ide: add hover for column in create index (#763)

Author: sbdchd

crates/squawk_ide/src/hover.rs

@@ -0,0 +1,260 @@
+use crate::binder;
+use crate::offsets::token_from_offset;
+use crate::resolve;
+use rowan::TextSize;
+use squawk_syntax::ast::{self, AstNode};
+
+pub fn hover(file: &ast::SourceFile, offset: TextSize) -> Option<String> {
+    let token = token_from_offset(file, offset)?;
+    let parent = token.parent()?;
+
+    let name_ref = ast::NameRef::cast(parent)?;
+
+    if !is_column_ref(&name_ref) {
+        return None;
+    }
+
+    let column_name = name_ref.syntax().text().to_string();
+
+    let create_index = name_ref
+        .syntax()
+        .ancestors()
+        .find_map(ast::CreateIndex::cast)?;
+
+    let relation_name = create_index.relation_name()?;
+    let path = relation_name.path()?;
+
+    let binder = binder::bind(file);
+
+    let (schema, table_name) = resolve::resolve_table_info(&binder, &path)?;
+
+    let column_ptr = resolve::resolve_name_ref(&binder, &name_ref)?;
+
+    let root = file.syntax();
+    let column_name_node = column_ptr.to_node(root);
+
+    let column = column_name_node.ancestors().find_map(ast::Column::cast)?;
+
+    let ty = column.ty()?;
+
+    Some(format!(
+        "{schema}.{table_name}.{column_name} {}",
+        ty.syntax().text()
+    ))
+}
+
+fn is_column_ref(name_ref: &ast::NameRef) -> bool {
+    for ancestor in name_ref.syntax().ancestors() {
+        if ast::PartitionItem::can_cast(ancestor.kind()) {
+            return true;
+        }
+        if ast::CreateIndex::can_cast(ancestor.kind()) {
+            return true;
+        }
+    }
+    false
+}
+
+#[cfg(test)]
+mod test {
+    use crate::hover::hover;
+    use crate::test_utils::fixture;
+    use annotate_snippets::{AnnotationKind, Level, Renderer, Snippet, renderer::DecorStyle};
+    use insta::assert_snapshot;
+    use squawk_syntax::ast;
+
+    #[track_caller]
+    fn check_hover(sql: &str) -> String {
+        check_hover_(sql).expect("should find hover information")
+    }
+
+    #[track_caller]
+    fn check_hover_(sql: &str) -> Option<String> {
+        let (mut offset, sql) = fixture(sql);
+        offset = offset.checked_sub(1.into()).unwrap_or_default();
+        let parse = ast::SourceFile::parse(&sql);
+        assert_eq!(parse.errors(), vec![]);
+        let file: ast::SourceFile = parse.tree();
+
+        if let Some(type_info) = hover(&file, offset) {
+            let offset_usize: usize = offset.into();
+            let title = format!("hover: {}", type_info);
+            let group = Level::INFO.primary_title(&title).element(
+                Snippet::source(&sql).fold(true).annotation(
+                    AnnotationKind::Context
+                        .span(offset_usize..offset_usize + 1)
+                        .label("hover"),
+                ),
+            );
+            let renderer = Renderer::plain().decor_style(DecorStyle::Unicode);
+            return Some(
+                renderer
+                    .render(&[group])
+                    .to_string()
+                    // neater
+                    .replace("info: hover:", "hover:"),
+            );
+        }
+        None
+    }
+
+    fn hover_not_found(sql: &str) {
+        assert!(
+            check_hover_(sql).is_none(),
+            "Should not find hover information"
+        );
+    }
+
+    #[test]
+    fn hover_column_in_create_index() {
+        assert_snapshot!(check_hover("
+create table users(id int, email text);
+create index idx_email on users(email$0);
+"), @r"
+        hover: public.users.email text
+          ╭▸ 
+        3 │ create index idx_email on users(email);
+          ╰╴                                    ─ hover
+        ");
+    }
+
+    #[test]
+    fn hover_column_int_type() {
+        assert_snapshot!(check_hover("
+create table users(id int, email text);
+create index idx_id on users(id$0);
+"), @r"
+        hover: public.users.id int
+          ╭▸ 
+        3 │ create index idx_id on users(id);
+          ╰╴                              ─ hover
+        ");
+    }
+
+    #[test]
+    fn hover_column_with_schema() {
+        assert_snapshot!(check_hover("
+create table public.users(id int, email text);
+create index idx_email on public.users(email$0);
+"), @r"
+        hover: public.users.email text
+          ╭▸ 
+        3 │ create index idx_email on public.users(email);
+          ╰╴                                           ─ hover
+        ");
+    }
+
+    #[test]
+    fn hover_column_temp_table() {
+        assert_snapshot!(check_hover("
+create temp table users(id int, email text);
+create index idx_email on users(email$0);
+"), @r"
+        hover: pg_temp.users.email text
+          ╭▸ 
+        3 │ create index idx_email on users(email);
+          ╰╴                                    ─ hover
+        ");
+    }
+
+    #[test]
+    fn hover_column_multiple_columns() {
+        assert_snapshot!(check_hover("
+create table users(id int, email text, name varchar(100));
+create index idx_users on users(id, email$0, name);
+"), @r"
+        hover: public.users.email text
+          ╭▸ 
+        3 │ create index idx_users on users(id, email, name);
+          ╰╴                                        ─ hover
+        ");
+    }
+
+    #[test]
+    fn hover_column_varchar() {
+        assert_snapshot!(check_hover("
+create table users(id int, name varchar(100));
+create index idx_name on users(name$0);
+"), @r"
+        hover: public.users.name varchar(100)
+          ╭▸ 
+        3 │ create index idx_name on users(name);
+          ╰╴                                  ─ hover
+        ");
+    }
+
+    #[test]
+    fn hover_column_bigint() {
+        assert_snapshot!(check_hover("
+create table metrics(value bigint);
+create index idx_value on metrics(value$0);
+"), @r"
+        hover: public.metrics.value bigint
+          ╭▸ 
+        3 │ create index idx_value on metrics(value);
+          ╰╴                                      ─ hover
+        ");
+    }
+
+    #[test]
+    fn hover_column_timestamp() {
+        assert_snapshot!(check_hover("
+create table events(created_at timestamp with time zone);
+create index idx_created on events(created_at$0);
+"), @r"
+        hover: public.events.created_at timestamp with time zone
+          ╭▸ 
+        3 │ create index idx_created on events(created_at);
+          ╰╴                                            ─ hover
+        ");
+    }
+
+    #[test]
+    fn hover_column_with_search_path() {
+        assert_snapshot!(check_hover(r#"
+set search_path to myschema;
+create table myschema.users(id int, email text);
+create index idx_email on users(email$0);
+"#), @r"
+        hover: myschema.users.email text
+          ╭▸ 
+        4 │ create index idx_email on users(email);
+          ╰╴                                    ─ hover
+        ");
+    }
+
+    #[test]
+    fn hover_column_explicit_schema_overrides_search_path() {
+        assert_snapshot!(check_hover(r#"
+set search_path to myschema;
+create table public.users(id int, email text);
+create table myschema.users(value bigint);
+create index idx_email on public.users(email$0);
+"#), @r"
+        hover: public.users.email text
+          ╭▸ 
+        5 │ create index idx_email on public.users(email);
+          ╰╴                                           ─ hover
+        ");
+    }
+
+    #[test]
+    fn hover_not_on_table_name() {
+        hover_not_found(
+            "
+create table users(id int);
+create index idx on users$0(id);
+",
+        );
+    }
+
+    #[test]
+    fn hover_not_on_index_name() {
+        hover_not_found(
+            "
+create table users(id int);
+create index idx$0 on users(id);
+",
+        );
+    }
+}

