feat: show columns on table hover

crates/pgls_hover/src/hoverables/table.rs

@@ -6,6 +6,8 @@ use pgls_treesitter::TreesitterContext;
 
 use crate::{contextual_priority::ContextualPriority, to_markdown::ToHoverMarkdown};
 
+const MAX_COLUMNS_IN_HOVER: usize = 20;
+
 impl ToHoverMarkdown for Table {
     fn hover_headline<W: Write>(
         &self,
@@ -37,15 +39,61 @@ impl ToHoverMarkdown for Table {
     fn hover_body<W: Write>(
         &self,
         writer: &mut W,
-        _schema_cache: &SchemaCache,
+        schema_cache: &SchemaCache,
     ) -> Result<bool, std::fmt::Error> {
         if let Some(comment) = &self.comment {
             write!(writer, "Comment: '{comment}'")?;
             writeln!(writer)?;
-            Ok(true)
-        } else {
-            Ok(false)
         }
+
+        let mut columns: Vec<_> = schema_cache
+            .columns
+            .iter()
+            .filter(|column| column.schema_name == self.schema && column.table_name == self.name)
+            .collect();
+        columns.sort_by_key(|column| column.number);
+
+        writeln!(writer, "Columns:")?;
+
+        for column in columns.iter().take(MAX_COLUMNS_IN_HOVER) {
+            write!(writer, "- {}: ", column.name)?;
+
+            if let Some(type_name) = &column.type_name {
+                write!(writer, "{type_name}")?;
+
+                if let Some(varchar_length) = column.varchar_length {
+                    write!(writer, "({varchar_length})")?;
+                }
+            } else {
+                write!(writer, "typeid:{}", column.type_id)?;
+            }
+
+            if column.is_nullable {
+                write!(writer, " - nullable")?;
+            } else {
+                write!(writer, " - not null")?;
+            }
+
+            if let Some(default_expr) = column
+                .default_expr
+                .as_deref()
+                .and_then(extract_basic_default_literal)
+            {
+                write!(writer, " - default: {default_expr}")?;
+            }
+
+            writeln!(writer)?;
+        }
+
+        if columns.len() > MAX_COLUMNS_IN_HOVER {
+            writeln!(
+                writer,
+                "... +{} more columns",
+                columns.len() - MAX_COLUMNS_IN_HOVER
+            )?;
+        }
+
+        Ok(true)
     }
 
     fn hover_footer<W: Write>(
@@ -65,6 +113,45 @@ impl ToHoverMarkdown for Table {
     }
 }
 
