Feature 1827 - query CLI line continuation (#1968)

Cargo.lock

@@ -3565,6 +3565,7 @@ dependencies = [
  "memchr",
  "nix",
  "radix_trie",
+ "rustyline-derive",
  "scopeguard",
  "unicode-segmentation",
  "unicode-width",
@@ -3572,6 +3573,17 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "rustyline-derive"
+version = "0.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8218eaf5d960e3c478a1b0f129fa888dd3d8d22eb3de097e9af14c1ab4438024"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 1.0.109",
+]
+
 [[package]]
 name = "ryu"
 version = "1.0.13"

Cargo.toml

@@ -43,7 +43,7 @@ opentelemetry = { version = "0.18", features = ["rt-tokio"] }
 opentelemetry-otlp = "0.11.0"
 rand = "0.8.5"
 reqwest = { version = "0.11.16", features = ["blocking"] }
-rustyline = "11.0.0"
+rustyline = { version = "11.0.0", features = ["derive"] }
 serde = { version = "1.0.160", features = ["derive"] }
 serde_cbor = "0.11.2"
 serde_pack = { version = "1.1.1", package = "rmp-serde" }

Makefile

@@ -34,7 +34,7 @@ serve:
 
 .PHONY: sql
 sql:
-	cargo run $(DEV_FEATURES) -- sql --conn ws://0.0.0.0:8000 --user root --pass root --ns test --db test --pretty
+	cargo run $(DEV_FEATURES) -- sql --conn ws://0.0.0.0:8000 --user root --pass root --ns test --db test --multi --pretty
 
 .PHONY: quick
 quick:

src/cli/mod.rs

@@ -472,6 +472,13 @@ pub fn init() -> ExitCode {
 					.default_value("root")
 					.help("Database authentication username to use when connecting"),
 			)
+			.arg(
+				Arg::new("multi")
+					.long("multi")
+					.required(false)
+					.takes_value(false)
+					.help("Whether omitting semicolon causes a newline"),
+			)
 			.arg(
 				Arg::new("pass")
 					.short('p')

src/cli/sql.rs

@@ -1,14 +1,12 @@
 use crate::err::Error;
 use rustyline::error::ReadlineError;
-use rustyline::DefaultEditor;
+use rustyline::validate::{ValidationContext, ValidationResult, Validator};
+use rustyline::{Completer, Editor, Helper, Highlighter, Hinter};
 use surrealdb::engine::any::connect;
 use surrealdb::error::Api as ApiError;
 use surrealdb::opt::auth::Root;
-use surrealdb::sql;
-use surrealdb::sql::Statement;
-use surrealdb::sql::Value;
-use surrealdb::Error as SurrealError;
-use surrealdb::Response;
+use surrealdb::sql::{self, Statement, Value};
+use surrealdb::{Error as SurrealError, Response};
 
 #[tokio::main]
 pub async fn init(matches: &clap::ArgMatches) -> Result<(), Error> {
@@ -39,7 +37,11 @@ pub async fn init(matches: &clap::ArgMatches) -> Result<(), Error> {
 		}
 	}
 	// Create a new terminal REPL
-	let mut rl = DefaultEditor::new().unwrap();
+	let mut rl = Editor::new().unwrap();
+	// Set custom input validation
+	rl.set_helper(Some(InputValidator {
+		multi: matches.is_present("multi"),
+	}));
 	// Load the command-line history
 	let _ = rl.load_history("history.txt");
 	// Configure the prompt
@@ -70,12 +72,12 @@ pub async fn init(matches: &clap::ArgMatches) -> Result<(), Error> {
 			},
 			(None, None) => {}
 		}
-		// Prompt the user to input SQL
-		let readline = rl.readline(&prompt);
-		// Check the user input
-		match readline {
+
+		// Prompt the user to input SQL and check the input.
+		let line = match rl.readline(&prompt) {
 			// The user typed a query
 			Ok(line) => {
+				let line = filter_line_continuations(&line);
 				// Ignore all empty lines
 				if line.is_empty() {
 					continue;
@@ -84,6 +86,19 @@ pub async fn init(matches: &clap::ArgMatches) -> Result<(), Error> {
 				if let Err(e) = rl.add_history_entry(line.as_str()) {
 					eprintln!("{e}");
 				}
+				line
+			}
+			// The user typed CTRL-C or CTRL-D
+			Err(ReadlineError::Interrupted | ReadlineError::Eof) => {
+				break;
+			}
+			// There was en error
+			Err(e) => {
+				eprintln!("Error: {e:?}");
+				break;
+			}
+		};
+
 		// Complete the request
 		match sql::parse(&line) {
 			Ok(query) => {
@@ -121,21 +136,6 @@ pub async fn init(matches: &clap::ArgMatches) -> Result<(), Error> {
 			}
 		}
 	}
-			// The user types CTRL-C
-			Err(ReadlineError::Interrupted) => {
-				break;
-			}
-			// The user typed CTRL-D
-			Err(ReadlineError::Eof) => {
-				break;
-			}
-			// There was en error
-			Err(e) => {
-				eprintln!("Error: {e:?}");
-				break;
-			}
-		}
-	}
 	// Save the inputs to the history
 	let _ = rl.save_history("history.txt");
 	// Everything OK
@@ -165,3 +165,31 @@ fn process(pretty: bool, res: surrealdb::Result<Response>) -> Result<String, Err
 		true => format!("{value:#}"),
 	})
 }
+
+#[derive(Completer, Helper, Highlighter, Hinter)]
+struct InputValidator {
+	/// If omitting semicolon causes newline.
+	multi: bool,
+}
+
+impl Validator for InputValidator {
+	fn validate(&self, ctx: &mut ValidationContext) -> rustyline::Result<ValidationResult> {
+		use ValidationResult::{Incomplete, Invalid, Valid};
+		let input = filter_line_continuations(ctx.input());
+		let result = if (self.multi && !input.trim().ends_with(';'))
+			|| input.ends_with('\\')
+			|| input.is_empty()
+		{
+			Incomplete
+		} else if let Err(e) = sql::parse(&input) {
+			Invalid(Some(format!(" --< {e}")))
+		} else {
+			Valid(None)
+		};
+		Ok(result)
+	}
+}
+
+fn filter_line_continuations(line: &str) -> String {
+	line.replace("\\\n", "").replace("\\\r\n", "")
+}