test --doc: allow import statements to be in a separate code block

[skybrian]

I'm trying out the new deno test --doc feature in the Deno 2 release candidate. It works, but might be nicer if I didn't have to write out imports in each code block.

Version: 2.0.0-rc.4

Example

Here is an import that will be needed in the following examples:

```ts
import { assertEquals } from "@std/assert";
```

Here's an example of how to use assertEquals:

```ts
assertEquals("hello".length, 5);
```

Here's a second example:

```ts
assertEquals([1, 2, 3], [1, 2, 3]);
```

What it does now:

Check file:///Users/skybrian/Projects/deno/repeat-test/docs/example.md$3-6.ts
Check file:///Users/skybrian/Projects/deno/repeat-test/docs/example.md$9-12.ts
Check file:///Users/skybrian/Projects/deno/repeat-test/docs/example.md$15-18.ts
error: TS2304 [ERROR]: Cannot find name 'assertEquals'.
    assertEquals([
    ~~~~~~~~~~~~
    at file:///Users/skybrian/Projects/deno/repeat-test/docs/example.md$15-18.ts:2:5

TS2304 [ERROR]: Cannot find name 'assertEquals'.
    assertEquals("hello".length, 5);
    ~~~~~~~~~~~~
    at file:///Users/skybrian/Projects/deno/repeat-test/docs/example.md$9-12.ts:2:5

Found 2 errors.

What I'd like it to do:

Don't report any errors, because the imports were declared in a previous code block.

How would it work?

I don't know what's best, but here are some alternatives:

• When there is a code block that only contains imports, automatically prepend it to each of the following code blocks.
• When there is a code block that has no imports, reuse the imports from the previous code block.

Or, perhaps both rules?

[iuioiua]

Why not just add the import statement to your code blocks?