Provide foldings for LaTeX environments

src/folding/latex_environment.rs

@@ -0,0 +1,67 @@
+use crate::feature::FeatureRequest;
+use crate::syntax::latex::analysis::environment::LatexEnvironmentAnalyzer;
+use crate::syntax::latex::ast::LatexVisitor;
+use crate::syntax::text::SyntaxNode;
+use crate::workspace::SyntaxTree;
+use lsp_types::{FoldingRange, FoldingRangeKind, FoldingRangeParams};
+
+pub struct LatexEnvironmentFoldingProvider;
+
+impl LatexEnvironmentFoldingProvider {
+    pub async fn execute(request: &FeatureRequest<FoldingRangeParams>) -> Vec<FoldingRange> {
+        let mut foldings = Vec::new();
+        if let SyntaxTree::Latex(tree) = &request.document.tree {
+            let mut analyzer = LatexEnvironmentAnalyzer::new();
+            analyzer.visit_root(&tree.root);
+            for environment in &analyzer.environments {
+                let start = environment.left.command.end();
+                let end = environment.right.command.start();
+                foldings.push(FoldingRange {
+                    start_line: start.line,
+                    start_character: Some(start.character),
+                    end_line: end.line,
+                    end_character: Some(end.character),
+                    kind: Some(FoldingRangeKind::Region),
+                })
+            }
+        }
+        foldings
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::feature::FeatureTester;
+    use crate::workspace::WorkspaceBuilder;
+    use futures::executor;
+
+    #[test]
+    fn test_multiline() {
+        let mut builder = WorkspaceBuilder::new();
+        let uri = builder.document("foo.tex", "\\begin{foo}\n\\end{foo}");
+        let request = FeatureTester::new(builder.workspace, uri, 0, 0, "").into();
+
+        let results = executor::block_on(LatexEnvironmentFoldingProvider::execute(&request));
+
+        let folding = FoldingRange {
+            start_line: 0,
+            start_character: Some(11),
+            end_line: 1,
+            end_character: Some(0),
+            kind: Some(FoldingRangeKind::Region),
+        };
+        assert_eq!(vec![folding], results);
+    }
+
+    #[test]
+    fn test_bibtex() {
+        let mut builder = WorkspaceBuilder::new();
+        let uri = builder.document("foo.bib", "@article{foo, bar = baz}");
+        let request = FeatureTester::new(builder.workspace, uri, 0, 0, "").into();
+
+        let results = executor::block_on(LatexEnvironmentFoldingProvider::execute(&request));
+
+        assert_eq!(results, Vec::new());
+    }
+}

src/folding/mod.rs

@@ -1 +1,2 @@
 mod bibtex_declaration;
+mod latex_environment;