			try {
+				ErrorResponseHandlerV2(error);
+			} catch (e) {
+				expect(e).toBeInstanceOf(APIError);
+				const apiError = e as APIError;
+				expect(apiError.getHttpStatusCode()).toBe(502);
+			}
+		});
+	});
+
+	describe('when no response is received (network/timeout)', () => {
+		it('throws an APIError using error.message', () => {
+			const error = makeAxiosError({
+				request: {},
+				name: 'ECONNABORTED',
+				message: 'timeout exceeded',
+				status: undefined,
+			});
+
+			expect(() => ErrorResponseHandlerV2(error)).toThrow(APIError);
+			try {
+				ErrorResponseHandlerV2(error);
+			} catch (e) {
+				expect(e).toBeInstanceOf(APIError);
+				const apiError = e as APIError;
+				expect(apiError.getErrorMessage()).toBe('timeout exceeded');
+			}
+		});
+	});
+
+	describe('when the error is a setup error (no request or response)', () => {
+		it('throws an APIError using error.name and error.message', () => {
+			const error = makeAxiosError({
+				name: 'Error',
+				message: 'Something went wrong setting up the request',
+			});
+
+			expect(() => ErrorResponseHandlerV2(error)).toThrow(APIError);
+			try {
+				ErrorResponseHandlerV2(error);
+			} catch (e) {
+				expect(e).toBeInstanceOf(APIError);
+				const apiError = e as APIError;
+				expect(apiError.getErrorMessage()).toBe(
+					'Something went wrong setting up the request',
+				);
+			}
+		});
+	});
+});

frontend/src/api/ErrorResponseHandlerV2.ts

@@ -8,13 +8,14 @@ export function ErrorResponseHandlerV2(error: AxiosError<ErrorV2Resp>): never {
 	// The request was made and the server responded with a status code
 	// that falls out of the range of 2xx
 	if (response) {
+		const errorData = response.data?.error;
 		throw new APIError({
 			httpStatusCode: response.status || 500,
 			error: {
-				code: response.data.error.code,
-				message: response.data.error.message,
-				url: response.data.error.url,
-				errors: response.data.error.errors,
+				code: errorData?.code ?? error.name,
+				message: errorData?.message ?? error.message,
+				url: errorData?.url ?? '',
+				errors: errorData?.errors ?? [],
 			},
 		});
 	}