feat: basic hover (#463)

Author: juleswritescode

Cargo.lock

@@ -72,6 +72,7 @@ pgt_diagnostics_categories = { path = "./crates/pgt_diagnostics_categories", ver
 pgt_diagnostics_macros     = { path = "./crates/pgt_diagnostics_macros", version = "0.0.0" }
 pgt_flags                  = { path = "./crates/pgt_flags", version = "0.0.0" }
 pgt_fs                     = { path = "./crates/pgt_fs", version = "0.0.0" }
+pgt_hover                  = { path = "./crates/pgt_hover", version = "0.0.0" }
 pgt_lexer                  = { path = "./crates/pgt_lexer", version = "0.0.0" }
 pgt_lexer_codegen          = { path = "./crates/pgt_lexer_codegen", version = "0.0.0" }
 pgt_lsp                    = { path = "./crates/pgt_lsp", version = "0.0.0" }

Cargo.toml

@@ -0,0 +1,36 @@
+[package]
+authors.workspace    = true
+categories.workspace = true
+description          = "<DESCRIPTION>"
+edition.workspace    = true
+homepage.workspace   = true
+keywords.workspace   = true
+license.workspace    = true
+name                 = "pgt_hover"
+repository.workspace = true
+version              = "0.0.0"
+
+
+[dependencies]
+humansize                  = { version = "2.1.3" }
+pgt_query.workspace        = true
+pgt_schema_cache.workspace = true
+pgt_text_size.workspace    = true
+pgt_treesitter.workspace   = true
+schemars                   = { workspace = true, optional = true }
+serde                      = { workspace = true, features = ["derive"] }
+serde_json                 = { workspace = true }
+sqlx.workspace             = true
+tokio                      = { version = "1.41.1", features = ["full"] }
+tracing                    = { workspace = true }
+tree-sitter.workspace      = true
+tree_sitter_sql.workspace  = true
+
+[dev-dependencies]
+pgt_test_utils.workspace = true
+
+[lib]
+doctest = false
+
+[features]
+schema = ["dep:schemars"]

crates/pgt_hover/Cargo.toml

@@ -0,0 +1,50 @@
+use pgt_text_size::TextSize;
+use pgt_treesitter::TreeSitterContextParams;
+
+#[derive(Debug)]
+pub(crate) enum NodeIdentification {
+    Name(String),
+    SchemaAndName((String, String)),
+    #[allow(unused)]
+    SchemaAndTableAndName((String, String, String)),
+}
+
+#[allow(unused)]
+#[derive(Debug)]
+pub(crate) enum HoveredNode {
+    Schema(NodeIdentification),
+    Table(NodeIdentification),
+    Function(NodeIdentification),
+    Column(NodeIdentification),
+    Policy(NodeIdentification),
+    Trigger(NodeIdentification),
+    Role(NodeIdentification),
+}
+
+impl HoveredNode {
+    pub(crate) fn get(position: TextSize, text: &str, tree: &tree_sitter::Tree) -> Option<Self> {
+        let ctx = pgt_treesitter::context::TreesitterContext::new(TreeSitterContextParams {
+            position,
+            text,
+            tree,
+        });
+
+        let node_content = ctx.get_node_under_cursor_content()?;
+
+        let under_node = ctx.node_under_cursor.as_ref()?;
+
+        match under_node.kind() {
+            "identifier" if ctx.parent_matches_one_of_kind(&["object_reference", "relation"]) => {
+                if let Some(schema) = ctx.schema_or_alias_name {
+                    Some(HoveredNode::Table(NodeIdentification::SchemaAndName((
+                        schema,
+                        node_content,
+                    ))))
+                } else {
+                    Some(HoveredNode::Table(NodeIdentification::Name(node_content)))
+                }
+            }
+            _ => None,
+        }
+    }
+}

