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| -rw-r--r-- | src/configuration.rs | 1421 |
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diff --git a/src/configuration.rs b/src/configuration.rs new file mode 100644 index 0000000..3e8823d --- /dev/null +++ b/src/configuration.rs @@ -0,0 +1,1421 @@ +use crate::util::{ + line_ending::LineEnding, + mdx::{EsmParse as MdxEsmParse, ExpressionParse as MdxExpressionParse}, +}; +use alloc::{boxed::Box, fmt, string::String}; + +/// Control which constructs are enabled. +/// +/// Not all constructs can be configured. +/// Notably, blank lines and paragraphs cannot be turned off. +/// +/// ## Examples +/// +/// ``` +/// use markdown::Constructs; +/// # fn main() { +/// +/// // Use the default trait to get `CommonMark` constructs: +/// let commonmark = Constructs::default(); +/// +/// // To turn on all of GFM, use the `gfm` method: +/// let gfm = Constructs::gfm(); +/// +/// // Or, mix and match: +/// let custom = Constructs { +/// math_flow: true, +/// math_text: true, +/// ..Constructs::gfm() +/// }; +/// # } +/// ``` +#[allow(clippy::struct_excessive_bools)] +#[derive(Clone, Debug, Eq, PartialEq)] +pub struct Constructs { + /// Attention. + /// + /// ```markdown + /// > | a *b* c **d**. + /// ^^^ ^^^^^ + /// ``` + pub attention: bool, + /// Autolink. + /// + /// ```markdown + /// > | a <https://example.com> b <user@example.org>. + /// ^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^ + /// ``` + pub autolink: bool, + /// Block quote. + /// + /// ```markdown + /// > | > a + /// ^^^ + /// ``` + pub block_quote: bool, + /// Character escape. + /// + /// ```markdown + /// > | a \* b + /// ^^ + /// ``` + pub character_escape: bool, + /// Character reference. + /// + /// ```markdown + /// > | a & b + /// ^^^^^ + /// ``` + pub character_reference: bool, + /// Code (indented). + /// + /// ```markdown + /// > | a + /// ^^^^^ + /// ``` + pub code_indented: bool, + /// Code (fenced). + /// + /// ```markdown + /// > | ~~~js + /// ^^^^^ + /// > | console.log(1) + /// ^^^^^^^^^^^^^^ + /// > | ~~~ + /// ^^^ + /// ``` + pub code_fenced: bool, + /// Code (text). + /// + /// ```markdown + /// > | a `b` c + /// ^^^ + /// ``` + pub code_text: bool, + /// Definition. + /// + /// ```markdown + /// > | [a]: b "c" + /// ^^^^^^^^^^ + /// ``` + pub definition: bool, + /// Frontmatter. + /// + /// ````markdown + /// > | --- + /// ^^^ + /// > | title: Neptune + /// ^^^^^^^^^^^^^^ + /// > | --- + /// ^^^ + /// ```` + pub frontmatter: bool, + /// GFM: autolink literal. + /// + /// ```markdown + /// > | https://example.com + /// ^^^^^^^^^^^^^^^^^^^ + /// ``` + pub gfm_autolink_literal: bool, + /// GFM: footnote definition. + /// + /// ```markdown + /// > | [^a]: b + /// ^^^^^^^ + /// ``` + pub gfm_footnote_definition: bool, + /// GFM: footnote label start. + /// + /// ```markdown + /// > | a[^b] + /// ^^ + /// ``` + pub gfm_label_start_footnote: bool, + /// + /// ```markdown + /// > | a ~b~ c. + /// ^^^ + /// ``` + pub gfm_strikethrough: bool, + /// GFM: table. + /// + /// ```markdown + /// > | | a | + /// ^^^^^ + /// > | | - | + /// ^^^^^ + /// > | | b | + /// ^^^^^ + /// ``` + pub gfm_table: bool, + /// GFM: task list item. + /// + /// ```markdown + /// > | * [x] y. + /// ^^^ + /// ``` + pub gfm_task_list_item: bool, + /// Hard break (escape). + /// + /// ```markdown + /// > | a\ + /// ^ + /// | b + /// ``` + pub hard_break_escape: bool, + /// Hard break (trailing). + /// + /// ```markdown + /// > | a␠␠ + /// ^^ + /// | b + /// ``` + pub hard_break_trailing: bool, + /// Heading (atx). + /// + /// ```markdown + /// > | # a + /// ^^^ + /// ``` + pub heading_atx: bool, + /// Heading (setext). + /// + /// ```markdown + /// > | a + /// ^^ + /// > | == + /// ^^ + /// ``` + pub heading_setext: bool, + /// HTML (flow). + /// + /// ```markdown + /// > | <div> + /// ^^^^^ + /// ``` + pub html_flow: bool, + /// HTML (text). + /// + /// ```markdown + /// > | a <b> c + /// ^^^ + /// ``` + pub html_text: bool, + /// Label start (image). + /// + /// ```markdown + /// > | a  d + /// ^^ + /// ``` + pub label_start_image: bool, + /// Label start (link). + /// + /// ```markdown + /// > | a [b](c) d + /// ^ + /// ``` + pub label_start_link: bool, + /// Label end. + /// + /// ```markdown + /// > | a [b](c) d + /// ^^^^ + /// ``` + pub label_end: bool, + /// List items. + /// + /// ```markdown + /// > | * a + /// ^^^ + /// ``` + pub list_item: bool, + /// Math (flow). + /// + /// ```markdown + /// > | $$ + /// ^^ + /// > | \frac{1}{2} + /// ^^^^^^^^^^^ + /// > | $$ + /// ^^ + /// ``` + pub math_flow: bool, + /// Math (text). + /// + /// ```markdown + /// > | a $b$ c + /// ^^^ + /// ``` + pub math_text: bool, + /// MDX: ESM. + /// + /// ```markdown + /// > | import a from 'b' + /// ^^^^^^^^^^^^^^^^^ + /// ``` + /// + /// > 👉 **Note**: to support ESM, you *must* pass + /// > [`mdx_esm_parse`][MdxEsmParse] in [`ParseOptions`][] too. + /// > Otherwise, ESM is treated as normal markdown. + pub mdx_esm: bool, + /// MDX: expression (flow). + /// + /// ```markdown + /// > | {Math.PI} + /// ^^^^^^^^^ + /// ``` + /// + /// > 👉 **Note**: You *can* pass + /// > [`mdx_expression_parse`][MdxExpressionParse] in [`ParseOptions`][] + /// > too, to parse expressions according to a certain grammar (typically, + /// > a programming language). + /// > Otherwise, expressions are parsed with a basic algorithm that only + /// > cares about