# `Expresso.Check.Document`
[🔗](https://github.com/rellen/expresso/blob/main/lib/expresso/check/document.ex#L1)

The checks of `--check` that need no tool: they read the deck and its HTML

`Expresso.Check` runs these checks at each level. Each check returns a list
of problems and a list of notes. A problem makes the exit status 1. A note
tells of a choice that can be correct, such as an image with no `alt` text.

| Check | Kind | Finds |
| --- | --- | --- |
| `theme/1` | problem | Each role of a theme of 16 colors under its minimum of contrast |
| `theme/1` | note | Each variant of the theme that does not dim at the `dim_contrast` option |
| `size/1` | note | The size of the document, and its largest files |
| `slides/1` | note | An image with no `alt` text, a diagram with no `alt` text, a slide with only a hidden heading, and a slide with no `h1` |

# `result`

```elixir
@type result() :: %{problems: [String.t()], notes: [String.t()]}
```

The problems and the notes of a check

# `size`

```elixir
@spec size(String.t()) :: result()
```

Return a note with the size of the document, and with the size and the type of its largest files

A file is a data URI in a `src`, an `href` or an `xlink:href` attribute, or
in a `url()` of a style sheet, such as a font of the theme.
`Expresso.Assets` keeps one copy of each large file, so the note names each
file one time.

    iex> Expresso.Check.Document.size(String.duplicate("a", 2_500_000))
    %{problems: [], notes: ["The document is 2.4 MB."]}

# `slides`

```elixir
@spec slides(String.t()) :: result()
```

Return a note for each slide with a part that a screen reader reads differently

The function reads the present view of each slide in the HTML, and it gives
a note for:

  * an image with an empty `alt`. A screen reader skips such an image.
  * a diagram with no `alt` option. A screen reader reads the text of its SVG.
  * a slide with only a hidden heading. A screen reader reads the heading,
    but the slide shows no title.
  * a slide with no `h1`, from the option `sr_heading false`.

# `theme`

```elixir
@spec theme(Expresso.Deck.t()) :: result()
```

Return a problem for each role of the theme of the deck under its minimum of contrast

The problems are the warnings of `Expresso.ThemeVerifier.messages/1`. A
built-in theme has no problem. The notes are the warnings of
`Expresso.ThemeVerifier.dim_messages/2`: a deck that does not dim can be
correct, so they do not change the exit status.

---

*Consult [api-reference.md](api-reference.md) for complete listing*