Provide completion for BibTeX field names

src/completion/bibtex/field_name.rs

@@ -0,0 +1,132 @@
+use crate::completion::factory;
+use crate::feature::FeatureRequest;
+use crate::metadata::bibtex_field::BIBTEX_FIELDS;
+use crate::syntax::bibtex::{BibtexFinder, BibtexNode, BibtexVisitor};
+use crate::syntax::text::SyntaxNode;
+use crate::syntax::SyntaxTree;
+use lsp_types::{CompletionItem, CompletionParams};
+
+pub struct BibtexFieldNameCompletionProvider;
+
+impl BibtexFieldNameCompletionProvider {
+    pub async fn execute(request: &FeatureRequest<CompletionParams>) -> Vec<CompletionItem> {
+        if let SyntaxTree::Bibtex(tree) = &request.document.tree {
+            let mut finder = BibtexFinder::new(request.params.position);
+            finder.visit_root(&tree.root);
+            match finder.results.last() {
+                Some(BibtexNode::Field(field)) => {
+                    if field.name.range().contains(request.params.position) {
+                        return Self::generate_items();
+                    }
+                }
+                Some(BibtexNode::Entry(entry)) => {
+                    if !entry.is_comment() && !entry.ty.range().contains(request.params.position) {
+                        if let Some(key) = &entry.key {
+                            if !key.range().contains(request.params.position) {
+                                return Self::generate_items();
+                            }
+                        } else {
+                            return Self::generate_items();
+                        }
+                    }
+                }
+                _ => {}
+            }
+        }
+        Vec::new()
+    }
+
+    fn generate_items() -> Vec<CompletionItem> {
+        BIBTEX_FIELDS
+            .iter()
+            .map(|field| factory::create_field_name(field))
+            .collect()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::completion::latex::data::types::LatexComponentDatabase;
+    use crate::feature::FeatureSpec;
+    use crate::test_feature;
+    use lsp_types::Position;
+
+    #[test]
+    fn test_inside_first_field() {
+        let items = test_feature!(
+            BibtexFieldNameCompletionProvider,
+            FeatureSpec {
+                files: vec![FeatureSpec::file("foo.bib", "@article{foo,\nbar}"),],
+                main_file: "foo.bib",
+                position: Position::new(1, 1),
+                new_name: "",
+                component_database: LatexComponentDatabase::default(),
+            }
+        );
+        assert_eq!(items.len() > 0, true);
+    }
+
+    #[test]
+    fn test_inside_second_field() {
+        let items = test_feature!(
+            BibtexFieldNameCompletionProvider,
+            FeatureSpec {
+                files: vec![FeatureSpec::file(
+                    "foo.bib",
+                    "@article{foo, bar = {baz}, qux}"
+                ),],
+                main_file: "foo.bib",
+                position: Position::new(0, 27),
+                new_name: "",
+                component_database: LatexComponentDatabase::default(),
+            }
+        );
+        assert_eq!(items.len() > 0, true);
+    }
+
+    #[test]
+    fn test_inside_entry() {
+        let items = test_feature!(
+            BibtexFieldNameCompletionProvider,
+            FeatureSpec {
+                files: vec![FeatureSpec::file("foo.bib", "@article{foo, \n}"),],
+                main_file: "foo.bib",
+                position: Position::new(1, 0),
+                new_name: "",
+                component_database: LatexComponentDatabase::default(),
+            }
+        );
+        assert_eq!(items.len() > 0, true);
+    }
+
+    #[test]
+    fn test_inside_content() {
+        let items = test_feature!(
+            BibtexFieldNameCompletionProvider,
+            FeatureSpec {
+                files: vec![FeatureSpec::file("foo.bib", "@article{foo,\nbar = {baz}}"),],
+                main_file: "foo.bib",
+                position: Position::new(1, 7),
+                new_name: "",
+                component_database: LatexComponentDatabase::default(),
+            }
+        );
+        assert_eq!(items.len() == 0, true);
+    }
+
+    #[test]
+    fn test_inside_entry_type() {
+        let items = test_feature!(
+            BibtexFieldNameCompletionProvider,
+            FeatureSpec {
+                files: vec![FeatureSpec::file("foo.bib", "@article{foo,}"),],
+                main_file: "foo.bib",
+                position: Position::new(0, 3),
+                new_name: "",
+                component_database: LatexComponentDatabase::default(),
+            }
+        );
+        assert_eq!(items.len() == 0, true);
+    }
+}

src/completion/bibtex/mod.rs

@@ -0,0 +1 @@
+pub mod field_name;

src/completion/factory.rs

@@ -1,4 +1,5 @@
 use crate::formatting::{BibtexFormatter, BibtexFormattingOptions};
+use crate::metadata::bibtex_field::BibtexField;
 use crate::syntax::bibtex::{BibtexEntry, BibtexToken};
 use lsp_types::*;
 use serde::{Deserialize, Serialize};
@@ -175,3 +176,16 @@ pub fn create_citation(entry: &BibtexEntry, key: &str) -> CompletionItem {
         ..CompletionItem::default()
     }
 }
+
+pub fn create_field_name(field: &BibtexField) -> CompletionItem {
+    CompletionItem {
+        label: Cow::from(field.name),
+        kind: Some(CompletionItemKind::Field),
+        data: Some(CompletionItemData::FieldName.into()),
+        documentation: Some(Documentation::MarkupContent(MarkupContent {
+            kind: MarkupKind::Markdown,
+            value: Cow::from(field.documentation),
+        })),
+        ..CompletionItem::default()
+    }
+}

src/completion/mod.rs

@@ -1,7 +1,9 @@
+mod bibtex;
 mod factory;
 pub mod latex;
 mod quality;
 
+use self::bibtex::field_name::BibtexFieldNameCompletionProvider;
 use self::latex::begin_command::LatexBeginCommandCompletionProvider;
 use self::latex::citation::LatexCitationCompletionProvider;
 use self::latex::color::LatexColorCompletionProvider;
@@ -31,6 +33,7 @@ impl CompletionProvider {
             async move |_| {
                 concat_feature!(
                     &request,
+                    BibtexFieldNameCompletionProvider,
                     LatexKernelEnvironmentCompletionProvider,
                     LatexPgfLibraryCompletionProvider,
                     LatexTikzLibraryCompletionProvider,