braces. + pub mdx_expression_flow: bool, + /// MDX: expression (text). + /// + /// ```markdown + /// > | a {Math.PI} c + /// ^^^^^^^^^ + /// ``` + /// + /// > 👉 **Note**: You *can* pass + /// > [`mdx_expression_parse`][MdxExpressionParse] in [`ParseOptions`][] + /// > too, to parse expressions according to a certain grammar (typically, + /// > a programming language). + /// > Otherwise, expressions are parsed with a basic algorithm that only + /// > cares about braces. + pub mdx_expression_text: bool, + /// MDX: JSX (flow). + /// + /// ```markdown + /// > | <Component /> + /// ^^^^^^^^^^^^^ + /// ``` + /// + /// > 👉 **Note**: You *must* pass `html_flow: false` to use this, + /// > as it’s preferred when on over `mdx_jsx_flow`. + /// + /// > 👉 **Note**: You *can* pass + /// > [`mdx_expression_parse`][MdxExpressionParse] in [`ParseOptions`][] + /// > too, to parse expressions in JSX according to a certain grammar + /// > (typically, a programming language). + /// > Otherwise, expressions are parsed with a basic algorithm that only + /// > cares about braces. + pub mdx_jsx_flow: bool, + /// MDX: JSX (text). + /// + /// ```markdown + /// > | a <Component /> c + /// ^^^^^^^^^^^^^ + /// ``` + /// + /// > 👉 **Note**: You *must* pass `html_text: false` to use this, + /// > as it’s preferred when on over `mdx_jsx_text`. + /// + /// > 👉 **Note**: You *can* pass + /// > [`mdx_expression_parse`][MdxExpressionParse] in [`ParseOptions`][] + /// > too, to parse expressions in JSX according to a certain grammar + /// > (typically, a programming language). + /// > Otherwise, expressions are parsed with a basic algorithm that only + /// > cares about braces. + pub mdx_jsx_text: bool, + /// Thematic break. + /// + /// ```markdown + /// > | *** + /// ^^^ + /// ``` + pub thematic_break: bool, +} + +impl Default for Constructs { + /// `CommonMark`. + /// + /// `CommonMark` is a relatively strong specification of how markdown + /// works. + /// Most markdown parsers try to follow it. + /// + /// For more information, see the `CommonMark` specification: + /// <https://spec.commonmark.org>. + fn default() -> Self { + Self { + attention: true, + autolink: true, + block_quote: true, + character_escape: true, + character_reference: true, + code_indented: true, + code_fenced: true, + code_text: true, + definition: true, + frontmatter: false, + gfm_autolink_literal: false, + gfm_label_start_footnote: false, + gfm_footnote_definition: false, + gfm_strikethrough: false, + gfm_table: false, + gfm_task_list_item: false, + hard_break_escape: true, + hard_break_trailing: true, + heading_atx: true, + heading_setext: true, + html_flow: true, + html_text: true, + label_start_image: true, + label_start_link: true, + label_end: true, + list_item: true, + math_flow: false, + math_text: false, + mdx_esm: false, + mdx_expression_flow: false, + mdx_expression_text: false, + mdx_jsx_flow: false, + mdx_jsx_text: false, + thematic_break: true, + } + } +} + +impl Constructs { + /// GFM. + /// + /// GFM stands for **GitHub flavored markdown**. + /// GFM extends `CommonMark` and adds support for autolink literals, + /// footnotes, strikethrough, tables, and tasklists. + /// + /// For more information, see the GFM specification: + /// <https://github.github.com/gfm/>. + pub fn gfm() -> Self { + Self { + gfm_autolink_literal: true, + gfm_footnote_definition: true, + gfm_label_start_footnote: true, + gfm_strikethrough: true, + gfm_table: true, + gfm_task_list_item: true, + ..Self::default() + } + } + + /// MDX. + /// + /// This turns on `CommonMark`, turns off some conflicting constructs + /// (autolinks, code (indented), and HTML), and turns on MDX (ESM, + /// expressions, and JSX). + /// + /// For more information, see the MDX website: + /// <https://mdxjs.com>. + /// + /// > 👉 **Note**: to support ESM, you *must* pass + /// > [`mdx_esm_parse`][MdxEsmParse] in [`ParseOptions`][] too. + /// > Otherwise, ESM is treated as normal markdown. + /// > + /// > You *can* pass + /// > [`mdx_expression_parse`][MdxExpressionParse] + /// > to parse expressions according to a certain grammar (typically, a + /// > programming language). + /// > Otherwise, expressions are parsed with a basic algorithm that only + /// > cares about braces. + pub fn mdx() -> Self { + Self { + autolink: false, + code_indented: false, + html_flow: false, + html_text: false, + mdx_esm: true, + mdx_expression_flow: true, + mdx_expression_text: true, + mdx_jsx_flow: true, + mdx_jsx_text: true, + ..Self::default() + } + } +} + +/// Configuration that describes how to compile to HTML. +/// +/// You likely either want to turn on the dangerous options +/// (`allow_dangerous_html`, `allow_dangerous_protocol`) when dealing with +/// input you trust, or want to customize how GFM footnotes are compiled +/// (typically because the input markdown is not in English). +/// +/// ## Examples +/// +/// ``` +/// use markdown::CompileOptions; +/// # fn main() { +/// +/// // Use the default trait to get safe defaults: +/// let safe = CompileOptions::default(); +/// +/// // Live dangerously / trust the author: +/// let danger = CompileOptions { +/// allow_dangerous_html: true, +/// allow_dangerous_protocol: true, +/// ..CompileOptions::default() +/// }; +/// +/// // In French: +/// let enFrançais = CompileOptions { +/// gfm_footnote_label: Some("Notes de bas de page".into()), +/// gfm_footnote_back_label: Some("Arrière".into()), +/// ..CompileOptions::default() +/// }; +/// # } +/// ``` +#[allow(clippy::struct_excessive_bools)] +#[derive(Clone, Debug, Default)] +pub struct CompileOptions { + /// Whether to allow (dangerous) HTML. + /// + /// The default is `false`, which still parses the HTML according to + /// `CommonMark` but shows the HTML as text instead of as elements. + /// + /// Pass `true` for trusted content to get actual HTML elements. + /// + /// ## Examples + /// + /// ``` + /// use markdown::{to_html, to_html_with_options, CompileOptions, Options}; + /// # fn main() -> Result<(), String> { + /// + /// // `markdown-rs` is safe by default: + /// assert_eq!