+// `extract_basic_default_literal` will extract simple default literals for table hover.
+// Example: `'anonymous'::text` -> `anonymous`, `(42)::int8` -> `42`, `now()` -> ignored.
+fn extract_basic_default_literal(default_expr: &str) -> Option<String> {
+    let mut cast_parts = default_expr.split("::");
+    let mut value = cast_parts.next().unwrap_or(default_expr).trim();
+
+    if cast_parts.any(|cast_part| !is_type_cast_fragment(cast_part)) {
+        return None;
+    }
+
+    while value.starts_with('(') && value.ends_with(')') && value.len() > 1 {
+        value = value[1..value.len() - 1].trim();
+    }
+
+    if value.starts_with('\'') && value.ends_with('\'') && value.len() > 1 {
+        value = &value[1..value.len() - 1];
+    }
+
+    let value = value.trim();
+    if value.is_empty() || !contains_only_basic_chars(value) {
+        return None;
+    }
+
+    Some(value.to_string())
+}
+
+fn contains_only_basic_chars(value: &str) -> bool {
+    value
+        .chars()
+        .all(|c| c.is_ascii_alphanumeric() || matches!(c, ' ' | '_' | '-' | '.'))
+}
+
+fn is_type_cast_fragment(value: &str) -> bool {
+    value.trim().chars().all(|c| {
+        c.is_ascii_alphanumeric()
+            || matches!(c, ' ' | '_' | '.' | '"' | '[' | ']' | '(' | ')' | ',')
+    })
+}
+
 impl ContextualPriority for Table {
     fn relevance_score(&self, ctx: &TreesitterContext) -> f32 {
         let mut score = 0.0;
@@ -93,3 +180,42 @@ impl ContextualPriority for Table {
         score
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::extract_basic_default_literal;
+
+    #[test]
+    fn extracts_basic_defaults_with_optional_casts() {
+        assert_eq!(
+            extract_basic_default_literal("'anonymous'::text"),
+            Some("anonymous".to_string())
+        );
+        assert_eq!(
+            extract_basic_default_literal("(42)::int8"),
+            Some("42".to_string())
+        );
+        assert_eq!(
+            extract_basic_default_literal("NULL::character varying"),
+            Some("NULL".to_string())
+        );
+        assert_eq!(
+            extract_basic_default_literal("false::boolean"),
+            Some("false".to_string())
+        );
+    }
+
+    #[test]
+    fn ignores_non_basic_defaults() {
+        assert_eq!(
+            extract_basic_default_literal("nextval('users_id_seq'::regclass)"),
+            None
+        );
+        assert_eq!(extract_basic_default_literal("now()"), None);
+        assert_eq!(
+            extract_basic_default_literal("'a'::text || 'b'::text"),
+            None
+        );
+        assert_eq!(extract_basic_default_literal("'with@symbol'::text"), None);
+    }
+}

crates/pgls_hover/tests/hover_integration_tests.rs

@@ -200,6 +200,49 @@ async fn test_table_hover_works(test_db: PgPool) {
     test_hover_at_cursor("table_hover", query, Some(setup), &test_db).await;
 }
 
+#[sqlx::test(migrator = "pgls_test_utils::MIGRATIONS")]
+async fn test_table_hover_select_star(test_db: PgPool) {
+    let setup = r#"
+        create table users (
+            id serial primary key,
+            email varchar(255) not null
+        );
+    "#;
+
+    let query = format!(
+        "select * from use{}rs",
+        QueryWithCursorPosition::cursor_marker()
+    );
+
+    test_hover_at_cursor("table_hover_select_star", query, Some(setup), &test_db).await;
+}
+
+#[sqlx::test(migrator = "pgls_test_utils::MIGRATIONS")]
+async fn test_table_hover_shows_nullable_and_basic_defaults(test_db: PgPool) {
+    let setup = r#"
+        create table users (
+            id serial primary key,
+            name text default 'anonymous',
+            score int default 0,
+            enabled bool default false,
+            created_at timestamptz default now()
+        );
+    "#;
+
+    let query = format!(
+        "select * from use{}rs",
+        QueryWithCursorPosition::cursor_marker()
+    );
+
+    test_hover_at_cursor(
+        "table_hover_nullable_and_basic_defaults",
+        query,
+        Some(setup),
+        &test_db,
+    )
+    .await;
+}
+
 #[sqlx::test(migrator = "pgls_test_utils::MIGRATIONS")]
 async fn test_no_hover_on_keyword(test_db: PgPool) {
     let setup = r#"

crates/pgls_hover/tests/snapshots/create_policy.snap

@@ -1,5 +1,5 @@
 ---
-source: crates/pgt_hover/tests/hover_integration_tests.rs
+source: crates/pgls_hover/tests/hover_integration_tests.rs
 expression: snapshot
 ---
 # Input
@@ -11,6 +11,9 @@ create policy "my cool pol" on users for all to public with check (true);
 # Hover Results
 ### `public.users` - 🔓 RLS disabled  
 ```plain  
+Columns:
+- id: int4 - not null
+- name: text - nullable
 
