Browserify transform for unassert: Encourages programming with assertions by providing tools to compile them away.

• unassert: Encourages programming with assertions by providing tools to compile them away.
• babel-plugin-unassert: Babel plugin for unassert
• webpack-unassert-loader: Webpack loader for unassert
• gulp-unassert: Gulp plugin for unassert
• unassert-cli: CLI for unassert
• rollup-plugin-unassert: RollupJS plugin for unassert

$ npm install --save-dev unassertify

$ $(npm bin)/browserify -t unassertify /path/to/src/target.js > /path/to/build/target.js

const source = require('vinyl-source-stream');
const browserify = require('browserify');
const glob = require('glob'),

gulp.task('production_build', function() {
    const files = glob.sync('./src/*.js');
    const b = browserify({entries: files});
    b.transform('unassertify');
    return b.bundle()
        .pipe(source('bundle.js'))
        .pipe(gulp.dest('./dist'));
});

For given math.js below,

'use strict';

const assert = require('node:assert');

function add (a, b) {
    console.assert(typeof a === 'number');
    assert(!isNaN(a));
    assert.equal(typeof b, 'number');
    assert.ok(!isNaN(b));
    return a + b;
}

Run browserify with -t unassertify to transform file.

$ $(npm bin)/browserify -t unassertify /path/to/demo/math.js > /path/to/build/math.js

You will see assert calls disappear.

'use strict';
function add(a, b) {
    return a + b;
}

Assertion expressions are removed when they match patterns below. In other words, unassertify removes assertion calls that are compatible with Node.js standard assert API (and console.assert).

• assert(value, [message])
• assert.ok(value, [message])
• assert.equal(actual, expected, [message])
• assert.notEqual(actual, expected, [message])
• assert.strictEqual(actual, expected, [message])
• assert.notStrictEqual(actual, expected, [message])
• assert.deepEqual(actual, expected, [message])
• assert.notDeepEqual(actual, expected, [message])
• assert.deepStrictEqual(actual, expected, [message])
• assert.notDeepStrictEqual(actual, expected, [message])
• assert.match(string, regexp[, message])
• assert.doesNotMatch(string, regexp[, message])
• assert.throws(block, [error], [message])
• assert.doesNotThrow(block, [message])
• await assert.rejects(asyncFn, [error], [message])
• await assert.doesNotReject(asyncFn, [error], [message])
• assert.fail([message])
• assert.fail(actual, expected, message, operator)
• assert.ifError(value)
• console.assert(value, [message])

unassertify also removes assert variable declarations,

• import assert from "assert"
• import assert from "assert/strict"
• import assert from "node:assert"
• import assert from "node:assert/strict"
• import * as assert from "assert"
• import * as assert from "node:assert"
• import * as assert from "assert/strict"
• import * as assert from "node:assert/strict"
• import { strict as assert } from "assert"
• import { strict as assert } from "node:assert"
• import { default as assert } from "assert"
• import { default as assert } from "node:assert"
• const assert = require("assert")
• const assert = require("node:assert")
• const assert = require("assert/strict")
• const assert = require("node:assert/strict")
• const assert = require("assert").strict
• const assert = require("node:assert").strict
• const { strict: assert } = require("assert")
• const { strict: assert } = require("node:assert")

and assignments.

• assert = require("assert")
• assert = require("node:assert")
• assert = require("assert/strict")
• assert = require("node:assert/strict")
• assert = require("assert").strict
• assert = require("node:assert").strict

unassert automatically removes assertion calls based on their imported variable names.

So if import declaration is as follows,

• import strictAssert, { ok, equal as eq } from 'node:assert/strict';

unassert removes all strictAssert, ok, eq calls.

• Takuto Wada

• Renée Kooi

We support Node under maintenance. In other words, we stop supporting old Node version when their maintenance ends.

This means that any other environment is not supported.

NOTE: If unassertify works in any of the unsupported environments, it is purely coincidental and has no bearing on future compatibility. Use at your own risk.

Licensed under the MIT license.