# bun test
Fixes#8768, Fixes#14624, Fixes#20100, Fixes#19875, Fixes#14135,
Fixes#20980, Fixes#21830, Fixes#5738, Fixes#19758, Fixes#12782,
Fixes#5585, Fixes#9548, Might fix 5996
# New features:
## Concurrent tests
Concurrent tests allow running multiple async tests at the same time.
```ts
// concurrent.test.ts
test.concurrent("this takes a while 1", async () => {
await Bun.sleep(1000);
});
test.concurrent("this takes a while 2", async () => {
await Bun.sleep(1000);
});
test.concurrent("this takes a while 3", async () => {
await Bun.sleep(1000);
});
```
Without `.concurrent`, this test file takes 3 seconds to run because
each one has to wait for the one before it to finish before it can
start.
With `.concurrent`, this file takes 1 second because all three sleeps
can run at once.
```
$> bun-after test concurrent
concurrent.test.js:
✓ this takes a while 1 [1005.36ms]
✓ this takes a while 2 [1012.51ms]
✓ this takes a while 3 [1013.15ms]
3 pass
0 fail
Ran 3 tests across 1 file. [1081.00ms]
```
To run all tests as concurrent, pass the `--concurrent` flag when
running tests.
Limitations:
- concurrent tests cannot attribute `expect()` call counts to the test,
meaning `expect.assertions()` does not function
- concurrent tests cannot use `toMatchSnapshot`. `toMatchInlineSnapshot`
is still supported.
- `beforeAll`/`afterAll` will never be executed concurrently.
`beforeEach`/`afterEach` will.
## Chaining
Chaining multiple describe/test qualifiers is now allowed. Previously,
it would fail.
```ts
// chaining-test-qualifiers.test.ts
test.failing.each([1, 2, 3])("each %i", async i => {
throw new Error(i);
});
```
```
$> bun-after test chaining-test-qualifiers
a.test.js:
✓ each 1
✓ each 2
✓ each 3
```
# Breaking changes:
## Describe ordering
Previously, describe callbacks were called immediately. Now, they are
deferred until the outer callback has finished running. The previous
order matched Jest. The new order is similar to Vitest, but does not
match exactly.
```ts
// describe-ordering.test.ts
describe("outer", () => {
console.log("outer before");
describe("inner", () => {
console.log("inner");
});
console.log("outer after");
});
```
Before, this would print
```
$> bun-before test describe-ordering
outer before
inner
outer after
```
Now, this will print
```
$> bun-after test describe-ordering
outer before
outer after
inner
```
## Test ordering
Describes are no longer always called before tests. They are now in
order.
```ts
// test-ordering.test.ts
test("one", () => {});
describe("scope", () => {
test("two", () => {});
});
test("three", () => {});
```
Before, this would print
```
$> bun-before test test-ordering
✓ scope > two
✓ one
✓ three
```
Now, this will print
```
$> bun-after test test-ordering
✓ one
✓ scope > two
✓ three
```
## Preload hooks
Previously, beforeAll in a preload ran before the first file and
afterAll ran after the last file. Now, beforeAll will run at the start
of each file and afterAll will run at the end of each file. This
behaviour matches Jest and Vitest.
```ts
// preload.ts
beforeAll(() => console.log("preload: beforeAll"));
afterAll(() => console.log("preload: afterAll"));
```
```ts
// preload-ordering-1.test.ts
test("demonstration file 1", () => {});
```
```ts
// preload-ordering-2.test.ts
test("demonstration file 2", () => {});
```
```
$> bun-before test --preload=./preload preload-ordering
preload-ordering-1.test.ts:
preload: beforeAll
✓ demonstration file 1
preload-ordering-2.test.ts:
✓ demonstration file 2
preload: afterAll
```
```
$> bun-after test --preload=./preload preload-ordering
preload-ordering-1.test.ts:
preload: beforeAll
✓ demonstration file 1
preload: afterAll
preload-ordering-2.test.ts:
preload: beforeAll
✓ demonstration file 2
preload: afterAll
```
## Describe failures
Current behaviour is that when an error is thrown inside a describe
callback, none of the tests declared there will run. Now, describes
declared inside will also not run. The new behaviour matches the
behaviour of Jest and Vitest.