 ```  
 ---    

crates/pgls_hover/tests/snapshots/grant_select.snap

@@ -1,5 +1,5 @@
 ---
-source: crates/pgt_hover/tests/hover_integration_tests.rs
+source: crates/pgls_hover/tests/hover_integration_tests.rs
 expression: snapshot
 ---
 # Input
@@ -11,6 +11,9 @@ grant select on users to public;
 # Hover Results
 ### `public.users` - 🔓 RLS disabled  
 ```plain  
+Columns:
+- id: int4 - not null
+- name: text - nullable
 
 ```  
 ---    

crates/pgls_hover/tests/snapshots/revoke_select.snap

@@ -1,5 +1,5 @@
 ---
-source: crates/pgt_hover/tests/hover_integration_tests.rs
+source: crates/pgls_hover/tests/hover_integration_tests.rs
 expression: snapshot
 ---
 # Input
@@ -11,6 +11,9 @@ revoke select on users from public;
 # Hover Results
 ### `public.users` - 🔓 RLS disabled  
 ```plain  
+Columns:
+- id: int4 - not null
+- name: text - nullable
 
 ```  
 ---    

crates/pgls_hover/tests/snapshots/table_hover.snap

@@ -1,5 +1,5 @@
 ---
-source: crates/pgt_hover/tests/hover_integration_tests.rs
+source: crates/pgls_hover/tests/hover_integration_tests.rs
 expression: snapshot
 ---
 # Input
@@ -11,6 +11,9 @@ select id from users
 # Hover Results
 ### `public.users` - 🔓 RLS disabled  
 ```plain  
+Columns:
+- id: int4 - not null
+- email: varchar(255) - not null
 
 ```  
 ---    

crates/pgls_hover/tests/snapshots/table_hover_nullable_and_basic_defaults.snap

@@ -0,0 +1,26 @@
+---
+source: crates/pgls_hover/tests/hover_integration_tests.rs
+expression: snapshot
+---
+# Input
+```sql
+select * from users
+                 ↑ hovered here
+```
+
+# Hover Results
+### `public.users` - 🔓 RLS disabled  
+```plain  
+Columns:
+- id: int4 - not null
+- name: text - nullable - default: anonymous
+- score: int4 - nullable - default: 0
+- enabled: bool - nullable - default: false
+- created_at: timestamptz - nullable
+
+```  
+---    
+```plain  
+
+~0 rows, ~0 dead rows, 16.38 kB  
+```

crates/pgls_hover/tests/snapshots/table_hover_quoted_schema.snap

@@ -1,5 +1,5 @@
 ---
-source: crates/pgt_hover/tests/hover_integration_tests.rs
+source: crates/pgls_hover/tests/hover_integration_tests.rs
 expression: snapshot
 ---
 # Input
@@ -11,6 +11,9 @@ select * from "auth".users
 # Hover Results
 ### `auth.users` - 🔓 RLS disabled  
 ```plain  
+Columns:
+- id: int4 - not null
+- email: varchar(255) - not null
 
 ```  
 ---    

crates/pgls_hover/tests/snapshots/table_hover_quoted_table_name.snap

@@ -1,5 +1,5 @@
 ---
-source: crates/pgt_hover/tests/hover_integration_tests.rs
+source: crates/pgls_hover/tests/hover_integration_tests.rs
 expression: snapshot
 ---
 # Input
@@ -11,6 +11,9 @@ select * from "auth"."users"
 # Hover Results
 ### `auth.users` - 🔓 RLS disabled  
 ```plain  
+Columns:
+- id: int4 - not null
+- email: varchar(255) - not null
 
 ```  
 ---    

crates/pgls_hover/tests/snapshots/table_hover_select_star.snap

@@ -0,0 +1,23 @@
+---
+source: crates/pgls_hover/tests/hover_integration_tests.rs
+expression: snapshot
+---
+# Input
+```sql
+select * from users
+                 ↑ hovered here
+```
+
+# Hover Results
+### `public.users` - 🔓 RLS disabled  
+```plain  
+Columns:
+- id: int4 - not null
+- email: varchar(255) - not null
+
+```  
+---    
+```plain  
+
+~0 rows, ~0 dead rows, 8.19 kB  
+```