talend-log

Talend-log - error logging library

A small library that provides redux-logger middleware for error logging to be applied as errorTransformer.

Exports redux-logger compatible error logging middleware.

Minimum-config usage:

your configStore.js file:

import { createStore, applyMiddleware } from 'redux';
import thunkMiddleware from 'redux-thunk';
import promise from 'redux-promise-middleware';
import createLogger from 'redux-logger';
import LOGGING_SERVER_URL from 'somewhere';
import initErrorTransformer, { TraceKit } from 'talend-log';

// important part:
const logger = createLogger({ errorTransformer: initErrorTransformer(LOGGING_SERVER_URL) });
// :end of important part

const createStoreWithMiddleware = applyMiddleware(thunkMiddleware, promise(), logger)(createStore);
export default function configureStore(reducer, initialState) {
    const store = createStoreWithMiddleware(reducer, initialState);
    // drop a reference to store instance for later use in errorLogging reportMiddleware
    TraceKit.store = store;
    return store;
}

Advanced config

Look in ./src/errorTransformer.js for jsDoc on each parameter

import LOGGING_SERVER_URL from 'somewhere';
import initErrorTransformer from 'talend-log';

const logger = createLogger({
    errorTransformer: initErrorTransformer(
        LOGGING_SERVER_URL, {
            send: (payload, fetchOptions) => fetch(LOGGING_SERVER_URL, {
                method: 'POST',
                headers: {
                    'Content-Type': 'application/json'
                },
                body: JSON.stringify({
                    '@message': payload
                }),
                ...fetchOptions,
            }),
            payloadMiddleware: payload => Object.assign({
                state: TraceKit.store.getState()
            }, payload),
            fetchOptions: {
                headers: {
                    'Content-Type': 'application/json',
                    custom: 'customData'
                }
            },
            successHandler: (responseText) => {
                alert('yay! ' + responseText)
            },
            retryCount: 5,
            retryTimeout: 3000,
            failedTryHandler: function failedTry(error, payload, transportOpts, attempt) {
                alert('Oh no! ' + error);
                transportOpts.send(transportOpts.payloadMiddleware(payload), transportOpts.fetchOptions, attempt + 1);
            },
            failedReportHandler: (errorResponse) => {
                alert('oh no! ' + errorResponse)
            },
        }, {
            stackTraceLimit: 100,
            linesOfContext: 13,
            rethrowErrorHandler: () => {},
            remoteFetching: true,
            collectWindowErrors: true,
        }
    )
});

Notable details:

• Once initErrorTransformer is called, listener function is created and registered in TraceKit, then returned.
• Depending on the parameters you provide, TraceKit.report function may be patched to rethrow no error.
• transport.send is called with fetchOptions defined on transport.fetchOptions
• TraceKit.store should be defined in your configStore.js file if you want to attach state to report
• fetchOptions are merged with Object.assign to default options, so don't expect deepMerge
• that is also true for default transport and default options objects

Log warnings

If you have some non-critical exceptions that should be reported, but should not break application, then use a possibility to provide handler for better microcontrol:

in your config file:

import LOGGING_SERVER_URL from 'somewhere';
import initErrorTransformer from 'talend-log';
import transportConfig from 'somewhere';

// this:
initErrorTransformer(LOGGING_SERVER_URL, transportConfig, {
    rethrowErrorHandler: (e) => { if (e.type === 'critical') { throw e; } else { console.error(e); } },
})

somewhere in your application:

import { TraceKit } from 'talend-log';

fetch('google.com').catch(errorResponse => TraceKit.report(new Error(errorResponse)));

Under the hood

TraceKit - Cross browser stack traces. https://github.com/csnover/TraceKit