test(linter): more documentation testing

crates/oxc_linter/Cargo.toml

@@ -57,3 +57,4 @@ schemars            = { workspace = true, features = ["indexmap2"] }
 static_assertions = { workspace = true }
 insta             = { workspace = true }
 project-root      = { workspace = true }
+markdown          = { version = "1.0.0-alpha.18" }

crates/oxc_linter/src/rule.rs

@@ -235,12 +235,48 @@ impl RuleWithSeverity {
 #[cfg(test)]
 mod test {
     use crate::rules::RULES;
+    use itertools::Itertools as _;
+    use markdown::{to_html_with_options, Options};
+    use oxc_allocator::Allocator;
+    use oxc_diagnostics::Error;
+    use oxc_parser::Parser;
+    use oxc_span::SourceType;
 
     #[test]
     fn ensure_documentation() {
         assert!(!RULES.is_empty());
+        let options = Options::gfm();
+        let source_type = SourceType::default().with_jsx(true).with_always_strict(true);
+
         for rule in RULES.iter() {
-            assert!(rule.documentation().is_some_and(|s| !s.is_empty()), "{}", rule.name());
+            let name = rule.name();
+            assert!(
+                rule.documentation().is_some_and(|s| !s.is_empty()),
+                "Rule '{name}' is missing documentation."
+            );
+            // will panic if provided invalid markdown
+            let html = to_html_with_options(rule.documentation().unwrap(), &options).unwrap();
+            assert!(!html.is_empty());
+
+            // convert HTML to JSX, then use the parser to ensure valid HTML was generated
+            let jsx =
+                format!("const Documentation = <>{}</>;", html.replace("class=", "className="));
+            let allocator = Allocator::default();
+            let ret = Parser::new(&allocator, &jsx, source_type).parse();
+
+            let has_errors = !ret.errors.is_empty();
+            let errors = ret
+                .errors
+                .into_iter()
+                .map(|error| Error::new(error).with_source_code(jsx.clone()))
+                .map(|e| format!("{e:?}"))
+                .join("\n\n");
+
+            assert!(
+                !ret.panicked && !has_errors,
+                "Documentation for rule '{name}' has invalid syntax: {errors}"
+            );
+            assert!(!ret.program.body.is_empty(), "Documentation for rule '{name}' is empty.");
         }
     }
 }

crates/oxc_linter/src/rules/eslint/for_direction.rs

@@ -35,7 +35,7 @@ declare_oxc_lint!(
     /// ```javascript
     /// for (var i = 0; i < 10; i--) {}
     ///
-    /// for (var = 10; i >= 0; i++) {}
+    /// for (var i = 10; i >= 0; i++) {}
     /// ```
     ForDirection,
     correctness,

crates/oxc_linter/src/table.rs

@@ -125,3 +125,49 @@ impl RuleTableSection {
         s
     }
 }
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use markdown::{to_html_with_options, Options};
+    use std::sync::OnceLock;
+
+    static TABLE: OnceLock<RuleTable> = OnceLock::new();
+
+    fn table() -> &'static RuleTable {
+        TABLE.get_or_init(|| RuleTable::new())
+    }
+
+    #[test]
+    fn test_table_no_links() {
+        let options = Options::gfm();
+        for section in &table().sections {
+            let rendered_table = section.render_markdown_table(None);
+            assert!(!rendered_table.is_empty());
+            assert_eq!(rendered_table.split("\n").count(), 5 + section.rows.len());
+
+            let html = to_html_with_options(&rendered_table, &options).unwrap();
+            assert!(!html.is_empty());
+            assert!(html.contains("<table>"));
+        }
+    }
+
+    #[test]
+    fn test_table_with_links() {
+        const PREFIX: &str = "/foo/bar";
+        const PREFIX_WITH_SLASH: &str = "/foo/bar/";
+
+        let options = Options::gfm();
+
+        for section in &table().sections {
+            let rendered_table = section.render_markdown_table(Some(PREFIX));
+            assert!(!rendered_table.is_empty());
+            assert_eq!(rendered_table.split("\n").count(), 5 + section.rows.len());
+
+            let html = to_html_with_options(&rendered_table, &options).unwrap();
+            assert!(!html.is_empty());
+            assert!(html.contains("<table>"));
+            assert!(html.contains(PREFIX_WITH_SLASH));
+        }
+    }
+}

tasks/website/Cargo.toml

@@ -27,7 +27,14 @@ serde      = { workspace = true }
 bpaf       = { workspace = true, features = ["docgen"] }
 
 [dev-dependencies]
-insta = { workspace = true }
+oxc_allocator   = { workspace = true }
+oxc_diagnostics = { workspace = true }
+oxc_parser      = { workspace = true }
+oxc_span        = { workspace = true }
+
+insta    = { workspace = true }
+markdown = { version = "1.0.0-alpha.18" }
+scraper  = { version = "0.20.0" }
 
