Show BibTeX field documentation when hovering

src/hover/bibtex_field.rs

@@ -0,0 +1,92 @@
+use crate::feature::FeatureRequest;
+use crate::metadata::bibtex_field;
+use crate::syntax::bibtex::ast::{BibtexField, BibtexVisitor};
+use crate::syntax::bibtex::finder::{BibtexFinder, BibtexNode};
+use crate::syntax::text::SyntaxNode;
+use crate::workspace::SyntaxTree;
+use lsp_types::{Hover, HoverContents, MarkupContent, MarkupKind, TextDocumentPositionParams};
+
+pub struct BibtexFieldHoverProvider;
+
+impl BibtexFieldHoverProvider {
+    pub async fn execute(request: &FeatureRequest<TextDocumentPositionParams>) -> Option<Hover> {
+        if let SyntaxTree::Bibtex(tree) = &request.document.tree {
+            let mut finder = BibtexFinder::new(request.params.position);
+            finder.visit_root(&tree.root);
+            for node in finder.results {
+                if let BibtexNode::Field(field) = node {
+                    let documentation = bibtex_field::get_documentation(field.name.text())?;
+                    return Some(Hover {
+                        contents: HoverContents::Markup(MarkupContent {
+                            kind: MarkupKind::Markdown,
+                            value: documentation.to_owned(),
+                        }),
+                        range: None,
+                    });
+                }
+            }
+        }
+        None
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::feature::FeatureTester;
+    use crate::workspace::WorkspaceBuilder;
+    use futures::executor::block_on;
+
+    #[test]
+    fn test_known_field() {
+        let mut builder = WorkspaceBuilder::new();
+        let uri = builder.document("foo.bib", "@article{foo, author = bar}");
+        let request = FeatureTester::new(builder.workspace, uri, 0, 15, "").into();
+
+        let actual = block_on(BibtexFieldHoverProvider::execute(&request));
+
+        let expected = Hover {
+            contents: HoverContents::Markup(MarkupContent {
+                kind: MarkupKind::Markdown,
+                value: bibtex_field::get_documentation("author")
+                    .unwrap()
+                    .to_owned(),
+            }),
+            range: None,
+        };
+        assert_eq!(Some(expected), actual);
+    }
+
+    #[test]
+    fn test_unknown_field() {
+        let mut builder = WorkspaceBuilder::new();
+        let uri = builder.document("foo.bib", "@article{foo, bar = baz}");
+        let request = FeatureTester::new(builder.workspace, uri, 0, 15, "").into();
+
+        let actual = block_on(BibtexFieldHoverProvider::execute(&request));
+
+        assert_eq!(None, actual);
+    }
+
+    #[test]
+    fn test_entry_key() {
+        let mut builder = WorkspaceBuilder::new();
+        let uri = builder.document("foo.bib", "@article{foo, bar = baz}");
+        let request = FeatureTester::new(builder.workspace, uri, 0, 11, "").into();
+
+        let actual = block_on(BibtexFieldHoverProvider::execute(&request));
+
+        assert_eq!(None, actual);
+    }
+
+    #[test]
+    fn test_latex() {
+        let mut builder = WorkspaceBuilder::new();
+        let uri = builder.document("foo.tex", "\\foo");
+        let request = FeatureTester::new(builder.workspace, uri, 0, 1, "").into();
+
+        let actual = block_on(BibtexFieldHoverProvider::execute(&request));
+
+        assert_eq!(None, actual);
+    }
+}

src/hover/mod.rs

@@ -0,0 +1,14 @@
+mod bibtex_field;
+
+use crate::choice_feature;
+use crate::feature::FeatureRequest;
+use crate::hover::bibtex_field::BibtexFieldHoverProvider;
+use lsp_types::{Hover, TextDocumentPositionParams};
+
+pub struct HoverProvider;
+
+impl HoverProvider {
+    pub async fn execute(request: &FeatureRequest<TextDocumentPositionParams>) -> Option<Hover> {
+        choice_feature!(&request, BibtexFieldHoverProvider)
+    }
+}

src/main.rs

@@ -7,8 +7,10 @@ mod feature;
 mod folding;
 mod formatting;
 mod highlight;
+mod hover;
 mod link;
 mod lsp;
+mod metadata;
 mod range;
 mod reference;
 mod rename;