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.

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.