```ts
// describe-failures.test.ts
describe("erroring describe", () => {
test("this test does not run because its describe failed", () => {
expect(true).toBe(true);
});
describe("inner describe", () => {
console.log("does the inner describe callback get called?");
test("does the inner test run?", () => {
expect(true).toBe(true);
});
});
throw new Error("uh oh!");
});
```
Before, the inner describe callback would be called and the inner test
would run, although the outer test would not:
```
$> bun-before test describe-failures
describe-failures.test.ts:
does the inner describe callback get called?
# Unhandled error between tests
-------------------------------
11 | throw new Error("uh oh!");
^
error: uh oh!
-------------------------------
✓ erroring describe > inner describe > does the inner test run?
1 pass
0 fail
1 error
1 expect() calls
Ran 1 test across 1 file.
Exited with code [1]
```
Now, the inner describe callback is not called at all.
```
$> bun-after test describe-failures
describe-failures.test.ts:
# Unhandled error between tests
-------------------------------
11 | throw new Error("uh oh!");
^
error: uh oh!
-------------------------------
0 pass
0 fail
1 error
Ran 0 tests across 1 file.
Exited with code [1]
```
## Hook failures
Previously, a beforeAll failure would skip subsequent beforeAll()s, the
test, and the afterAll. Now, a beforeAll failure skips any subsequent
beforeAll()s and the test, but not the afterAll.
```js
beforeAll(() => {
throw new Error("before all: uh oh!");
});
test("my test", () => {
console.log("my test");
});
afterAll(() => console.log("after all"));
```
```
$> bun-before test hook-failures
Error: before all: uh oh!
$> bun-after test hook-failures
Error: before all: uh oh!
after all
```
Previously, an async beforeEach failure would still allow the test to
run. Now, an async beforeEach failure will prevent the test from running
```js
beforeEach(() => {
await 0;
throw "uh oh!";
});
it("the test", async () => {
console.log("does the test run?");
});
```
```
$> bun-before test async-beforeeach-failure
does the test run?
error: uh oh!
uh oh!
✗ the test
$> bun-after test async-beforeeach-failure
error: uh oh!
uh oh!
✗ the test
```
## Hook timeouts
Hooks will now time out, and can have their timeout configured in an
options parameter
```js
beforeAll(async () => {
await Bun.sleep(1000);
}, 500);
test("my test", () => {
console.log("ran my test");
});
```
```
$> bun-before test hook-timeouts
ran my test
Ran 1 test across 1 file. [1011.00ms]
$> bun-after test hook-timeouts
✗ my test [501.15ms]
^ a beforeEach/afterEach hook timed out for this test.
```
## Hook execution order
beforeAll will now execute before the tests in the scope, rather than
immediately when it is called.
```ts
describe("d1", () => {
beforeAll(() => {
console.log("<d1>");
});
test("test", () => {
console.log(" test");
});
afterAll(() => {
console.log("</d1>");
});
});
describe("d2", () => {
beforeAll(() => {
console.log("<d2>");
});
test("test", () => {
console.log(" test");
});
afterAll(() => {
console.log("</d2>");
});
});
```
```
$> bun-before test ./beforeall-ordering.test.ts
<d1>
<d2>
test
</d1>
test
</d2>
$> bun-after test ./beforeall-ordering.test.ts
<d1>
test
</d1>
<d2>
test
</d2>
```
## test inside test
test() inside test() now errors rather than silently failing. Support
for this may be added in the future.
```ts
test("outer", () => {
console.log("outer");
test("inner", () => {
console.log("inner");
});
});
```
```
$> bun-before test
outer
✓ outer [0.06ms]
1 pass
0 fail
Ran 1 test across 1 file. [8.00ms]
$> bun-after test
outer
1 | test("outer", () => {
2 | console.log("outer");
3 | test("inner", () => {
^
error: Cannot call test() inside a test. Call it inside describe() instead.
