logit-js

Logit-js writes informative console logs into javascript files. It can be used as a command line tool or integrated into an editor which is its main use case. It is built upon several small babel plugins in combination with prettier code formatting.

Actively developed. Stable version not yet available.

Current features

• variable logs after basic variable declarations and variable declarations using es6 destructuring
• variable logs after assignment expressions and update expressions
• variable logs of parameter values inside normal functions and arrow functions
• adds line and column number by default
• option --verbose prints function names, typeof info and informative logs inside if statements in region
• option --remove deletes all console logs in region

Input

let bar = 'hello ';
let foo = 'world';
let helloWorld = bar + foo;

const testObject = { hello: 'Hi', world: 'Earth' };
const { hello, world } = testObject;

if (bar.length >= 4) {
    sayHiWithFancyArrowFunction('Alice');
} else if (bar.length < 4) {
    sayHiTo('Bob');
} else {
    sayHiTo('God');
}

function sayHiTo(name) {
    return bar + name;
}
const sayHiWithFancyArrowFunction = name => {
    return bar + name;
};

Output Logit Default

let bar = 'hello ';
console.log('2:0', 'bar :', bar);
let foo = 'world';
console.log('4:0', 'foo :', foo);
let helloWorld = bar + foo;
console.log('6:0', 'helloWorld :', helloWorld);

const testObject = { hello: 'Hi', world: 'Earth' };
console.log('9:0', 'testObject :', testObject);
const { hello, world } = testObject;
console.log('11:0', 'world :', world);
console.log('12:0', 'hello :', hello);

if (bar.length >= 4) {
    sayHiWithFancyArrowFunction('Alice');
} else if (bar.length < 4) {
    sayHiTo('Bob');
} else {
    sayHiTo('God');
}

function sayHiTo(name) {
    console.log('23:4', 'name :', name);
    return bar + name;
}
const sayHiWithFancyArrowFunction = name => {
    console.log('27:4', 'name :', name);
    return bar + name;
};
console.log('30:0', 'sayHiWithFancyArrowFunction :', sayHiWithFancyArrowFunction);

Output Logit Verbose

let bar = 'hello ';
console.log('2:0', 'bar :', bar);
console.log('typeof bar :', typeof bar);
let foo = 'world';
console.log('5:0', 'foo :', foo);
console.log('typeof foo :', typeof foo);
let helloWorld = bar + foo;
console.log('8:0', 'helloWorld :', helloWorld);
console.log('typeof helloWorld :', typeof helloWorld);

const testObject = { hello: 'Hi', world: 'Earth' };
console.log('12:0', 'testObject :', testObject);
console.log('typeof testObject :', typeof testObject);
const { hello, world } = testObject;
console.log('15:0', 'world :', world);
console.log('typeof world :', typeof world);
console.log('17:0', 'hello :', hello);
console.log('typeof hello :', typeof hello);

if (bar.length >= 4) {
    console.log('21:4', 'In IfStatement (bar.length >= 4)');
    sayHiWithFancyArrowFunction('Alice');
} else if (bar.length < 4) {
    console.log('24:4', 'In IfStatement (bar.length < 4)');
    sayHiTo('Bob');
} else {
    console.log('27:4', 'In ElseStatement.');
    sayHiTo('God');
}

function sayHiTo(name) {
    console.log('32:4', 'Function sayHiTo', 'name :', name);
    console.log('typeof name :', typeof name);
    return bar + name;
}
const sayHiWithFancyArrowFunction = name => {
    console.log('37:4', 'Function sayHiWithFancyArrowFunction', 'name :', name);
    console.log('typeof name :', typeof name);
    return bar + name;
};
console.log('41:0', 'sayHiWithFancyArrowFunction :', sayHiWithFancyArrowFunction);
console.log('typeof sayHiWithFancyArrowFunction :', typeof sayHiWithFancyArrowFunction);

Example Usage Emacs

Example Usage Visual Studio Code

Example Usage Atom

Command Line Options

Install

Logit is available as an npm package:

$ npm install logit-js

In order to be able to use the command line it needs to be installed globally:

$ npm install --global logit-js

API

Logit takes a code string as first parameter and an optional options object as a second parameter.

const logit = require('logit-js')

logit("let test = 1;");
// -> {code: "let test = 1;\nconsole.log('2:0', 'test :', test);\n", success: true}

logit("let test = 1;", {verbose: true});
// -> {code: "let test = 5;\nconsole.log('2:0', 'test :', test);\nconsole.log('typeof test :', typeof test);\n"", success: true}

Editor Plugins

• Emacs
• Visual Studio Code
• Atom Contribution by @thomsound

Known Issues

• variables that are assigned return values of update expressions may produce an error and infinite loop

Wishlist

• informative console logs inside try and catch scopes
• option to set customized prettier settings instead of provided default

Contributions

Contributions as well as bug reports are very much welcome.