pelias-mock-logger/README.md

Mock logger for testing logging behavior in Pelias projects

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</p>
<h3 align="center">A modular, open-source search engine for our world.</h3>
<p align="center">Pelias is a geocoder powered completely by open data, available freely to everyone.</p>
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<details open>
<summary>What is Pelias?</summary>
<br />
Pelias is a search engine for places worldwide, powered by open data. It turns addresses and place names into geographic coordinates, and turns geographic coordinates into places and addresses. With Pelias, you're able to turn your users' place searches into actionable geodata and transform your geodata into real places.
<br /><br />
We think open data, open source, and open strategy win over proprietary solutions at any part of the stack and we want to ensure the services we offer are in line with that vision. We believe that an open geocoder improves over the long-term only if the community can incorporate truly representative local knowledge.
</details>

# Pelias Mock Logger


This module is used for testing logging events in Pelias projects.  [proxyquire](https://www.npmjs.com/package/proxyquire)
is the supported module for overriding dependencies in which this module is used.  

## Installation

```bash
$ npm install pelias-mock-logger --save-dev
```

[![NPM](https://nodei.co/npm/pelias-mock-logger.png?downloads=true&stars=true)](https://nodei.co/npm/pelias-mock-logger)

## NPM Module

The `pelias-mock-logger` npm module can be found here:

[https://npmjs.org/package/pelias-mock-logger](https://npmjs.org/package/pelias-mock-logger)

## Usage

Traditionally, testing logging events required quite a bit of setup with proxyquire:

```javascript
const errorMessages = [];

var service = proxyquire('../../../service/interpolation', {
  'pelias-logger': {
    get: () => {
      return {
        error: (msg) => { errorMessages.push(msg); },
        info: (msg) => {}
      };
    }
  }
}).search();

t.deepEquals(errorMessages, ['RequireTransport: failed to connect to interpolation service']);
```

Using the `pelias-mock-logger` module, this code can be shortened to:

```javascript
const logger = require('pelias-mock-logger')();

var adapter = proxyquire('../../../service/interpolation', {
  'pelias-logger': logger
}).search();

t.deepEquals(logger.getErrorMessages(), ['RequireTransport: failed to connect to interpolation service']);
```

## Functions

* logging events
  * `error(msg)`
  * `warn(msg)`
  * `info(msg)`
  * `verbose(msg)`
  * `debug(msg)`
  * `silly(msg)`
* `getLayer()`: returns the value passed to `.get()` in `require( 'pelias-logger' ).get( 'api' )`
* `getLevels()`: returns the supported logging levels: `error`, `warn`, `info`, `verbose`, `debug`, and `silly`
* `getMessages(level, pattern)`: returns all messages logged at a level, optionally matching a pattern
  * Examples:
    * `getMessages('error')`
    * `getMessages('error', /backend error occurred/)`
* `hasMessages(level, pattern)`: returns whether messages were logged at a level, optionally matching a pattern
  * Examples:
    * `hasMessages('error')`
    * `hasMessages('error', /backend error occurred/)`
* `isMessage(level, pattern)`: returns whether the supplied pattern matches or is equal to any messages logged at the specified level
  * Examples
    * `isMessage('error', /backend error occurred)`
    * `isMessage('error', 'a backend error occurred, contact the Pelias team for assistance')`
* level-specific functions
  * getMessages: returns all messages logged at the level specified in function name, optionally matching a pattern
    * `getErrorMessages(pattern)`
    * `getWarnMessages(pattern)`
    * `getInfoMessages(pattern)`
    * `getVerboseMessages(pattern)`
    * `getDebugMessages(pattern)`
    * `getSillyMessages(pattern)`
  * hasMessages: returns whether messages were logged at the level specified in function name, optionally matching a pattern
    * `hasErrorMessages(pattern)`
    * `hasWarnMessages(pattern)`
    * `hasInfoMessages(pattern)`
    * `hasVerboseMessages(pattern)`
    * `hasDebugMessages(pattern)`
    * `hasSillyMessages(pattern)`
  * isMessage: returns whether the supplied pattern matches or is equal to any messages logged at the level specified in the function name
    * `isErrorMessages(pattern)`
    * `isWarnMessages(pattern)`
    * `isInfoMessages(pattern)`
    * `isVerboseMessages(pattern)`
    * `isDebugMessages(pattern)`
    * `isSillyMessages(pattern)`

## Contributing

Please fork and pull request against upstream master on a feature branch.

Provide unit tests in the `test` directory.

### Running Unit Tests

```bash
$ npm test
```