### Installing Kefir via Bower

Source: https://github.com/kefirjs/kefir/blob/master/README.md

This command installs the Kefir library using Bower. It's used for front-end package management, making Kefir available for web projects.

```sh
bower install kefir
```

--------------------------------

### Installing Kefir via NPM

Source: https://github.com/kefirjs/kefir/blob/master/README.md

This command installs the Kefir library using the Node Package Manager (NPM). It adds Kefir as a dependency to your project, making it available for use in JavaScript applications.

```sh
npm install kefir
```

--------------------------------

### Running Kefir Development Scripts

Source: https://github.com/kefirjs/kefir/blob/master/README.md

This snippet lists various `npm run` commands used for Kefir development. These scripts automate tasks such as code formatting (`prettify`), JavaScript bundling (`build-js`), running tests (`test`, `test-only`, `test-debug`), and building documentation (`build-docs`), streamlining the development workflow.

```sh
npm run prettify    # makes source code pretty (you must run it before a PR could be merged)
npm run build-js    # builds js bundlers
npm run test        # runs all the checks
npm run test-only   # runs only unit tests without other checks
npm run test-debug  # runs tests with a chrome inspector connected to the node process
npm run build-docs  # builds the documentation html file
```

--------------------------------

### Using Kefir with Flow Type Checking

Source: https://github.com/kefirjs/kefir/blob/master/README.md

This JavaScript snippet demonstrates how to use Kefir with Flow for type checking. It shows how Flow can infer stream types (e.g., Kefir.Observable<number>) and ensure type safety when working with observable values, improving code reliability.

```js
// @flow

import Kefir from 'kefir'

function foo(numberStream: Kefir.Observable<number>) {
  numberStream.onValue(x => {
    // Flow knows x is a number here
  })
}

const s = Kefir.constant(5)
// Flow can automatically infer the type of values in the stream and determine
// that `s` is of type Kefir.Observable<number> here.
foo(s)
```

--------------------------------

### Checking Awaiting Status with `awaiting` in Kefir.js

Source: https://github.com/kefirjs/kefir/blob/master/deprecated-api-docs.md

Returns a property that represents the awaiting status of two observables, answering whether the primary observable has emitted a value since the last value from the `otherObs` observable was emitted. This method helps track the synchronization or pending state between two observable streams.

```JavaScript
var foo = Kefir.sequentially(100, [1, 2, 3]);
var bar = Kefir.sequentially(100, [1, 2, 3]).delay(40);
var result = foo.awaiting(bar);
result.log();
```

--------------------------------

### Converting Errors to Values with `errorsToValues` in Kefir.js

Source: https://github.com/kefirjs/kefir/blob/master/deprecated-api-docs.md

Converts errors emitted by an observable into values, acting as the inverse of `valuesToErrors`. A custom `handler` function can be provided, which receives the error and must return an object `{convert: Boolean, value: AnyType}`. If `convert` is true, the specified `value` is emitted; otherwise, the original error is passed through.

```JavaScript
var source = Kefir.sequentially(100, [0, -1, 2, -3]).valuesToErrors();
var result = source.errorsToValues(x => {
  return {
    convert: x >= 0,
    value: x * 2
  };
});
result.log();
```

--------------------------------

### Converting Values to Errors with `valuesToErrors` in Kefir.js

Source: https://github.com/kefirjs/kefir/blob/master/deprecated-api-docs.md

Converts values emitted by an observable into errors. By default, all values are converted. A custom `handler` function can be provided, which receives the value and must return an object `{convert: Boolean, error: AnyType}`. If `convert` is true, the specified `error` is emitted; otherwise, the original value is passed through.

```JavaScript
var source = Kefir.sequentially(100, [0, -1, 2, -3]);
var result = source.valuesToErrors(x => {
  return {
    convert: x < 0,
    error: x * 2
  };
});
result.log();
```

--------------------------------

### Ending Observable on First Error with `endOnError` in Kefir.js

Source: https://github.com/kefirjs/kefir/blob/master/deprecated-api-docs.md

Modifies an observable to terminate (end) immediately upon emitting its first error. Subsequent values or errors from the original source will not be propagated after an error occurs.

```JavaScript
var source = Kefir.sequentially(100, [0, -1, 2, -3])
  .valuesToErrors(x => {
    return {convert: x < 0, error: x};
  });
var result = source.endOnError()
result.log();
```

=== COMPLETE CONTENT === This response contains all available snippets from this library. No additional content exists. Do not make further requests.