What is the problem this feature will solve?
Let’s say we have the following test:
import assert from 'node:assert/strict'
import {test} from 'node:test'
test('test', () => {
assert.deepEqual({foo: 1}, {bar: 2})
})This yields:
✖ test (2.74485ms)
AssertionError [ERR_ASSERTION]: Expected values to be strictly deep-equal:
+ actual - expected
{
+ foo: 1
- bar: 2
}
at TestContext.<anonymous> (file:///tmp/test.js:5:10)
at Test.runInAsyncScope (node:async_hooks:203:9)
at Test.run (node:internal/test_runner/test:550:25)
at Test.start (node:internal/test_runner/test:466:17)
at startSubtest (node:internal/test_runner/harness:203:17) {
generatedMessage: true,
code: 'ERR_ASSERTION',
actual: [Object],
expected: [Object],
operator: 'deepStrictEqual'
}
ℹ tests 1
ℹ suites 0
ℹ pass 0
ℹ fail 1
ℹ cancelled 0
ℹ skipped 0
ℹ todo 0
ℹ duration_ms 9.405037
✖ failing tests:
✖ test (2.74485ms)
AssertionError [ERR_ASSERTION]: Expected values to be strictly deep-equal:
+ actual - expected
{
+ foo: 1
- bar: 2
}
at TestContext.<anonymous> (file:///tmp/test.js:5:10)
at Test.runInAsyncScope (node:async_hooks:203:9)
at Test.run (node:internal/test_runner/test:550:25)
at Test.start (node:internal/test_runner/test:466:17)
at startSubtest (node:internal/test_runner/harness:203:17) {
generatedMessage: true,
code: 'ERR_ASSERTION',
actual: [Object],
expected: [Object],
operator: 'deepStrictEqual'
}
Now we want to provide some more context for the assertion, so we add a message.
import assert from 'node:assert/strict'
import {test} from 'node:test'
test('test', () => {
assert.deepEqual({foo: 1}, {bar: 2}, 'objects should be equal')
})Now this yields (the diff is gone):
✖ test (1.631264ms)
AssertionError [ERR_ASSERTION]: objects should be equal
at TestContext.<anonymous> (file:///tmp/test.js:5:10)
at Test.runInAsyncScope (node:async_hooks:203:9)
at Test.run (node:internal/test_runner/test:550:25)
at Test.start (node:internal/test_runner/test:466:17)
at startSubtest (node:internal/test_runner/harness:203:17) {
generatedMessage: false,
code: 'ERR_ASSERTION',
actual: [Object],
expected: [Object],
operator: 'deepStrictEqual'
}
ℹ tests 1
ℹ suites 0
ℹ pass 0
ℹ fail 1
ℹ cancelled 0
ℹ skipped 0
ℹ todo 0
ℹ duration_ms 9.309917
✖ failing tests:
✖ test (1.631264ms)
AssertionError [ERR_ASSERTION]: objects should be equal
at TestContext.<anonymous> (file:///tmp/test.js:5:10)
at Test.runInAsyncScope (node:async_hooks:203:9)
at Test.run (node:internal/test_runner/test:550:25)
at Test.start (node:internal/test_runner/test:466:17)
at startSubtest (node:internal/test_runner/harness:203:17) {
generatedMessage: false,
code: 'ERR_ASSERTION',
actual: [Object],
expected: [Object],
operator: 'deepStrictEqual'
}
Although the intent of adding an assertion message is good, IMO the former is much more useful.
What is the feature you are proposing to solve the problem?
Show both the custom message and the diff. I.e.
✖ test (2.74485ms)
AssertionError [ERR_ASSERTION]: objects should be equal
+ actual - expected
{
+ foo: 1
- bar: 2
}
at TestContext.<anonymous> (file:///tmp/test.js:5:10)
at Test.runInAsyncScope (node:async_hooks:203:9)
at Test.run (node:internal/test_runner/test:550:25)
at Test.start (node:internal/test_runner/test:466:17)
at startSubtest (node:internal/test_runner/harness:203:17) {
generatedMessage: true,
code: 'ERR_ASSERTION',
actual: [Object],
expected: [Object],
operator: 'deepStrictEqual'
}
ℹ tests 1
ℹ suites 0
ℹ pass 0
ℹ fail 1
ℹ cancelled 0
ℹ skipped 0
ℹ todo 0
ℹ duration_ms 9.405037
✖ failing tests:
✖ test (2.74485ms)
AssertionError [ERR_ASSERTION]: objects should be equal
+ actual - expected
{
+ foo: 1
- bar: 2
}
at TestContext.<anonymous> (file:///tmp/test.js:5:10)
at Test.runInAsyncScope (node:async_hooks:203:9)
at Test.run (node:internal/test_runner/test:550:25)
at Test.start (node:internal/test_runner/test:466:17)
at startSubtest (node:internal/test_runner/harness:203:17) {
generatedMessage: true,
code: 'ERR_ASSERTION',
actual: [Object],
expected: [Object],
operator: 'deepStrictEqual'
}
What alternatives have you considered?
None
What is the problem this feature will solve?
Let’s say we have the following test:
This yields:
Now we want to provide some more context for the assertion, so we add a message.
Now this yields (the diff is gone):
Although the intent of adding an assertion message is good, IMO the former is much more useful.
What is the feature you are proposing to solve the problem?
Show both the custom message and the diff. I.e.
What alternatives have you considered?
None