( + /// to_html("Hi, <i>venus</i>!"), + /// "<p>Hi, <i>venus</i>!</p>" + /// ); + /// + /// // Turn `allow_dangerous_html` on to allow potentially dangerous HTML: + /// assert_eq!( + /// to_html_with_options( + /// "Hi, <i>venus</i>!", + /// &Options { + /// compile: CompileOptions { + /// allow_dangerous_html: true, + /// ..CompileOptions::default() + /// }, + /// ..Options::default() + /// } + /// )?, + /// "<p>Hi, <i>venus</i>!</p>" + /// ); + /// # Ok(()) + /// # } + /// ``` + pub allow_dangerous_html: bool, + + /// Whether to allow dangerous protocols in links and images. + /// + /// The default is `false`, which drops URLs in links and images that use + /// dangerous protocols. + /// + /// Pass `true` for trusted content to support all protocols. + /// + /// URLs that have no protocol (which means it’s relative to the current + /// page, such as `./some/page.html`) and URLs that have a safe protocol + /// (for images: `http`, `https`; for links: `http`, `https`, `irc`, + /// `ircs`, `mailto`, `xmpp`), are safe. + /// All other URLs are dangerous and dropped. + /// + /// ## Examples + /// + /// ``` + /// use markdown::{to_html, to_html_with_options, CompileOptions, Options}; + /// # fn main() -> Result<(), String> { + /// + /// // `markdown-rs` is safe by default: + /// assert_eq!( + /// to_html("<javascript:alert(1)>"), + /// "<p><a href=\"\">javascript:alert(1)</a></p>" + /// ); + /// + /// // Turn `allow_dangerous_protocol` on to allow potentially dangerous protocols: + /// assert_eq!( + /// to_html_with_options( + /// "<javascript:alert(1)>", + /// &Options { + /// compile: CompileOptions { + /// allow_dangerous_protocol: true, + /// ..CompileOptions::default() + /// }, + /// ..Options::default() + /// } + /// )?, + /// "<p><a href=\"javascript:alert(1)\">javascript:alert(1)</a></p>" + /// ); + /// # Ok(()) + /// # } + /// ``` + pub allow_dangerous_protocol: bool, + + /// Default line ending to use when compiling to HTML, for line endings not + /// in `value`. + /// + /// Generally, `markdown-rs` copies line endings (`\r`, `\n`, `\r\n`) in + /// the markdown document over to the compiled HTML. + /// In some cases, such as `> a`, CommonMark requires that extra line + /// endings are added: `<blockquote>\n<p>a</p>\n</blockquote>`. + /// + /// To create that line ending, the document is checked for the first line + /// ending that is used. + /// If there is no line ending, `default_line_ending` is used. + /// If that isn’t configured, `\n` is used. + /// + /// ## Examples + /// + /// ``` + /// use markdown::{to_html, to_html_with_options, CompileOptions, LineEnding, Options}; + /// # fn main() -> Result<(), String> { + /// + /// // `markdown-rs` uses `\n` by default: + /// assert_eq!( + /// to_html("> a"), + /// "<blockquote>\n<p>a</p>\n</blockquote>" + /// ); + /// + /// // Define `default_line_ending` to configure the default: + /// assert_eq!( + /// to_html_with_options( + /// "> a", + /// &Options { + /// compile: CompileOptions { + /// default_line_ending: LineEnding::CarriageReturnLineFeed, + /// ..CompileOptions::default() + /// }, + /// ..Options::default() + /// } + /// )?, + /// "<blockquote>\r\n<p>a</p>\r\n</blockquote>" + /// ); + /// # Ok(()) + /// # } + /// ``` + pub default_line_ending: LineEnding, + + /// Textual label to use for the footnotes section. + /// + /// The default value is `"Footnotes"`. + /// Change it when the markdown is not in English. + /// + /// This label is typically hidden visually (assuming a `sr-only` CSS class + /// is defined that does that), and thus affects screen readers only. + /// If you do have such a class, but want to show this section to everyone, + /// pass different attributes with the `gfm_footnote_label_attributes` + /// option. + /// + /// ## Examples + /// + /// ``` + /// use markdown::{to_html_with_options, CompileOptions, Options, ParseOptions}; + /// # fn main() -> Result<(), String> { + /// + /// // `"Footnotes"` is used by default: + /// assert_eq!( + /// to_html_with_options( + /// "[^a]\n\n[^a]: b", + /// &Options::gfm() + /// )?, + /// "<p><sup><a href=\"#user-content-fn-a\" id=\"user-content-fnref-a\" data-footnote-ref=\"\" aria-describedby=\"footnote-label\">1</a></sup></p>\n<section data-footnotes=\"\" class=\"footnotes\"><h2 id=\"footnote-label\" class=\"sr-only\">Footnotes</h2>\n<ol>\n<li id=\"user-content-fn-a\">\n<p>b <a href=\"#user-content-fnref-a\" data-footnote-backref=\"\" aria-label=\"Back to content\" class=\"data-footnote-backref\">↩</a></p>\n</li>\n</ol>\n</section>\n" + /// ); + /// + /// // Pass `gfm_footnote_label` to use something else: + /// assert_eq!