# formatDiagnostic (/docs/api/functions/formatDiagnostic)



```ts
function formatDiagnostic(d, source?): string;
```

Defined in: [packages/core/src/diagnostics.ts:63](https://github.com/austenstone/actio/blob/2b01e694a0f76521d8c073f3c6a2e48917d2c9d9/packages/core/src/diagnostics.ts#L63)

## Parameters [#parameters]

### d [#d]

[`Diagnostic`](../interfaces/Diagnostic.mdx)

### source? [#source]

`string`

## Returns [#returns]

`string`


## Sitemap

Browse the full documentation: [Markdown sitemap](https://austenstone.github.io/actio/sitemap.md) · [XML sitemap](https://austenstone.github.io/actio/sitemap.xml)