@littlethings/coder

LittleCoder

A small and simple code generation tool.

Installation

# With npm
npm install --save @littlethings/coder

# With yarn
yarn add @littlethings/coder

Usage

LittleCoder is a tool that helps you generate code. It is a simple abstraction around writing text, managing indentation and blocks.

Here is an example of using LittleCoder.

import Coder from "@littlethings/coder";

// Create a new instance of Coder.
const coder = new Coder();

// Write a line of code.
coder.line(`console.log("first line of code");`);

// Write an empty line.
coder.line();

// Open a block (takes some text and appends " {").
coder.openBlock("const hello = (name) =>");

// Write some more text.
coder.line("console.log(`Hello, ${name}`);");

// Close the block (*optionally* takes some text and prepends "}").
coder.closeBlock(";");

// Then take the code from the `coder.code` property
console.log(coder.code);

See Output

console.log("first line of code");

const hello = (name) => {
	console.log(`Hello, ${name}`);
};

Constructor

The Coder constructor takes an options argument with two things you can customize:

• indentChar: The character to use for indentation. Defaults to tabs (\t).
• indentAmount: The amount of indentChar characters to print for each indent. Defaults to 1.

These options are both optional and can be specified together, exclusively, or not at all (to use defaults).

// Uses defaults.
new Coder();

// Will use the default `indentChar`, but print
// two of them for each indentation.
new Coder({
	indentAmount: 2,
});

// Will use spaces for indentation, printing four
// of them for each indent.
new Coder({
	indentChar: " ",
	indentAmount: 4,
});

coder.code

This property contains the code written.

const coder = new Coder();

coder.line(`console.log("Hello, World");`);

console.log(coder.code);

See Output

console.log("Hello, World");

coder.line

This method writes a single line of code, ending with \n.

const coder = new Coder();

coder.line(`console.log("Hello, World");`);

console.log(coder.code);

See Output

console.log("Hello, World");

coder.openBlock

A helper method for writing a single line, ending in {\n (note the space before the curly brace). This method also increases the indentation level by one so all future text is written with an indent.

const coder = new Coder();

coder.openBlock("function myFunction()");

coder.closeBlock();

console.log(coder.code);

See Output

function myFunction() {
}

coder.closeBlock

The complement to coder.openBlock. This method reduces the indentation level, then writes a closing curly brace (}) followed by an optional suffix, then \n.

const coder = new Coder();

coder.openBlock("const myFunction = () =>");

coder.closeBlock(";");

console.log(coder.code);

See Output

const myFunction = () => {
};

coder.indent

A utility method to increase the indentation level. Typically this method is not called directly and coder.openBlock is used instead.

const coder = new Coder();

coder.line("const x = {");
coder.indent();
coder.line(`key: "value",`);
coder.dedent();
coder.line("};");

console.log(coder.code);

See Output

const x = {
	key: "value",
};

coder.dedent

A utility method to decrease the indentation level. Typically this method is not called directly and coder.closeBlock is used instead.

const coder = new Coder();

coder.line("const x = {");
coder.indent();
coder.line(`key: "value",`);
coder.dedent();
coder.line("};");

console.log(coder.code);

See Output

const x = {
	key: "value",
};

coder.reset

If you would like to use the same Coder instance multiple times to write different files, you can call coder.reset() to wipe the current code and set the indentation level back to zero.

const coder = new Coder();

coder.line(`console.log("a");`);

// Wipes all state, so any previous changes are lost!
coder.reset();

coder.line(`console.log("b");`);

console.log(coder.code);

See Output

console.log("b");