power-assertの例外処理を見やすくする - Qiita

power-assert is fully compatible with assert. So functions below are also available though they are not enhanced (does not produce descriptive message). assert.fail(actual, expected, message, operator) assert.throws(block, [error], [message]) assert.doesNotThrow(block, [message]) assert.ifError(value) API - power-assert/v1.3.1/README.md とあるように、assert.throwsはテスト失敗時に整形されません。