( + /// to_html_with_options( + /// "[^a]\n\n[^a]: b", + /// &Options { + /// parse: ParseOptions::gfm(), + /// compile: CompileOptions { + /// gfm_footnote_label: Some("Notes de bas de page".into()), + /// ..CompileOptions::gfm() + /// } + /// } + /// )?, + /// "<p><sup><a href=\"#user-content-fn-a\" id=\"user-content-fnref-a\" data-footnote-ref=\"\" aria-describedby=\"footnote-label\">1</a></sup></p>\n<section data-footnotes=\"\" class=\"footnotes\"><h2 id=\"footnote-label\" class=\"sr-only\">Notes de bas de page</h2>\n<ol>\n<li id=\"user-content-fn-a\">\n<p>b <a href=\"#user-content-fnref-a\" data-footnote-backref=\"\" aria-label=\"Back to content\" class=\"data-footnote-backref\">↩</a></p>\n</li>\n</ol>\n</section>\n" + /// ); + /// # Ok(()) + /// # } + /// ``` + pub gfm_footnote_label: Option<String>, + + /// HTML tag name to use for the footnote label element. + /// + /// The default value is `"h2"`. + /// Change it to match your document structure. + /// + /// This label is typically hidden visually (assuming a `sr-only` CSS class + /// is defined that does that), and thus affects screen readers only. + /// If you do have such a class, but want to show this section to everyone, + /// pass different attributes with the `gfm_footnote_label_attributes` + /// option. + /// + /// ## Examples + /// + /// ``` + /// use markdown::{to_html_with_options, CompileOptions, Options, ParseOptions}; + /// # fn main() -> Result<(), String> { + /// + /// // `"h2"` is used by default: + /// assert_eq!( + /// to_html_with_options( + /// "[^a]\n\n[^a]: b", + /// &Options::gfm() + /// )?, + /// "<p><sup><a href=\"#user-content-fn-a\" id=\"user-content-fnref-a\" data-footnote-ref=\"\" aria-describedby=\"footnote-label\">1</a></sup></p>\n<section data-footnotes=\"\" class=\"footnotes\"><h2 id=\"footnote-label\" class=\"sr-only\">Footnotes</h2>\n<ol>\n<li id=\"user-content-fn-a\">\n<p>b <a href=\"#user-content-fnref-a\" data-footnote-backref=\"\" aria-label=\"Back to content\" class=\"data-footnote-backref\">↩</a></p>\n</li>\n</ol>\n</section>\n" + /// ); + /// + /// // Pass `gfm_footnote_label_tag_name` to use something else: + /// assert_eq!( + /// to_html_with_options( + /// "[^a]\n\n[^a]: b", + /// &Options { + /// parse: ParseOptions::gfm(), + /// compile: CompileOptions { + /// gfm_footnote_label_tag_name: Some("h1".into()), + /// ..CompileOptions::gfm() + /// } + /// } + /// )?, + /// "<p><sup><a href=\"#user-content-fn-a\" id=\"user-content-fnref-a\" data-footnote-ref=\"\" aria-describedby=\"footnote-label\">1</a></sup></p>\n<section data-footnotes=\"\" class=\"footnotes\"><h1 id=\"footnote-label\" class=\"sr-only\">Footnotes</h1>\n<ol>\n<li id=\"user-content-fn-a\">\n<p>b <a href=\"#user-content-fnref-a\" data-footnote-backref=\"\" aria-label=\"Back to content\" class=\"data-footnote-backref\">↩</a></p>\n</li>\n</ol>\n</section>\n" + /// ); + /// # Ok(()) + /// # } + /// ``` + pub gfm_footnote_label_tag_name: Option<String>, + + /// Attributes to use on the footnote label. + /// + /// The default value is `"class=\"sr-only\""`. + /// Change it to show the label and add other attributes. + /// + /// This label is typically hidden visually (assuming a `sr-only` CSS class + /// is defined that does that), and thus affects screen readers only. + /// If you do have such a class, but want to show this section to everyone, + /// pass an empty string. + /// You can also add different attributes. + /// + /// > 👉 **Note**: `id="footnote-label"` is always added, because footnote + /// > calls use it with `aria-describedby` to provide an accessible label. + /// + /// ## Examples + /// + /// ``` + /// use markdown::{to_html_with_options, CompileOptions, Options, ParseOptions}; + /// # fn main() -> Result<(), String> { + /// + /// // `"class=\"sr-only\""` is used by default: + /// assert_eq!( + /// to_html_with_options( + /// "[^a]\n\n[^a]: b", + /// &Options::gfm() + /// )?, + /// "<p><sup><a href=\"#user-content-fn-a\" id=\"user-content-fnref-a\" data-footnote-ref=\"\" aria-describedby=\"footnote-label\">1</a></sup></p>\n<section data-footnotes=\"\" class=\"footnotes\"><h2 id=\"footnote-label\" class=\"sr-only\">Footnotes</h2>\n<ol>\n<li id=\"user-content-fn-a\">\n<p>b <a href=\"#user-content-fnref-a\" data-footnote-backref=\"\" aria-label=\"Back to content\" class=\"data-footnote-backref\">↩</a></p>\n</li>\n</ol>\n</section>\n" + /// ); + /// + /// // Pass `gfm_footnote_label_attributes` to use something else: + /// assert_eq!( + /// to_html_with_options( + /// "[^a]\n\n[^a]: b", + /// &Options { + /// parse: ParseOptions::gfm(), + /// compile: CompileOptions { + /// gfm_footnote_label_attributes: Some("class=\"footnote-heading\"".into()), + /// ..CompileOptions::gfm() + /// } + /// } + /// )?, + /// "<p><sup><a href=\"#user-content-fn-a\" id=\"user-content-fnref-a\" data-footnote-ref=\"\" aria-describedby=\"footnote-label\">1</a></sup></p>\n<section data-footnotes=\"\" class=\"footnotes\"><h2 id=\"footnote-label\" class=\"footnote-heading\">Footnotes</h2>\n<ol>\n<li id=\"user-content-fn-a\">\n<p>b <a href=\"#user-content-fnref-a\" data-footnote-backref=\"\" aria-label=\"Back to content\" class=\"data-footnote-backref\">↩</a></p>\n</li>\n</ol>\n</section>\n" + /// ); + /// # Ok(()) + /// # } + /// ``` + pub gfm_footnote_label_attributes: Option<String>, + + /// Textual label to describe the backreference back to footnote calls. + /// + /// The default value is `"Back to content"`. + /// Change it when the markdown is not in English. + /// + /// This label is used in the `aria-label` attribute on each backreference + /// (the `↩` links). + /// It affects users of assistive technology. + /// + /// ## Examples + /// + /// ``` + /// use markdown::{to_html_with_options, CompileOptions, Options, ParseOptions}; + /// # fn main() -> Result<(), String> { + /// + /// // `"Back to content"` is used by default: + /// assert_eq!