fileseg

File segment fetching and replacing for configuration files

Installation

Simply install by running npm install fileseg --save.

Usage

fileseg allows for configuration block management within files. For instance you may want to control a custom block of ignored paths in a .gitignore file:

node_modules
*.log
.vscode

# __fileseg__ BEGIN:customConfig
some-application-path
another/path
# __fileseg__ END:customConfig

Reading and editing this configuration section is easy with fileseg:

const createAdapter = require("fileseg");

const adapter = createAdapter(".gitignore");
adapter
    .read("customConfig")
    .then(function(config) {
        const newConfig = [
            ...config.split("\n"),
            "somefile.exe"
        ];
        return adapter.write("customConfig", newConfig.join("\n"));
    });

The result within .gitignore would be:

node_modules
*.log
.vscode

# __fileseg__ BEGIN:customConfig
some-application-path
another/path
somefile.exe
# __fileseg__ END:customConfig

A file can have any number of blocks managed by fileseg. A file is created automatically when writing to a path that doesn't exist. Reading a block from a non-existent file will return null by default (this can be overidden in the options).

Configuring

fileseg can be configured by passing in a configuration object when creating the adapter:

const createAdapter = require("fileseg");

const adapter = createAdapter(".gitignore", {
    commentPrefix: "#",
    blockPrefix: " __fileseg__ ",
    beginText: "BEGIN:",
    endText: "END:",
    newLine: "\n",
    noSegment: null
});

You can override the default behaviour:

• commentPrefix is the string used to prefix block delimiters. The default # character is quite common in configuration files, but it can be changed to other comment characters for other markups and languages.
• blockPrefix is a library-specific identifier to increase the uniqueness of the block.
• beginText and endText configure the values to delimit the start and end of a block. These must never be the same and should usually not be changed.
• newLine controls the new line characters (both recognised and replaced). This could be set, for example, to "\r\n" in a pure Windows project.
• noSegment is the default return value for when a segment is not found (includes non-existent files).