crates/pgt_hover/src/hovered_node.rs

@@ -0,0 +1,47 @@
+use pgt_schema_cache::SchemaCache;
+use pgt_text_size::TextSize;
+
+use crate::{hovered_node::HoveredNode, to_markdown::ToHoverMarkdown};
+
+mod hovered_node;
+mod to_markdown;
+
+pub struct OnHoverParams<'a> {
+    pub position: TextSize,
+    pub schema_cache: &'a SchemaCache,
+    pub stmt_sql: &'a str,
+    pub ast: Option<&'a pgt_query::NodeEnum>,
+    pub ts_tree: &'a tree_sitter::Tree,
+}
+
+pub fn on_hover(params: OnHoverParams) -> Vec<String> {
+    if let Some(hovered_node) = HoveredNode::get(params.position, params.stmt_sql, params.ts_tree) {
+        match hovered_node {
+            HoveredNode::Table(node_identification) => {
+                let table = match node_identification {
+                    hovered_node::NodeIdentification::Name(n) => {
+                        params.schema_cache.find_table(n.as_str(), None)
+                    }
+                    hovered_node::NodeIdentification::SchemaAndName((s, n)) => {
+                        params.schema_cache.find_table(n.as_str(), Some(s.as_str()))
+                    }
+                    hovered_node::NodeIdentification::SchemaAndTableAndName(_) => None,
+                };
+
+                table
+                    .map(|t| {
+                        let mut markdown = String::new();
+                        match t.to_hover_markdown(&mut markdown) {
+                            Ok(_) => vec![markdown],
+                            Err(_) => vec![],
+                        }
+                    })
+                    .unwrap_or(vec![])
+            }
+
+            _ => todo!(),
+        }
+    } else {
+        Default::default()
+    }
+}

crates/pgt_hover/src/lib.rs

@@ -0,0 +1,90 @@
+use std::fmt::Write;
+
+use humansize::DECIMAL;
+
+pub(crate) trait ToHoverMarkdown {
+    fn to_hover_markdown<W: Write>(&self, writer: &mut W) -> Result<(), std::fmt::Error>;
+}
+
+impl ToHoverMarkdown for pgt_schema_cache::Table {
+    fn to_hover_markdown<W: Write>(&self, writer: &mut W) -> Result<(), std::fmt::Error> {
+        HeadlineWriter::for_table(writer, self)?;
+        BodyWriter::for_table(writer, self)?;
+        FooterWriter::for_table(writer, self)?;
+
+        Ok(())
+    }
+}
+
+struct HeadlineWriter;
+
+impl HeadlineWriter {
+    fn for_table<W: Write>(
+        writer: &mut W,
+        table: &pgt_schema_cache::Table,
+    ) -> Result<(), std::fmt::Error> {
+        let table_kind = match table.table_kind {
+            pgt_schema_cache::TableKind::View => " (View)",
+            pgt_schema_cache::TableKind::MaterializedView => " (M.View)",
+            pgt_schema_cache::TableKind::Partitioned => " (Partitioned)",
+            pgt_schema_cache::TableKind::Ordinary => "",
+        };
+
+        let locked_txt = if table.rls_enabled {
+            " - 🔒 RLS enabled"
+        } else {
+            " - 🔓 RLS disabled"
+        };
+
+        write!(
+            writer,
+            "### {}.{}{}{}",
+            table.schema, table.name, table_kind, locked_txt
+        )?;
+
+        markdown_newline(writer)?;
+
+        Ok(())
+    }
+}
+
+struct BodyWriter;
+
+impl BodyWriter {
+    fn for_table<W: Write>(
+        writer: &mut W,
+        table: &pgt_schema_cache::Table,
+    ) -> Result<(), std::fmt::Error> {
+        if let Some(c) = table.comment.as_ref() {
+            write!(writer, "{}", c)?;
+            markdown_newline(writer)?;
+        }
+
+        Ok(())
+    }
+}
+
+struct FooterWriter;
+
+impl FooterWriter {
+    fn for_table<W: Write>(
+        writer: &mut W,
+        table: &pgt_schema_cache::Table,
+    ) -> Result<(), std::fmt::Error> {
+        write!(
+            writer,
+            "~{} rows, ~{} dead rows, {}",
+            table.live_rows_estimate,
+            table.dead_rows_estimate,
+            humansize::format_size(table.bytes as u64, DECIMAL)
+        )?;
+
+        Ok(())
+    }
+}
+
+fn markdown_newline<W: Write>(writer: &mut W) -> Result<(), std::fmt::Error> {
+    write!(writer, "  ")?;
+    writeln!(writer)?;
+    Ok(())
+}