( + /// to_html_with_options( + /// "[^a]\n\n[^a]: b", + /// &Options::gfm() + /// )?, + /// "<p><sup><a href=\"#user-content-fn-a\" id=\"user-content-fnref-a\" data-footnote-ref=\"\" aria-describedby=\"footnote-label\">1</a></sup></p>\n<section data-footnotes=\"\" class=\"footnotes\"><h2 id=\"footnote-label\" class=\"sr-only\">Footnotes</h2>\n<ol>\n<li id=\"user-content-fn-a\">\n<p>b <a href=\"#user-content-fnref-a\" data-footnote-backref=\"\" aria-label=\"Back to content\" class=\"data-footnote-backref\">↩</a></p>\n</li>\n</ol>\n</section>\n" + /// ); + /// + /// // Pass `gfm_footnote_back_label` to use something else: + /// assert_eq!( + /// to_html_with_options( + /// "[^a]\n\n[^a]: b", + /// &Options { + /// parse: ParseOptions::gfm(), + /// compile: CompileOptions { + /// gfm_footnote_back_label: Some("Arrière".into()), + /// ..CompileOptions::gfm() + /// } + /// } + /// )?, + /// "<p><sup><a href=\"#user-content-fn-a\" id=\"user-content-fnref-a\" data-footnote-ref=\"\" aria-describedby=\"footnote-label\">1</a></sup></p>\n<section data-footnotes=\"\" class=\"footnotes\"><h2 id=\"footnote-label\" class=\"sr-only\">Footnotes</h2>\n<ol>\n<li id=\"user-content-fn-a\">\n<p>b <a href=\"#user-content-fnref-a\" data-footnote-backref=\"\" aria-label=\"Arrière\" class=\"data-footnote-backref\">↩</a></p>\n</li>\n</ol>\n</section>\n" + /// ); + /// # Ok(()) + /// # } + /// ``` + pub gfm_footnote_back_label: Option<String>, + + /// Prefix to use before the `id` attribute on footnotes to prevent them + /// from *clobbering*. + /// + /// The default is `"user-content-"`. + /// Pass `Some("".into())` for trusted markdown and when you are careful + /// with polyfilling. + /// You could pass a different prefix. + /// + /// DOM clobbering is this: + /// + /// ```html + /// <p id="x"></p> + /// <script>alert(x) // `x` now refers to the `p#x` DOM element</script> + /// ``` + /// + /// The above example shows that elements are made available by browsers, + /// by their ID, on the `window` object. + /// This is a security risk because you might be expecting some other + /// variable at that place. + /// It can also break polyfills. + /// Using a prefix solves these problems. + /// + /// ## Examples + /// + /// ``` + /// use markdown::{to_html_with_options, CompileOptions, Options, ParseOptions}; + /// # fn main() -> Result<(), String> { + /// + /// // `"user-content-"` is used by default: + /// assert_eq!( + /// to_html_with_options( + /// "[^a]\n\n[^a]: b", + /// &Options::gfm() + /// )?, + /// "<p><sup><a href=\"#user-content-fn-a\" id=\"user-content-fnref-a\" data-footnote-ref=\"\" aria-describedby=\"footnote-label\">1</a></sup></p>\n<section data-footnotes=\"\" class=\"footnotes\"><h2 id=\"footnote-label\" class=\"sr-only\">Footnotes</h2>\n<ol>\n<li id=\"user-content-fn-a\">\n<p>b <a href=\"#user-content-fnref-a\" data-footnote-backref=\"\" aria-label=\"Back to content\" class=\"data-footnote-backref\">↩</a></p>\n</li>\n</ol>\n</section>\n" + /// ); + /// + /// // Pass `gfm_footnote_clobber_prefix` to use something else: + /// assert_eq!( + /// to_html_with_options( + /// "[^a]\n\n[^a]: b", + /// &Options { + /// parse: ParseOptions::gfm(), + /// compile: CompileOptions { + /// gfm_footnote_clobber_prefix: Some("".into()), + /// ..CompileOptions::gfm() + /// } + /// } + /// )?, + /// "<p><sup><a href=\"#fn-a\" id=\"fnref-a\" data-footnote-ref=\"\" aria-describedby=\"footnote-label\">1</a></sup></p>\n<section data-footnotes=\"\" class=\"footnotes\"><h2 id=\"footnote-label\" class=\"sr-only\">Footnotes</h2>\n<ol>\n<li id=\"fn-a\">\n<p>b <a href=\"#fnref-a\" data-footnote-backref=\"\" aria-label=\"Back to content\" class=\"data-footnote-backref\">↩</a></p>\n</li>\n</ol>\n</section>\n" + /// ); + /// # Ok(()) + /// # } + /// ``` + pub gfm_footnote_clobber_prefix: Option<String>, + + /// Whether to support the GFM tagfilter. + /// + /// This option does nothing if `allow_dangerous_html` is not turned on. + /// The default is `false`, which does not apply the GFM tagfilter to HTML. + /// Pass `true` for output that is a bit closer to GitHub’s actual output. + /// + /// The tagfilter is kinda weird and kinda useless. + /// The tag filter is a naïve attempt at XSS protection. + /// You should use a proper HTML sanitizing algorithm instead. + /// + /// ## Examples + /// + /// ``` + /// use markdown::{to_html_with_options, CompileOptions, Options, ParseOptions}; + /// # fn main() -> Result<(), String> { + /// + /// // With `allow_dangerous_html`, `markdown-rs` passes HTML through untouched: + /// assert_eq!( + /// to_html_with_options( + /// "<iframe>", + /// &Options { + /// parse: ParseOptions::gfm(), + /// compile: CompileOptions { + /// allow_dangerous_html: true, + /// ..CompileOptions::default() + /// } + /// } + /// )?, + /// "<iframe>" + /// ); + /// + /// // Pass `gfm_tagfilter: true` to make some of that safe: + /// assert_eq!