Include theorem environments in completion

src/completion/factory.rs

@@ -46,7 +46,7 @@ impl<'a> LatexComponentId<'a> {
     pub fn detail(&self) -> Cow<'static, str> {
         match self {
             LatexComponentId::Kernel => "built-in".into(),
-            LatexComponentId::User => "unknown".into(),
+            LatexComponentId::User => "user-defined".into(),
             LatexComponentId::Component(files) => files.join(", ").into(),
         }
     }

src/completion/latex/mod.rs

@@ -9,5 +9,6 @@ pub mod include;
 pub mod kernel;
 pub mod label;
 pub mod symbol;
+pub mod theorem;
 pub mod tikz;
 pub mod user;

src/completion/latex/theorem.rs

@@ -0,0 +1,68 @@
+use crate::completion::factory::{self, LatexComponentId};
+use crate::completion::latex::combinators;
+use crate::feature::{FeatureProvider, FeatureRequest};
+use crate::syntax::SyntaxTree;
+use futures_boxed::boxed;
+use lsp_types::{CompletionItem, CompletionParams, TextEdit};
+
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+pub struct LatexTheoremEnvironmentCompletionProvider;
+
+impl FeatureProvider for LatexTheoremEnvironmentCompletionProvider {
+    type Params = CompletionParams;
+    type Output = Vec<CompletionItem>;
+
+    #[boxed]
+    async fn execute<'a>(&'a self, request: &'a FeatureRequest<Self::Params>) -> Self::Output {
+        combinators::environment(request, async move |_, name_range| {
+            let mut items = Vec::new();
+            for document in request.related_documents() {
+                if let SyntaxTree::Latex(tree) = &document.tree {
+                    for theorem in &tree.theorem_definitions {
+                        let name = theorem.name().text().to_owned();
+                        let text_edit = TextEdit::new(name_range, name.clone().into());
+                        let item = factory::environment(
+                            request,
+                            name.into(),
+                            text_edit,
+                            &LatexComponentId::User,
+                        );
+                        items.push(item);
+                    }
+                }
+            }
+            items
+        })
+        .await
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::feature::{test_feature, FeatureSpec};
+    use lsp_types::{Position, Range};
+    use std::borrow::Cow;
+
+    #[test]
+    fn test() {
+        let items = test_feature(
+            LatexTheoremEnvironmentCompletionProvider,
+            FeatureSpec {
+                files: vec![FeatureSpec::file(
+                    "foo.tex",
+                    "\\newtheorem{theorem}{Theorem}\n\\begin{th}",
+                )],
+                main_file: "foo.tex",
+                position: Position::new(1, 8),
+                ..FeatureSpec::default()
+            },
+        );
+        assert_eq!(items.len(), 1);
+        assert_eq!(items[0].label, Cow::from("theorem"));
+        assert_eq!(
+            items[0].text_edit.as_ref().map(|edit| edit.range),
+            Some(Range::new_simple(1, 7, 1, 9))
+        );
+    }
+}

src/completion/mod.rs

@@ -18,6 +18,7 @@ use self::latex::include::LatexIncludeCompletionProvider;
 use self::latex::kernel::*;
 use self::latex::label::LatexLabelCompletionProvider;
 use self::latex::symbol::*;
+use self::latex::theorem::LatexTheoremEnvironmentCompletionProvider;
 use self::latex::tikz::*;
 use self::latex::user::*;
 use self::quality::OrderByQualityCompletionProvider;
@@ -45,6 +46,7 @@ impl CompletionProvider {
                 Box::new(LatexTikzLibraryCompletionProvider),
                 Box::new(LatexColorCompletionProvider),
                 Box::new(LatexColorModelCompletionProvider),
+                Box::new(LatexTheoremEnvironmentCompletionProvider),
                 Box::new(LatexComponentEnvironmentProvider),
                 Box::new(LatexKernelEnvironmentCompletionProvider),
                 Box::new(LatexLabelCompletionProvider),