✗ outer [0.71ms]
0 pass
1 fail
```
## afterAll inside test
afterAll inside a test is no longer allowed
```ts
test("test 1", () => {
afterAll(() => console.log("afterAll"));
console.log("test 1");
});
test("test 2", () => {
console.log("test 2");
});
```
```
$> bun-before
test 1
✓ test 1 [0.05ms]
test 2
✓ test 2
afterAll
$> bun-after
error: Cannot call afterAll() inside a test. Call it inside describe() instead.
✗ test 1 [1.00ms]
test 2
✓ test 2 [0.20ms]
```
# Only inside only
Previously, an outer 'describe.only' would run all tests inside it even
if there was an inner 'test.only'. Now, only the innermost only tests
are executed.
```ts
describe.only("outer", () => {
test("one", () => console.log("should not run"));
test.only("two", () => console.log("should run"));
});
```
```
$> bun-before test
should not run
should run
$> bun-after test
should run
```
With no inner only, the outer only will still run all tests:
```ts
describe.only("outer", () => {
test("test 1", () => console.log("test 1 runs"));
test("test 2", () => console.log("test 2 runs"));
});
```
# Potential follow-up work
- [ ] for concurrent tests, display headers before console.log messages
saying which test it is for
- this will need async context or similar
- refActiveExecutionEntry should also be able to know the current test
even in test.concurrent
- [ ] `test("rerun me", () => { console.log("run one time!"); });`
`--rerun-each=3` <- this runs the first and third time but not the
second time. fix.
- [ ] should to cache the JSValue created from
DoneCallback.callAsFunction
- [ ] implement retry and rerun params for tests.
- [ ] Remove finalizer on ScopeFunctions.zig by storing the data in 3
jsvalues passed in bind rather than using a custom class. We should also
migrate off of the ClassGenerator for ScopeFunctions
- [ ] support concurrent limit, how many concurrent tests are allowed to
run at a time. ie `--concurrent-limit=25`
- [ ] flag to run tests in random order
- [ ] `test.failing` should have its own style in the same way
`test.todo` passing marks as 'todo' insetead of 'passing'. right now
it's `✓` which is confusing.
- [ ] remove all instances of bun.jsc.Jest.Jest.current
- [ ] test options should be in BunTestRoot
- [ ] we will need one global still, stored in the globalobject/vm/?.
but it should not be a Jest instance.
- [ ] consider allowing test() inside test(), as well as afterEach and
afterAll. could even allow describe() too. to do this we would switch
from indices to pointers and they would be in a linked list. they would
be allocated in memorypools for perf/locality. some special
consideration is needed for making sure repeated tests lose their
temporary items. this could also improve memory usage soomewhat.
- [ ] consider using a jsc Bound Function rather than CallbackWithArgs.
bound functions allow adding arguments and they are only one value for
GC instead of many. and this removes our unnecessary three copies.
- [ ] eliminate Strong.Safe. we should be using a C++ class instead.
- [ ] consider modifying the junit reporter to print the whole describe
tree at the end instead of trying to output as test results come in. and
move it into its own file.
- [ ] expect_call_count/expect_assertions is confusing. rename to
`expect_calls`, `assert_expect_calls`. or something.
- [ ] Should make line_no be an enum with a none option and a function
to get if line nombers are enabled
- [ ] looks like we don't need to use file_id anymore (remove
`bun.jsc.Jest.Jest.runner.?.getOrPutFile(file_path).file_id;`, store the
file path directly)
- [ ] 'dot' test reporter like vitest?
- [ ] `test.failing.if(false)` errors because it can't replace mode
'failing' with mode 'skip'. this should probably be allowed instead.
