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docs: add deno check --check-js and deno fmt --fail-fast #2952

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thisisjofrank merged 1 commit into from
Mar 5, 2026
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docs: add deno check --check-js and deno fmt --fail-fast #2952

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14 changes: 12 additions & 2 deletions runtime/reference/cli/check.md
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Original file line number Diff line number Diff line change
Expand Up @@ -7,9 +7,9 @@ openGraphTitle: "deno check"
description: "Download and type-check code without execution"
---

## Example
## Examples

Type-check without execution.
Type-check a TypeScript file without execution:

```ts title="example.ts"
const x: string = 1 + 1n;
Expand All @@ -18,3 +18,13 @@ const x: string = 1 + 1n;
```bash
deno check example.ts
```

## Type-checking JavaScript files

If you have a JavaScript-only project and want to type-check it with Deno, you
can use the `--check-js` flag instead of adding `// @ts-check` to every file or
setting `compilerOptions.checkJs` in your `deno.json`:

```bash
deno check --check-js main.js
```
10 changes: 10 additions & 0 deletions runtime/reference/cli/fmt.md
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Expand Up @@ -57,6 +57,16 @@ enclosed in triple backticks and have a language attribute.

:::

## Checking formatting in CI

Use `--check` to verify files are formatted without modifying them. Add
`--fail-fast` to stop on the first unformatted file instead of reporting all of
them, which is useful in large codebases:

```sh
deno fmt --check --fail-fast
```

## Ignoring Code

### JavaScript / TypeScript / JSONC
Expand Down