 [package.metadata.cargo-shear]
 ignored = ["bpaf"]

tasks/website/src/linter/rules/mod.rs

@@ -1,6 +1,8 @@
 mod doc_page;
 mod html;
 mod table;
+#[cfg(test)]
+mod test;
 
 use std::{
     borrow::Cow,
@@ -95,6 +97,9 @@ fn write_rule_doc_pages(table: &RuleTable, outdir: &Path) {
         let plugin_path = outdir.join(&rule.plugin);
         fs::create_dir_all(&plugin_path).unwrap();
         let page_path = plugin_path.join(format!("{}.md", rule.name));
+        if page_path.exists() {
+            fs::remove_file(&page_path).unwrap();
+        }
         println!("{}", page_path.display());
         let docs = render_rule_docs_page(rule).unwrap();
         fs::write(&page_path, docs).unwrap();

tasks/website/src/linter/rules/test.rs

@@ -0,0 +1,118 @@
+use markdown::{to_html, to_html_with_options, Options};
+use oxc_diagnostics::NamedSource;
+use scraper::{ElementRef, Html, Selector};
+use std::sync::{Arc, OnceLock};
+
+use oxc_allocator::Allocator;
+use oxc_linter::table::RuleTable;
+use oxc_parser::Parser;
+use oxc_span::SourceType;
+
+use super::{render_rule_docs_page, render_rules_table};
+
+static TABLE: OnceLock<RuleTable> = OnceLock::new();
+
+fn table() -> &'static RuleTable {
+    TABLE.get_or_init(|| RuleTable::new())
+}
+
+fn parse(filename: &str, jsx: &str) -> Result<(), String> {
+    let filename = format!("{filename}.tsx");
+    let source_type = SourceType::from_path(&filename).unwrap();
+    parse_type(&filename, jsx, source_type)
+}
+
+fn parse_type(filename: &str, source_text: &str, source_type: SourceType) -> Result<(), String> {
+    let alloc = Allocator::default();
+    let ret = Parser::new(&alloc, source_text, source_type).parse();
+
+    if ret.errors.is_empty() {
+        Ok(())
+    } else {
+        let num_errs = ret.errors.len();
+        let source = Arc::new(NamedSource::new(filename, source_text.to_string()));
+        ret.errors
+            .into_iter()
+            .map(|e| e.with_source_code(Arc::clone(&source)))
+            .for_each(|e| println!("{e:?}"));
+        Err(format!("{} errors occurred while parsing {filename}.jsx", num_errs))
+    }
+}
+
+#[test]
+fn test_rules_table() {
+    const PREFIX: &str = "/docs/guide/usage/linter/rules";
+    let rendered_table = render_rules_table(table(), PREFIX);
+    let html = to_html(&rendered_table);
+    let jsx = format!("const Table = () => <>{html}</>");
+    parse("rules-table", &jsx).unwrap();
+}
+
+#[test]
+fn test_doc_pages() {
+    let mut options = Options::gfm();
+    options.compile.allow_dangerous_html = true;
+
+    for section in &table().sections {
+        let category = section.category;
+        let code = Selector::parse("code").unwrap();
+
+        for row in &section.rows {
+            let filename = format!("{category}/{}/{}", row.plugin, row.name);
+            let docs = render_rule_docs_page(row).unwrap();
+            let docs = to_html_with_options(&docs, &options).unwrap();
+            let docs = if let Some(end_of_autogen_comment) = docs.find("-->") {
+                &docs[end_of_autogen_comment + 4..]
+            } else {
+                &docs
+            };
+
+            // ensure the docs are valid JSX
+            {
+                let jsx = format!("const Docs = () => <>{docs}</>");
+                parse(&filename, &jsx).unwrap();
+            }
+
+            // ensure code examples are valid
+            {
+                let html = Html::parse_fragment(&docs);
+                assert!(html.errors.is_empty(), "HTML parsing errors: {:#?}", html.errors);
+                for code_el in html.select(&code) {
+                    let inner = code_el.inner_html();
+                    assert!(
+                        !inner.trim().is_empty(),
+                        "Rule '{}' has an empty code snippet",
+                        row.name
+                    );
+                    let inner = inner.replace("&lt;", "<").replace("&gt;", ">");
+                    let filename = filename.clone() + "/code-snippet";
+                    let source_type = source_type_from_code_element(code_el);
+                    parse_type(&filename, &inner, source_type).unwrap();
+                }
+            }
+        }
+    }
+}
+
+fn default_source() -> SourceType {
+    SourceType::default().with_typescript(true).with_jsx(true).with_always_strict(true)
+}
+fn source_type_from_code_element(code: ElementRef) -> SourceType {
+    let Some(class) = code.attr("class") else {
+        return default_source();
+    };
+    let maybe_class = class.split('-').collect::<Vec<_>>();
+    let ["language", lang] = maybe_class.as_slice() else {
+        return default_source();
+    };
+
+    match *lang {
+        "javascript" | "js" => SourceType::default().with_always_strict(true),
+        "jsx" => SourceType::default().with_jsx(true).with_always_strict(true),
+        "typescript" | "ts" => SourceType::default().with_typescript(true).with_always_strict(true),
+        "tsx" => {
+            SourceType::default().with_typescript(true).with_jsx(true).with_always_strict(true)
+        }
+        _ => default_source(),
+    }
+}