- [ ] trigger timeout termination exception for `while(true) {}`
- [ ] clean up unused callbacks. as soon as we advance to the next
execution group, we can fully clean out the previous one. sometimes
within an execution sequence we can do the same.
- clean by swapping held values with undefined
- [ ] structure cache for performance for donecallback/scopefunctions
- [ ] consider migrating CallbackWithArgs to be a bound function. the
length of the bound function can exclude the specified args.
- [ ] setting both result and maybe_skip is not ideal, maybe there
should be a function to do both at once?
- [ ] try using a linked list rather than arraylist for describe/test
children, see how it affects performance
- [ ] consider a memory pool for describescope/executionentry. test if
it improves performance.
- [ ] consider making RefDataValue methods return the reason for failure
rather than ?value. that way we can improve error messages. the reason
could be a string or it could be a defined error set
- [ ] instead of 'description orelse (unnamed)', let's have description
default to 'unnamed' and not free it if it === the global that defines
that
- [ ] Add a phase before ordering results that inherits properties to
the parents. (eg inherit only from the child and inherit has_callback
from the child. and has_callback can be on describe/test individually
rather than on base). then we won't have that happening in an init()
function (terrible!)
- [ ] this test was incidentally passing because resolves.pass() wasn't
waiting for promise
```
test("fetching with Request object - issue #1527", async () => {
const server = createServer((req, res) => {
res.end();
}).listen(0);
try {
await once(server, "listening");
const body = JSON.stringify({ foo: "bar" });
const request = new Request(`http://localhost:${server.address().port}`,
{
method: "POST",
body,
});
expect(fetch(request)).resolves.pass();
} finally {
server.closeAllConnections();
}
});
```
- [ ] the error "expect.assertions() is not supported in the describe
phase, in concurrent tests, between tests, or after test execution has
completed" is not very good. we should be able to identify which of
those it is and print the right error for the context
- [ ] consider: instead of storing weak pointers to BunTest, we can
instead give the instance an id and check that it is correct when
getting the current bun test instance from the ref
- [ ] auto_killer: add three layers of auto_killer:
- preload (includes file & test)
- file (includes test)
- test
- that way at the end of the test, we kill the test processes. at the
end of the file, we kill the file processes. at the end of all, we kill
anything remaining.
AsyncLocalStorage
- store active_id & refdatavalue. active_id is a replacement for the
above weak pointers thing. refdatavalue is for determining which test it
is. this probably fits in 2×u64
- use for auto_killer so timeouts can kill even in concurrent tests
---------
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
tests not in `test/no-validate-leaksan.txt` will run with leaksanitizer
in CI
leaks documented in `test/leaksan.supp` will not cause a test failure
-- notes about leaksanitizer
- will not catch garbage collected objects accumulated during
long-running processes
- will not catch js objects (eg a strong held to a promise)
- will catch native calls to `malloc` not `free`d
- will catch allocations made in C, Zig, C++, libc, dependencies,
dlopen'd
---------
Co-authored-by: Jarred Sumner <jarred@jarredsumner.com>
* Define a generic allocator interface to enable static polymorphism for
allocators (see `GenericAllocator` in `src/allocators.zig`). Note that
`std.mem.Allocator` itself is considered a generic allocator.
* Add utilities to `bun.allocators` for working with generic allocators.
* Add a new namespace, `bun.memory`, with basic utilities for working
with memory and objects (`create`, `destroy`, `initDefault`, `deinit`).
* Add `bun.DefaultAllocator`, a zero-sized generic allocator type whose
`allocator` method simply returns `bun.default_allocator`.
* Implement the generic allocator interface in `AllocationScope` and
`MimallocArena`.
* Improve `bun.threading.GuardedValue` (now `bun.threading.Guarded`).
* Improve `bun.safety.AllocPtr` (now `bun.safety.CheckedAllocator`).
(For internal tracking: fixes STAB-1085, STAB-1086, STAB-1087,
STAB-1088, STAB-1089, STAB-1090, STAB-1091)
Replace `catch bun.outOfMemory()`, which can accidentally catch
non-OOM-related errors, with either `bun.handleOom` or a manual `catch
|err| switch (err)`.
