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    server-replay

    Replay server responses from a .har file.

    Useful if…

    • …you want to develop offline and your development server isn't local
    • …your development server is very slow and you want to go faster
    • …you are developing against an API with rate limits

    It works by starting a proxy server and serving content from a previously saved .har file overlayed with files from your local system, configurable with mappings.

    Installation

    npm install -g server-replay
    

    Running

    You need to have a .har file, run server-replay, and then set up your browser to use it as a proxy.

    A .server-replay.json in the current directory is used by default if no config option is given.

    server-replay [options] <.har file>
    
    Options:
      -c, --config  The config file to use
      -p, --port    The port to run the proxy server on  [default: 8080]
      -d, --debug   Turn on debug logging
    

    See the Setup section for details on creating .har file and using the proxy in your browser.

    Configuration

    The config file is a JSON file (plus // comments) with the following properties:

    • version – currently 1
    • mappings – Maps from URLs to file system paths. It is an array of {match, path} objects. match is a string or regex, and path is a string. path can contain $n references to substitute capture groups from match.
    • replacements – Replaces strings in the body of textual content. It is array of {match, replacement} objects. match is a string, regex or variable, and replacement is a string or variable. replacement can contain $n references to substitute capture groups from match.

    Full example:

    {
        "version": 1,
        "mappings": [
            {
                "match": {"regex": ".*\\/static\\/(.*)"},
                "path": "./public/$1"
            }
        ],
        "replacements": [
            // For JSONP requests where callback name is randomly generated
            {
                "match": {"var": "entry.request.parsedUrl.query.callback"},
                "replace": {"var": "request.parsedUrl.query.callback"}
            },
            // Proxy only works over http
            {"match": "https", "replace": "http"}
        ]
    }

    Types

    The types mentioned above take the following forms:

    • string – a plain string. Example: "something".
    • regex – an object with a regex property, and an optional flags property. If you don't provide the flags property, unlike JavaScript, the regex has the global flag set. Example: {"regex": "user\\/([a-z]+)", "flags": "ig"}
    • variable – an object with a var property which contains a path to a value. See below for the available variables. Example: {"var": "request.parsedUrl.query.q"}

    Variables

    • request – the Node request object with the addition of a parsedUrl property, containing the parsed url and query.
    • entry – the HAR entry that is being used to respond to this request. It also has a parsedUrl property, and an indexedHeaders property which maps each header name to it's value(s).

    Setup

    Getting a .har file

    The easiest way is with the Chrome DevTools. In the Network panel disable the cache, refresh the page and interact with the page to generate the network requests that you want to capture. Then right click and select "Save as HAR with Content".

    Creating a .har file

    Note: Extensions such as AdBlock and Ghostery interfere with the recorded responses. Be aware of this and, if necessary, disable them before loading the page.

    Browser proxy configuration

    Chrome

    Launch with the --proxy-server argument:

    /Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome --proxy-server=127.0.0.1:8080
    

    Firefox

    Preferences > Advanced > Network > Settings… > Manual proxy configuration

    Firefox proxy settings

    License

    Copyright 2015 Adobe Systems Incorporated

    This software is licensed under the Apache License, Version 2.0 (see LICENSE file).

    install

    npm i server-replay

    Downloadsweekly downloads

    7

    version

    1.1.0

    license

    Apache-2.0

    homepage

    github.com

    last publish

    collaborators

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