( + /// to_html_with_options( + /// "<iframe>", + /// &Options { + /// parse: ParseOptions::gfm(), + /// compile: CompileOptions { + /// allow_dangerous_html: true, + /// gfm_tagfilter: true, + /// ..CompileOptions::default() + /// } + /// } + /// )?, + /// "<iframe>" + /// ); + /// # Ok(()) + /// # } + /// ``` + /// + /// ## References + /// + /// * [*§ 6.1 Disallowed Raw HTML (extension)* in GFM](https://github.github.com/gfm/#disallowed-raw-html-extension-) + /// * [`cmark-gfm#extensions/tagfilter.c`](https://github.com/github/cmark-gfm/blob/master/extensions/tagfilter.c) + pub gfm_tagfilter: bool, +} + +impl CompileOptions { + /// GFM. + /// + /// GFM stands for **GitHub flavored markdown**. + /// On the compilation side, GFM turns on the GFM tag filter. + /// The tagfilter is useless, but it’s included here for consistency, and + /// this method exists for parity to parse options. + /// + /// For more information, see the GFM specification: + /// <https://github.github.com/gfm/>. + pub fn gfm() -> Self { + Self { + gfm_tagfilter: true, + ..Self::default() + } + } +} + +/// Configuration that describes how to parse from markdown. +/// +/// You can use this: +/// +/// * To control what markdown constructs are turned on and off +/// * To control some of those constructs +/// * To add support for certain programming languages when parsing MDX +/// +/// In most cases, you will want to use the default trait or `gfm` method. +/// +/// ## Examples +/// +/// ``` +/// use markdown::ParseOptions; +/// # fn main() { +/// +/// // Use the default trait to parse markdown according to `CommonMark`: +/// let commonmark = ParseOptions::default(); +/// +/// // Use the `gfm` method to parse markdown according to GFM: +/// let gfm = ParseOptions::gfm(); +/// # } +/// ``` +#[allow(clippy::struct_excessive_bools)] +pub struct ParseOptions { + // Note: when adding fields, don’t forget to add them to `fmt::Debug` below. + /// Which constructs to enable and disable. + /// + /// The default is to follow `CommonMark`. + /// + /// ## Examples + /// + /// ``` + /// use markdown::{to_html, to_html_with_options, Constructs, Options, ParseOptions}; + /// # fn main() -> Result<(), String> { + /// + /// // `markdown-rs` follows CommonMark by default: + /// assert_eq!( + /// to_html(" indented code?"), + /// "<pre><code>indented code?\n</code></pre>" + /// ); + /// + /// // Pass `constructs` to choose what to enable and disable: + /// assert_eq!( + /// to_html_with_options( + /// " indented code?", + /// &Options { + /// parse: ParseOptions { + /// constructs: Constructs { + /// code_indented: false, + /// ..Constructs::default() + /// }, + /// ..ParseOptions::default() + /// }, + /// ..Options::default() + /// } + /// )?, + /// "<p>indented code?</p>" + /// ); + /// # Ok(()) + /// # } + /// ``` + pub constructs: Constructs, + + /// Whether to support GFM strikethrough with a single tilde + /// + /// This option does nothing if `gfm_strikethrough` is not turned on in + /// `constructs`. + /// This option does not affect strikethrough with double tildes. + /// + /// The default is `true`, which follows how markdown on `github.com` + /// works, as strikethrough with single tildes is supported. + /// Pass `false`, to follow the GFM spec more strictly, by not allowing + /// strikethrough with single tildes. + /// + /// ## Examples + /// + /// ``` + /// use markdown::{to_html_with_options, Constructs, Options, ParseOptions}; + /// # fn main() -> Result<(), String> { + /// + /// // `markdown-rs` supports single tildes by default: + /// assert_eq!( + /// to_html_with_options( + /// "~a~", + /// &Options { + /// parse: ParseOptions { + /// constructs: Constructs::gfm(), + /// ..ParseOptions::default() + /// }, + /// ..Options::default() + /// } + /// )?, + /// "<p><del>a</del></p>" + /// ); + /// + /// // Pass `gfm_strikethrough_single_tilde: false` to turn that off: + /// assert_eq!( + /// to_html_with_options( + /// "~a~", + /// &Options { + /// parse: ParseOptions { + /// constructs: Constructs::gfm(), + /// gfm_strikethrough_single_tilde: false, + /// ..ParseOptions::default() + /// }, + /// ..Options::default() + /// } + /// )?, + /// "<p>~a~</p>" + /// ); + /// # Ok(()) + /// # } + /// ``` + pub gfm_strikethrough_single_tilde: bool, + + /// Whether to support math (text) with a single dollar + /// + /// This option does nothing if `math_text` is not turned on in + /// `constructs`. + /// This option does not affect math (text) with two or more dollars. + /// + /// The default is `true`, which is more close to how code (text) and + /// Pandoc work, as it allows math with a single dollar to form. + /// However, single dollars can interfere with “normal” dollars in text. + /// Pass `false`, to only allow math (text) to form when two or more + /// dollars are used. + /// + /// ## Examples + /// + /// ``` + /// use markdown::{to_html_with_options, Constructs, Options, ParseOptions}; + /// # fn main() -> Result<(), String> { + /// + /// // `markdown-rs` supports single dollars by default: + /// assert_eq!( + /// to_html_with_options( + /// "$a$", + /// &Options { + /// parse: ParseOptions { + /// constructs: Constructs { + /// math_text: true, + /// ..Constructs::default() + /// }, + /// ..ParseOptions::default() + /// }, + /// ..Options::default() + /// } + /// )?, + /// "<p><code class=\"language-math math-inline\">a</code></p>" + /// ); + /// + /// // Pass `math_text_single_dollar: false` to turn that off: + /// assert_eq!