mirror of
https://github.com/denoland/deno.git
synced 2024-12-17 21:03:01 -05:00
107 lines
2.7 KiB
Markdown
107 lines
2.7 KiB
Markdown
# Testing
|
|
|
|
Deno has a built-in test runner that you can use for testing JavaScript or
|
|
TypeScript code.
|
|
|
|
## Writing tests
|
|
|
|
To define a test you need to call `Deno.test` with a name and function to be
|
|
tested:
|
|
|
|
```ts
|
|
Deno.test("hello world", () => {
|
|
const x = 1 + 2;
|
|
if (x !== 3) {
|
|
throw Error("x should be equal to 3");
|
|
}
|
|
});
|
|
```
|
|
|
|
There are some useful assertion utilities at https://deno.land/std/testing to
|
|
make testing easier:
|
|
|
|
```ts
|
|
import { assertEquals } from "https://deno.land/std/testing/asserts.ts";
|
|
|
|
Deno.test("hello world", () => {
|
|
const x = 1 + 2;
|
|
assertEquals(x, 3);
|
|
});
|
|
```
|
|
|
|
### Async functions
|
|
|
|
You can also test asynchronous code by passing a test function that returns a
|
|
promise. For this you can use the `async` keyword when defining a function:
|
|
|
|
```ts
|
|
import { delay } from "https://deno.land/std/async/delay.ts";
|
|
|
|
Deno.test("async hello world", async () => {
|
|
const x = 1 + 2;
|
|
|
|
// await some async task
|
|
await delay(100);
|
|
|
|
if (x !== 3) {
|
|
throw Error("x should be equal to 3");
|
|
}
|
|
});
|
|
```
|
|
|
|
### Resource and async op sanitizers
|
|
|
|
Certain actions in Deno create resources in the resource table
|
|
([learn more here](./contributing/architecture.md)). These resources should be
|
|
closed after you are done using them.
|
|
|
|
For each test definition the test runner checks that all resources created in
|
|
this test have been closed. This is to prevent resource 'leaks'. This is enabled
|
|
by default for all tests, but can be disabled by setting the `sanitizeResources`
|
|
boolean to false in the test definition.
|
|
|
|
The same is true for async operation like interacting with the filesystem. The
|
|
test runner checks that each operation you start in the test is completed before
|
|
the end of the test. This is enabled by default for all tests, but can be
|
|
disabled by setting the `sanitizeOps` boolean to false in the test definition.
|
|
|
|
```ts
|
|
Deno.test({
|
|
name: "leaky test",
|
|
fn() {
|
|
Deno.open("hello.txt");
|
|
},
|
|
sanitizeResources: false,
|
|
sanitizeOps: false,
|
|
});
|
|
```
|
|
|
|
### Ignoring tests
|
|
|
|
Sometimes you want to ignore tests based on some sort of condition (for example
|
|
you only want a test to run on Windows). For this you can use the `ignore`
|
|
boolean in the test definition. If it is set to true the test will be skipped.
|
|
|
|
```ts
|
|
Deno.test({
|
|
name: "do macOS feature",
|
|
ignore: Deno.build.os !== "darwin",
|
|
fn() {
|
|
doMacOSFeature();
|
|
},
|
|
});
|
|
```
|
|
|
|
## Running tests
|
|
|
|
To run the test, call `deno test` with the file that contains your test
|
|
function:
|
|
|
|
```shell
|
|
deno test my_test.ts
|
|
```
|
|
|
|
You can also omit the file name, in which case all tests in the current
|
|
directory (recursively) that match the glob `{*_,*.,}test.{js,mjs,ts,jsx,tsx}`
|
|
will be run. If you pass a directory, all files in the directory that match this
|
|
glob will be run.
|