crates/squawk_ide/src/lib.rs

@@ -5,6 +5,7 @@ pub mod expand_selection;
 pub mod find_references;
 mod generated;
 pub mod goto_definition;
+pub mod hover;
 mod offsets;
 mod resolve;
 mod scope;

crates/squawk_ide/src/resolve.rs

@@ -5,7 +5,8 @@ use squawk_syntax::{
 };
 
 use crate::binder::Binder;
-use crate::symbols::{Name, Schema, SymbolKind};
+pub(crate) use crate::symbols::Schema;
+use crate::symbols::{Name, SymbolKind};
 use squawk_syntax::SyntaxNode;
 
 #[derive(Debug)]
@@ -180,3 +181,52 @@ fn extract_schema_name(path: &ast::Path) -> Option<Schema> {
         .and_then(|s| s.name_ref())
         .map(|name_ref| Schema(Name::new(name_ref.syntax().text().to_string())))
 }
+
+pub(crate) fn resolve_table_info(binder: &Binder, path: &ast::Path) -> Option<(Schema, String)> {
+    let table_name_str = extract_table_name_from_path(path)?;
+    let schema = extract_schema_from_path(path);
+
+    let table_name_normalized = Name::new(table_name_str.clone());
+    let symbols = binder.scopes[binder.root_scope()].get(&table_name_normalized)?;
+
+    if let Some(schema_name) = schema {
+        let schema_normalized = Schema::new(schema_name);
+        let symbol_id = symbols.iter().copied().find(|id| {
+            let symbol = &binder.symbols[*id];
+            symbol.kind == SymbolKind::Table && symbol.schema == schema_normalized
+        })?;
+        let symbol = &binder.symbols[symbol_id];
+        return Some((symbol.schema.clone(), table_name_str));
+    } else {
+        let position = path.syntax().text_range().start();
+        let search_path = binder.search_path_at(position);
+        for search_schema in search_path {
+            if let Some(symbol_id) = symbols.iter().copied().find(|id| {
+                let symbol = &binder.symbols[*id];
+                symbol.kind == SymbolKind::Table && &symbol.schema == search_schema
+            }) {
+                let symbol = &binder.symbols[symbol_id];
+                return Some((symbol.schema.clone(), table_name_str));
+            }
+        }
+    }
+    None
+}
+
+fn extract_table_name_from_path(path: &ast::Path) -> Option<String> {
+    let segment = path.segment()?;
+    if let Some(name_ref) = segment.name_ref() {
+        return Some(name_ref.syntax().text().to_string());
+    }
+    if let Some(name) = segment.name() {
+        return Some(name.syntax().text().to_string());
+    }
+    None
+}
+
+fn extract_schema_from_path(path: &ast::Path) -> Option<String> {
+    path.qualifier()
+        .and_then(|q| q.segment())
+        .and_then(|s| s.name_ref())
+        .map(|name_ref| name_ref.syntax().text().to_string())
+}

crates/squawk_ide/src/symbols.rs

@@ -1,6 +1,7 @@
 use la_arena::Idx;
 use smol_str::SmolStr;
 use squawk_syntax::SyntaxNodePtr;
+use std::fmt;
 
 #[derive(Clone, Debug, PartialEq, Eq, Hash)]
 pub(crate) struct Name(pub(crate) SmolStr);
@@ -14,6 +15,12 @@ impl Schema {
     }
 }
 
+impl fmt::Display for Schema {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{}", self.0.0)
+    }
+}
+
 impl Name {
     pub(crate) fn new(text: impl Into<SmolStr>) -> Self {
         let text = text.into();