( + /// to_html_with_options( + /// "$a$", + /// &Options { + /// parse: ParseOptions { + /// constructs: Constructs { + /// math_text: true, + /// ..Constructs::default() + /// }, + /// math_text_single_dollar: false, + /// ..ParseOptions::default() + /// }, + /// ..Options::default() + /// } + /// )?, + /// "<p>$a$</p>" + /// ); + /// # Ok(()) + /// # } + /// ``` + pub math_text_single_dollar: bool, + + /// Function to parse expressions with. + /// + /// This function can be used to add support for arbitrary programming + /// languages within expressions. + /// + /// It only makes sense to pass this when compiling to a syntax tree + /// with [`to_mdast()`][]. + /// + /// For an example that adds support for JavaScript with SWC, see + /// `tests/test_utils/mod.rs`. + pub mdx_expression_parse: Option<Box<MdxExpressionParse>>, + + /// Function to parse ESM with. + /// + /// This function can be used to add support for arbitrary programming + /// languages within ESM blocks, however, the keywords (`export`, + /// `import`) are currently hardcoded JavaScript-specific. + /// + /// > 👉 **Note**: please raise an issue if you’re interested in working on + /// > MDX that is aware of, say, Rust, or other programming languages. + /// + /// It only makes sense to pass this when compiling to a syntax tree + /// with [`to_mdast()`][]. + /// + /// For an example that adds support for JavaScript with SWC, see + /// `tests/test_utils/mod.rs`. + pub mdx_esm_parse: Option<Box<MdxEsmParse>>, + // Note: when adding fields, don’t forget to add them to `fmt::Debug` below. +} + +impl fmt::Debug for ParseOptions { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_struct("ParseOptions") + .field("constructs", &self.constructs) + .field( + "gfm_strikethrough_single_tilde", + &self.gfm_strikethrough_single_tilde, + ) + .field("math_text_single_dollar", &self.math_text_single_dollar) + .field( + "mdx_expression_parse", + &self.mdx_expression_parse.as_ref().map(|_d| "[Function]"), + ) + .field( + "mdx_esm_parse", + &self.mdx_esm_parse.as_ref().map(|_d| "[Function]"), + ) + .finish() + } +} + +impl Default for ParseOptions { + /// `CommonMark` defaults. + fn default() -> Self { + Self { + constructs: Constructs::default(), + gfm_strikethrough_single_tilde: true, + math_text_single_dollar: true, + mdx_expression_parse: None, + mdx_esm_parse: None, + } + } +} + +impl ParseOptions { + /// GFM. + /// + /// GFM stands for GitHub flavored markdown. + /// GFM extends `CommonMark` and adds support for autolink literals, + /// footnotes, strikethrough, tables, and tasklists. + /// + /// For more information, see the GFM specification: + /// <https://github.github.com/gfm/> + pub fn gfm() -> Self { + Self { + constructs: Constructs::gfm(), + ..Self::default() + } + } + + /// MDX. + /// + /// This turns on `CommonMark`, turns off some conflicting constructs + /// (autolinks, code (indented), and HTML), and turns on MDX (ESM, + /// expressions, and JSX). + /// + /// For more information, see the MDX website: + /// <https://mdxjs.com>. + /// + /// > 👉 **Note**: to support ESM, you *must* pass + /// > [`mdx_esm_parse`][MdxEsmParse] in [`ParseOptions`][] too. + /// > Otherwise, ESM is treated as normal markdown. + /// > + /// > You *can* pass + /// > [`mdx_expression_parse`][MdxExpressionParse] + /// > to parse expressions according to a certain grammar (typically, a + /// > programming language). + /// > Otherwise, expressions are parsed with a basic algorithm that only + /// > cares about braces. + pub fn mdx() -> Self { + Self { + constructs: Constructs::mdx(), + ..Self::default() + } + } +} + +/// Configuration that describes how to parse from markdown and compile to +/// HTML. +/// +/// In most cases, you will want to use the default trait or `gfm` method. +/// +/// ## Examples +/// +/// ``` +/// use markdown::Options; +/// # fn main() { +/// +/// // Use the default trait to compile markdown to HTML according to `CommonMark`: +/// let commonmark = Options::default(); +/// +/// // Use the `gfm` method to compile markdown to HTML according to GFM: +/// let gfm = Options::gfm(); +/// # } +/// ``` +#[allow(clippy::struct_excessive_bools)] +#[derive(Debug, Default)] +pub struct Options { + /// Configuration that describes how to parse from markdown. + pub parse: ParseOptions, + /// Configuration that describes how to compile to HTML. + pub compile: CompileOptions, +} + +impl Options { + /// GFM. + /// + /// GFM stands for GitHub flavored markdown. + /// GFM extends `CommonMark` and adds support for autolink literals, + /// footnotes, strikethrough, tables, and tasklists. + /// On the compilation side, GFM turns on the GFM tag filter. + /// The tagfilter is useless, but it’s included here for consistency. + /// + /// For more information, see the GFM specification: + /// <https://github.github.com/gfm/> + pub fn gfm() -> Self { + Self { + parse: ParseOptions::gfm(), + compile: CompileOptions::gfm(), + } + } +} + +#[cfg(test)] +mod tests { + extern crate std; + use super::*; + use crate::util::mdx::Signal; + use alloc::format; + + #[test] + fn test_constructs() { + Constructs::default(); + Constructs::gfm(); + Constructs::mdx(); + + let constructs = Constructs::default(); + assert!(constructs.attention, "should default to `CommonMark` (1)"); + assert!( + !constructs.gfm_autolink_literal, + "should default to `CommonMark` (2)" + ); + assert!( + !constructs.mdx_jsx_flow, + "should default to `CommonMark` (3)" + ); + assert!( + !constructs.frontmatter, + "should default to `CommonMark` (4)" + ); + + let constructs = Constructs::gfm(); + assert!