assert-code-frame

Enhances Node.js's built-in assert module by printing a code frame along with the error message when an assertion fails. This makes it easier to identify the location of the failed assertion in your code.

Installation

npm install assert-code-frame

Usage

import assert from 'assert-code-frame';

assert.strictEqual(1 + 1, 3, '1 + 1 should be 3');

Will output:

AssertionError [ERR_ASSERTION]: 1 + 1 should be 3

2 !== 3

    at Proxy.<anonymous> (assert-code-frame/src/index.ts:65:17)
    at Object.<anonymous> (assert-code-frame/example.ts:3:8)
    at Module._compile (node:internal/modules/cjs/loader:1469:14)
    at Module._compile (assert-code-frame/node_modules/esbuild-register/dist/node.js:2258:26)
    at Module._extensions..js (node:internal/modules/cjs/loader:1548:10)
    at Object.newLoader [as .ts] (assert-code-frame/node_modules/esbuild-register/dist/node.js:2262:9)
    at Module.load (node:internal/modules/cjs/loader:1288:32)
    at Module._load (node:internal/modules/cjs/loader:1104:12)
    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:173:12)
    at node:internal/main/run_main_module:28:49

  1 | import assert from './src';
  2 |
> 3 | assert.strictEqual(1 + 1, 3, '1 + 1 should be 3');
    |        ^ 1 + 1 should be 3

2 !== 3

  4 | {
  generatedMessage: false,
  code: 'ERR_ASSERTION',
  actual: 2,
  expected: 3,
  operator: 'strictEqual'
}

When an assertion fails, the code frame will be printed to the console, highlighting the line of code where the assertion failed.

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

License

MIT