Node.js Intercept stdout

> intercept-stdout captures or modifies stdout and/or stderr.

> _^{Based on this gist}_

Capture

``javascript
var intercept = require("intercept-stdout"),
captured_text = "";

var unhook_intercept = intercept(function(txt) {
captured_text += txt;
});

console.log("This text is being captured");

// Let's stop capturing stdout.
unhook_intercept();

console.log("This text is not being captured");
`

Modify


`javascript
var intercept = require("intercept-stdout");

var unhook_intercept = intercept(function(txt) {
return txt.replace( /this/i , 'that' );
});

console.log("This text is being modified");
// -> that text is being modified
`

Test

npm install
npm test

Separating Error Text

Starting in Version 0.1.2, you may now specify two interceptor callbacks. If a second interceptor callback is specified, the second callback will be invoked for stderr output.

Errors and Warnings

Versions > 0.1.1 hook both stdout and stderr. This change enables capturing of console.log, console.info, console.warn, and console.error. This change may break pre-existing interceptors if your interceptor expected output to be a full line of text.

About Colorization

Popular modules such as mocha and winston may colorize output by inserting ANSI escape codes into the output stream. Both mocha and winston` make multiple calls to the output streams while colorizing a line -- in order to be robust, your code should anticipate and deal with this.