(constructs.attention, "should support `gfm` shortcut (1)"); + assert!( + constructs.gfm_autolink_literal, + "should support `gfm` shortcut (2)" + ); + assert!( + !constructs.mdx_jsx_flow, + "should support `gfm` shortcut (3)" + ); + assert!(!constructs.frontmatter, "should support `gfm` shortcut (4)"); + + let constructs = Constructs::mdx(); + assert!(constructs.attention, "should support `gfm` shortcut (1)"); + assert!( + !constructs.gfm_autolink_literal, + "should support `mdx` shortcut (2)" + ); + assert!(constructs.mdx_jsx_flow, "should support `mdx` shortcut (3)"); + assert!(!constructs.frontmatter, "should support `mdx` shortcut (4)"); + } + + #[test] + fn test_parse_options() { + ParseOptions::default(); + ParseOptions::gfm(); + ParseOptions::mdx(); + + let options = ParseOptions::default(); + assert!( + options.constructs.attention, + "should default to `CommonMark` (1)" + ); + assert!( + !options.constructs.gfm_autolink_literal, + "should default to `CommonMark` (2)" + ); + assert!( + !options.constructs.mdx_jsx_flow, + "should default to `CommonMark` (3)" + ); + + let options = ParseOptions::gfm(); + assert!( + options.constructs.attention, + "should support `gfm` shortcut (1)" + ); + assert!( + options.constructs.gfm_autolink_literal, + "should support `gfm` shortcut (2)" + ); + assert!( + !options.constructs.mdx_jsx_flow, + "should support `gfm` shortcut (3)" + ); + + let options = ParseOptions::mdx(); + assert!( + options.constructs.attention, + "should support `mdx` shortcut (1)" + ); + assert!( + !options.constructs.gfm_autolink_literal, + "should support `mdx` shortcut (2)" + ); + assert!( + options.constructs.mdx_jsx_flow, + "should support `mdx` shortcut (3)" + ); + + assert_eq!( + format!("{:?}", ParseOptions::default()), + "ParseOptions { constructs: Constructs { attention: true, autolink: true, block_quote: true, character_escape: true, character_reference: true, code_indented: true, code_fenced: true, code_text: true, definition: true, frontmatter: false, gfm_autolink_literal: false, gfm_footnote_definition: false, gfm_label_start_footnote: false, gfm_strikethrough: false, gfm_table: false, gfm_task_list_item: false, hard_break_escape: true, hard_break_trailing: true, heading_atx: true, heading_setext: true, html_flow: true, html_text: true, label_start_image: true, label_start_link: true, label_end: true, list_item: true, math_flow: false, math_text: false, mdx_esm: false, mdx_expression_flow: false, mdx_expression_text: false, mdx_jsx_flow: false, mdx_jsx_text: false, thematic_break: true }, gfm_strikethrough_single_tilde: true, math_text_single_dollar: true, mdx_expression_parse: None, mdx_esm_parse: None }", + "should support `Debug` trait" + ); + assert_eq!( + format!("{:?}", ParseOptions { + mdx_esm_parse: Some(Box::new(|_value| { + Signal::Ok + })), + mdx_expression_parse: Some(Box::new(|_value, _kind| { + Signal::Ok + })), + ..Default::default() + }), + "ParseOptions { constructs: Constructs { attention: true, autolink: true, block_quote: true, character_escape: true, character_reference: true, code_indented: true, code_fenced: true, code_text: true, definition: true, frontmatter: false, gfm_autolink_literal: false, gfm_footnote_definition: false, gfm_label_start_footnote: false, gfm_strikethrough: false, gfm_table: false, gfm_task_list_item: false, hard_break_escape: true, hard_break_trailing: true, heading_atx: true, heading_setext: true, html_flow: true, html_text: true, label_start_image: true, label_start_link: true, label_end: true, list_item: true, math_flow: false, math_text: false, mdx_esm: false, mdx_expression_flow: false, mdx_expression_text: false, mdx_jsx_flow: false, mdx_jsx_text: false, thematic_break: true }, gfm_strikethrough_single_tilde: true, math_text_single_dollar: true, mdx_expression_parse: Some(\"[Function]\"), mdx_esm_parse: Some(\"[Function]\") }", + "should support `Debug` trait on mdx functions" + ); + } + + #[test] + fn test_compile_options() { + CompileOptions::default(); + CompileOptions::gfm(); + + let options = CompileOptions::default(); + assert!( + !options.allow_dangerous_html, + "should default to safe `CommonMark` (1)" + ); + assert!( + !options.gfm_tagfilter, + "should default to safe `CommonMark` (2)" + ); + + let options = CompileOptions::gfm(); + assert!( + !options.allow_dangerous_html, + "should support safe `gfm` shortcut (1)" + ); + assert!( + options.gfm_tagfilter, + "should support safe `gfm` shortcut (1)" + ); + } + + #[test] + fn test_options() { + Options::default(); + + let options = Options::default(); + assert!( + options.parse.constructs.attention, + "should default to safe `CommonMark` (1)" + ); + assert!( + !options.parse.constructs.gfm_autolink_literal, + "should default to safe `CommonMark` (2)" + ); + assert!( + !options.parse.constructs.mdx_jsx_flow, + "should default to safe `CommonMark` (3)" + ); + assert!( + !options.compile.allow_dangerous_html, + "should default to safe `CommonMark` (4)" + ); + + let options = Options::gfm(); + assert!( + options.parse.constructs.attention, + "should support safe `gfm` shortcut (1)" + ); + assert!( + options.parse.constructs.gfm_autolink_literal, + "should support safe `gfm` shortcut (2)" + ); + assert!( + !options.parse.constructs.mdx_jsx_flow, + "should support safe `gfm` shortcut (3)" + ); + assert!( + !options.compile.allow_dangerous_html, + "should support safe `gfm` shortcut (4)" + ); + } +} |