crates/pgt_hover/src/to_markdown.rs

@@ -3,9 +3,10 @@ use crate::handlers::code_actions::command_id;
 use pgt_workspace::features::code_actions::CommandActionCategory;
 use strum::IntoEnumIterator;
 use tower_lsp::lsp_types::{
-    ClientCapabilities, CompletionOptions, ExecuteCommandOptions, PositionEncodingKind,
-    SaveOptions, ServerCapabilities, TextDocumentSyncCapability, TextDocumentSyncKind,
-    TextDocumentSyncOptions, TextDocumentSyncSaveOptions, WorkDoneProgressOptions,
+    ClientCapabilities, CompletionOptions, ExecuteCommandOptions, HoverProviderCapability,
+    PositionEncodingKind, SaveOptions, ServerCapabilities, TextDocumentSyncCapability,
+    TextDocumentSyncKind, TextDocumentSyncOptions, TextDocumentSyncSaveOptions,
+    WorkDoneProgressOptions,
 };
 
 /// The capabilities to send from server as part of [`InitializeResult`]
@@ -62,6 +63,7 @@ pub(crate) fn server_capabilities(capabilities: &ClientCapabilities) -> ServerCa
             true,
         )),
         rename_provider: None,
+        hover_provider: Some(HoverProviderCapability::Simple(true)),
         ..Default::default()
     }
 }

crates/pgt_lsp/src/capabilities.rs

@@ -1,3 +1,4 @@
 pub(crate) mod code_actions;
 pub(crate) mod completions;
+pub(crate) mod hover;
 pub(crate) mod text_document;

crates/pgt_lsp/src/handlers.rs

@@ -0,0 +1,42 @@
+use pgt_workspace::{WorkspaceError, features::on_hover::OnHoverParams};
+use tower_lsp::lsp_types::{self, MarkedString, MarkupContent};
+
+use crate::{adapters::get_cursor_position, diagnostics::LspError, session::Session};
+
+pub(crate) fn on_hover(
+    session: &Session,
+    params: lsp_types::HoverParams,
+) -> Result<lsp_types::HoverContents, LspError> {
+    let url = params.text_document_position_params.text_document.uri;
+    let position = params.text_document_position_params.position;
+    let path = session.file_path(&url)?;
+
+    match session.workspace.on_hover(OnHoverParams {
+        path,
+        position: get_cursor_position(session, &url, position)?,
+    }) {
+        Ok(result) => {
+            tracing::debug!("Found hover items: {:#?}", result);
+
+            Ok(lsp_types::HoverContents::Array(
+                result
+                    .into_iter()
+                    .map(MarkedString::from_markdown)
+                    .collect(),
+            ))
+        }
+
+        Err(e) => match e {
+            WorkspaceError::DatabaseConnectionError(_) => {
+                Ok(lsp_types::HoverContents::Markup(MarkupContent {
+                    kind: lsp_types::MarkupKind::PlainText,
+                    value: "Cannot connect to database.".into(),
+                }))
+            }
+            _ => {
+                tracing::error!("Received an error: {:#?}", e);
+                Err(e.into())
+            }
+        },
+    }
+}

crates/pgt_lsp/src/handlers/hover.rs

@@ -265,6 +265,17 @@ impl LanguageServer for LSPServer {
         }
     }
 
+    #[tracing::instrument(level = "trace", skip_all)]
+    async fn hover(&self, params: HoverParams) -> LspResult<Option<Hover>> {
+        match handlers::hover::on_hover(&self.session, params) {
+            Ok(result) => LspResult::Ok(Some(Hover {
+                contents: result,
+                range: None,
+            })),
+            Err(e) => LspResult::Err(into_lsp_error(e)),
+        }
+    }
+
     #[tracing::instrument(level = "trace", skip_all)]
     async fn completion(&self, params: CompletionParams) -> LspResult<Option<CompletionResponse>> {
         match handlers::completions::get_completions(&self.session, params) {