@prebuilder/lib NPM

Prebuilder library

A preprocessing library that allows to resolve C# like preprocessor directives in any text-based input

NB:

It's recommended to use the cjs version of this library, when using it via NodeJS as it uses the more reliable 'path' tool
The esm version needs to be imported from '@prebuilder/lib/dist/index.esm.js'

Install

npm i @prebuilder/lib

Usage Examples

1) Browser:

import preprocess from '@prebuilder/lib/dist/index.esm.js';

// example of code generated at runtime, for ex with a front-end code editor
let codeName = 'User generated script';
let code = `
class MyClass {

#if MY_DIRECTIVE
    myFunction = (data) => {
        return data;
    }
#else
    myFunction = (differentData) => {
        return differentData;
    }
#endif
`;

code = preprocess(code, {defines: ['MY_DIRECTIVE'], log: false, fileAdress: codeName});

// do whatever with processed code

2) Node:

const fs = require('fs');
const preprocess = require('@prebuilder/lib').default;

// read source file
let filePath = 'src/index.js';
let code = fs.readFileSync(filePath, 'utf-8');

code = preprocess(code, {
    defines: ['MY_DIRECTIVE'],
    log: false,
    fileAdress: filePath,
    mode: 'both',
});

// generate processed file
fs.writeFileSync('dist/app.js', code, 'utf-8');

source code:

class MyClass {

// if else directives:
#if MY_DIRECTIVE
    myFunction = (data) => {
        return data;
    }
#else
    myFunction = (differentData) => {
        return differentData;
    }
#endif

// commented mode & negative #if check:
//#if !MY_DIRECTIVE
    myVar = {
        number: 0
    };
//#else
    //#post-code myVar = {
    //#post-code     number: 5
    //#post-code };
//#endif

}

output code :

class MyClass {

    myFunction = (data) => {
        return data;
    }

    myVar = {
        number: 5
    };
}

Options

defines

Required. Type: Array<string>

List of defines based on which to validate #if statements.

log

Type: boolean

Wether to show this process logs or not, like skipped files and number of #if groups found.

filePath

Type: string

Path, Url or name of the script (only needed when logging).

mode

Type: string

Values: "plain"|"commented"|"both"

Wether to preprocess directives written plainly #if or in a comment //#if. Default value is "both".

plain     -> "#if", "#else", ... ("#post-code" not available)

commented -> "//#if", "//#else", ... and "//#post-code let exampleVar = 5;"

v 1.1

Added negative #if check (#if !value)

v 1.2

Added include & exclude files option

v 1.3

Added optional debug logging

v 1.3.1

Improved log messages

v1.3.3

Bugfixes:

Incorrect code output when an if-else statement is unfulfilled

Changes:

Added debug log info on each processed "if group"
Better debug log formatting

v1.4.0

Separated processing functions from plugin in a separate library. This allows for use with node & for other plugins.

v1.5.0

Browser support (esm version now doesn't use any node dependency)

v1.6.0

Added commented directives mode

v1.6.2

Lib refactor + log fixes

v1.6.5

Bugfixes:

Changed an export name to avoid any conflict with a default variable name
Fixed bug when preprocessing without options.filename, while logging is disabled