(For internal tracking: fixes STAB-1070)
---------
Co-authored-by: Dylan Conway <dylan.conway567@gmail.com>
* `IncrementalGraph(.client).File` packs its fields in a specific way to
save space, but it makes the struct hard to use and error-prone (e.g.,
untagged unions with tags stored in a separate `flags` struct). This PR
changes `File` to have a human-readable layout, but adds methods to
convert it to and from `File.Packed`, a packed version with the same
space efficiency as before.
* Reduce the need to pass the dev allocator to functions (e.g.,
`deinit`) by storing it as a struct field via the new `DevAllocator`
type. This type has no overhead in release builds, or when
`AllocationScope` is disabled.
* Use owned pointers in `PackedMap`.
* Use `bun.ptr.Shared` for `PackedMap` instead of the old
`bun.ptr.RefPtr`.
* Add `bun.ptr.ScopedOwned`, which is like `bun.ptr.Owned`, but can
store an `AllocationScope`. No overhead in release builds or when
`AllocationScope` is disabled.
* Reduce redundant allocators in `BundleV2`.
* Add owned pointer conversions to `MutableString`.
* Make `AllocationScope` behave like a pointer, so it can be moved
without invalidating allocations. This eliminates the need for
self-references.
* Change memory cost algorithm so it doesn't rely on “dedupe bits”.
These bits used to take advantage of padding but there is now no padding
in `PackedMap`.
* Replace `VoidFieldTypes` with `useAllFields`; this eliminates the need
for `voidFieldTypesDiscardHelper`.
(For internal tracking: fixes STAB-1035, STAB-1036, STAB-1037,
STAB-1038, STAB-1039, STAB-1040, STAB-1041, STAB-1042, STAB-1043,
STAB-1044, STAB-1045)
---------
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: Jarred Sumner <jarred@jarredsumner.com>
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude <noreply@anthropic.com>
We can't use `std.heap.c_allocator` as `z_allocator`; it doesn't
zero-initialize the memory. This PR adds a fallback implementation.
This PR also makes Bun compile successfully with `use_mimalloc` set to
false. More work is likely necessary to make it function correctly in
this case, but it should at least compile.
(For internal tracking: fixes STAB-978, STAB-979)
* Move `DebugThreadLock` to `bun.safety`
* Enable in `ci_assert` builds, but store stack traces only in debug
builds
* Reduce size of struct by making optional field non-optional
* Add `initLockedIfNonComptime` as a workaround for not being able to
call `initLocked` in comptime contexts
* Add `lockOrAssert` method to acquire the lock if unlocked, or else
assert that the current thread acquired the lock
* Add stack traces to `CriticalSection` and `AllocPtr` in debug builds
* Make `MimallocArena.init` infallible
* Make `MimallocArena.heap` non-nullable
* Rename `RefCount.active_counts` to `raw_count` and provide read-only
`get` method
* Add `bun.safety.alloc.assertEq` to assert that two allocators are
equal (avoiding comparison of undefined `ptr`s)
(For internal tracking: fixes STAB-917, STAB-918, STAB-962, STAB-963,
STAB-964, STAB-965)
---------
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
This slightly reduces memory use.
Maximum memory use of `bun test html-rewriter`, averaged across 100
iterations:
* 101975 kB without this change
* 101634 kB with this change
I also tried changing the code to always use the aligned allocation
functions, but this slightly increased memory use, to 102160 kB.
(For internal tracking: fixes ENG-19866)
Ensure we aren't using multiple allocators with the same list by storing
a pointer to the allocator in debug mode only.
This check is stricter than the bare minimum necessary to prevent
illegal behavior, so CI may reveal certain uses that fail the checks but
don't cause IB. Most of these cases should probably be updated to comply
with the new requirements—we want these types' invariants to be clear.
(For internal tracking: fixes ENG-14987)
