Synchronize GitHub Releases with the in-repo changelog

Cargo.toml

@@ -34,6 +34,7 @@ postgres-native-tls = "0.3"
 native-tls = "0.2"
 serde_path_to_error = "0.1.2"
 octocrab = "0.5"
+comrak = "0.8.2"
 
 [dependencies.serde]
 version = "1"

src/changelogs/mod.rs

@@ -0,0 +1,26 @@
+mod rustc;
+
+use comrak::Arena;
+use std::collections::HashMap;
+
+#[derive(Copy, Clone, PartialEq, Eq, Debug, serde::Deserialize)]
+#[serde(rename_all = "kebab-case")]
+pub(crate) enum ChangelogFormat {
+    Rustc,
+}
+
+pub(crate) struct Changelog {
+    versions: HashMap<String, String>,
+}
+
+impl Changelog {
+    pub(crate) fn parse(format: ChangelogFormat, content: &str) -> anyhow::Result<Self> {
+        match format {
+            ChangelogFormat::Rustc => rustc::RustcFormat::new(&Arena::new()).parse(content),
+        }
+    }
+
+    pub(crate) fn version(&self, version: &str) -> Option<&str> {
+        self.versions.get(version).map(|s| s.as_str())
+    }
+}

src/changelogs/rustc.rs

@@ -0,0 +1,150 @@
+use super::Changelog;
+use comrak::{
+    nodes::{Ast, AstNode, NodeHeading, NodeValue},
+    Arena, ComrakOptions,
+};
+use std::cell::RefCell;
+use std::collections::HashMap;
+
+pub(super) struct RustcFormat<'a> {
+    arena: &'a Arena<AstNode<'a>>,
+    current_h1: Option<String>,
+    result: Changelog,
+}
+
+impl<'a> RustcFormat<'a> {
+    pub(super) fn new(arena: &'a Arena<AstNode<'a>>) -> Self {
+        RustcFormat {
+            arena,
+            current_h1: None,
+            result: Changelog {
+                versions: HashMap::new(),
+            },
+        }
+    }
+
+    pub(super) fn parse(mut self, content: &str) -> anyhow::Result<Changelog> {
+        let ast = comrak::parse_document(&self.arena, &content, &ComrakOptions::default());
+
+        let mut section_ast = Vec::new();
+        for child in ast.children() {
+            let child_data = child.data.borrow();
+
+            if let NodeValue::Heading(NodeHeading { level: 1, .. }) = child_data.value {
+                if let Some(h1) = self.current_h1.take() {
+                    self.store_version(h1, section_ast)?;
+                }
+
+                self.current_h1 = Some(String::from_utf8(child_data.content.clone())?);
+                section_ast = Vec::new();
+            } else {
+                section_ast.push(child);
+            }
+        }
+        if let Some(h1) = self.current_h1.take() {
+            self.store_version(h1, section_ast)?;
+        }
+
+        Ok(self.result)
+    }
+
+    fn store_version(&mut self, h1: String, body: Vec<&'a AstNode<'a>>) -> anyhow::Result<()> {
+        // Create a document with only the contents of this section
+        let document = self
+            .arena
+            .alloc(AstNode::new(RefCell::new(Ast::new(NodeValue::Document))));
+        for child in &body {
+            document.append(child);
+        }
+
+        let mut content = Vec::new();
+        comrak::format_commonmark(document, &ComrakOptions::default(), &mut content)?;
+        let content = String::from_utf8(content)?;
+
+        if let Some(version) = h1.split(' ').nth(1) {
+            self.result.versions.insert(version.to_string(), content);
+        } else {
+            println!("skipped version, invalid header: {}", h1);
+        }
+
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    const CONTENT: &str = "\
+Version 1.45.2 (2020-08-03)
+==========================
+
+* [Fix bindings in tuple struct patterns][74954]
+* [Link in another section][69033]
+
+[74954]: https://github.com/rust-lang/rust/issues/74954
+
+Version 1.45.1 (2020-07-30)
+==========================
+
+* [Fix const propagation with references.][73613]
+* [rustfmt accepts rustfmt_skip in cfg_attr again.][73078]
+
+[73613]: https://github.com/rust-lang/rust/pull/73613
+[73078]: https://github.com/rust-lang/rust/issues/73078
+
+Version 1.44.0 (2020-06-04)
+==========================
+
+Language
+--------
+- [You can now use `async/.await` with `#[no_std]` enabled.][69033]
+
+**Syntax-only changes**
+
+- [Expansion-driven outline module parsing][69838]
+```rust
+#[cfg(FALSE)]
+mod foo {
+    mod bar {
+        mod baz; // `foo/bar/baz.rs` doesn't exist, but no error!
+    }
+}
+```
+
+These are still rejected semantically, so you will likely receive an error but
+these changes can be seen and parsed by macros and conditional compilation.
+
+Internal Only
+-------------
+These changes provide no direct user facing benefits, but represent significant
+improvements to the internals and overall performance of rustc and
+related tools.
+
+- [dep_graph Avoid allocating a set on when the number reads are small.][69778]
+
+[69033]: https://github.com/rust-lang/rust/pull/69033/
+[69838]: https://github.com/rust-lang/rust/pull/69838/
+[69778]: https://github.com/rust-lang/rust/pull/69778/
+";
+
+    const EXPECTED_1_45_2: &str = "\
+- [Fix bindings in tuple struct patterns](https://github.com/rust-lang/rust/issues/74954)
+- [Link in another section](https://github.com/rust-lang/rust/pull/69033/)
+";
+
+    #[test]
+    fn test_changelog_parsing() -> anyhow::Result<()> {
+        let arena = Arena::new();
+        let parsed = RustcFormat::new(&arena).parse(CONTENT)?;
+
+        // Ensure the right markdown is generated from each version
+        let version_1_45_2 = parsed.version("1.45.2").expect("missing version 1.45.2");
+        assert_eq!(EXPECTED_1_45_2, version_1_45_2);
+
+        let version_1_44_0 = parsed.version("1.44.0").expect("missing version 1.44.0");
+        assert!(version_1_44_0.contains("Avoid allocating a set"));
+
+        Ok(())
+    }
+}

src/lib.rs

@@ -10,6 +10,7 @@ use std::fmt;
 
 pub mod actions;
 pub mod agenda;
+mod changelogs;
 pub mod config;
 pub mod db;
 pub mod github;