Rollup merge of #7279 - xFrednet:7172-adapt-website-to-new-format, r=flip1995

Adapting the lint list to Clippy's new metadata format

This is close to the end of a long living project to rewrite the lint metadata collection for Clippy. Progress on this has been tracked in #7172. This PR adds one of the last missing puzzle pieces, the actual display of all the changes that have been done in the background. A preview can be seen here: [Clippy's lint list](https://xfrednet.github.io/rust-clippy/master/index.html)

The styling has been discussed on [zulip](https://rust-lang.zulipchat.com/#narrow/stream/257328-clippy/topic/Styling.20feedback.20for.20Clippy's.20lint.20list/near/239601067) but is still open to suggestion.

Side note: It has been fun working on the website where we don't have unit tests and everything is just tested by playing around. However, it's good that this chaos is contained into this one part of Clippy. :bug:

---

Closes: #1303
Closes: #4310

This actually closes fewer things than I thought it would...

changelog: Reworked Clippy's [website](https://rust-lang.github.io/rust-clippy/master/index.html):
changelog: * Added applicability information about lints
changelog: * Added a link to jump to the specific lint implementation
changelog: * Adapted some styling and improved loading time

r? `@flip1995`

1 files changed, 26 insertions, 10 deletions

diff --git a/clippy_lints/src/utils/internal_lints/metadata_collector.rs b/clippy_lints/src/utils/internal_lints/metadata_collector.rs
index 3eccc89cdeb..c9234a85dd2 100644
--- a/clippy_lints/src/utils/internal_lints/metadata_collector.rs
+++ b/clippy_lints/src/utils/internal_lints/metadata_collector.rs
@@ -114,6 +114,8 @@ const DEPRECATED_LINT_TYPE: [&str; 3] = ["clippy_lints", "deprecated_lints", "Cl
 
 /// The index of the applicability name of `paths::APPLICABILITY_VALUES`
 const APPLICABILITY_NAME_INDEX: usize = 2;
+/// This applicability will be set for unresolved applicability values.
+const APPLICABILITY_UNRESOLVED_STR: &str = "Unresolved";
 
 declare_clippy_lint! {
     /// **What it does:** Collects metadata about clippy lints for the website.
@@ -192,7 +194,7 @@ impl Drop for MetadataCollector {
         let mut lints = std::mem::take(&mut self.lints).into_sorted_vec();
         lints
             .iter_mut()
-            .for_each(|x| x.applicability = applicability_info.remove(&x.id));
+            .for_each(|x| x.applicability = Some(applicability_info.remove(&x.id).unwrap_or_default()));
 
         // Outputting
         if Path::new(OUTPUT_FILE).exists() {
@@ -208,7 +210,7 @@ struct LintMetadata {
     id: String,
     id_span: SerializableSpan,
     group: String,
-    level: &'static str,
+    level: String,
     docs: String,
     /// This field is only used in the output and will only be
     /// mapped shortly before the actual output.
@@ -221,7 +223,7 @@ impl LintMetadata {
             id,
             id_span,
             group,
-            level,
+            level: level.to_string(),
             docs,
             applicability: None,
         }
@@ -269,14 +271,16 @@ impl Serialize for ApplicabilityInfo {
     where
         S: Serializer,
     {
-        let index = self.applicability.unwrap_or_default();
-
         let mut s = serializer.serialize_struct("ApplicabilityInfo", 2)?;
         s.serialize_field("is_multi_part_suggestion", &self.is_multi_part_suggestion)?;
-        s.serialize_field(
-            "applicability",
-            &paths::APPLICABILITY_VALUES[index][APPLICABILITY_NAME_INDEX],
-        )?;
+        if let Some(index) = self.applicability {
+            s.serialize_field(
+                "applicability",
+                &paths::APPLICABILITY_VALUES[index][APPLICABILITY_NAME_INDEX],
+            )?;
+        } else {
+            s.serialize_field("applicability", APPLICABILITY_UNRESOLVED_STR)?;
+        }
         s.end()
     }
 }
@@ -486,6 +490,13 @@ fn extract_attr_docs_or_lint(cx: &LateContext<'_>, item: &Item<'_>) -> Option<St
 /// ```
 ///
 /// Would result in `Hello world!\n=^.^=\n`
+///
+/// ---
+///
+/// This function may modify the doc comment to ensure that the string can be displayed using a
+/// markdown viewer in Clippy's lint list. The following modifications could be applied:
+/// * Removal of leading space after a new line. (Important to display tables)
+/// * Ensures that code blocks only contain language information
 fn extract_attr_docs(cx: &LateContext<'_>, item: &Item<'_>) -> Option<String> {
     let attrs = cx.tcx.hir().attrs(item.hir_id());
     let mut lines = attrs.iter().filter_map(ast::Attribute::doc_str);
@@ -510,7 +521,12 @@ fn extract_attr_docs(cx: &LateContext<'_>, item: &Item<'_>) -> Option<String> {
                 continue;
             }
         }
-        docs.push_str(line);
+        // This removes the leading space that the macro translation introduces
+        if let Some(stripped_doc) = line.strip_prefix(' ') {
+            docs.push_str(stripped_doc);
+        } else if !line.is_empty() {
+            docs.push_str(line);
+        }
     }
     Some(docs)
 }