From 60b78b3566d10dd7055fa7ff0e0da970307c34c6 Mon Sep 17 00:00:00 2001
From: Diego Reis <reisdiego144@gmail.com>
Date: Sun, 25 May 2025 15:56:28 -0300
Subject: [PATCH] bind/js: Partially implements pragma

Some pragmas may return more than one value, which would
break the current logic. So this cause should be handled in the future
---
 .../__test__/better-sqlite3.spec.mjs          |  6 ++
 bindings/javascript/__test__/limbo.spec.mjs   |  6 ++
 bindings/javascript/src/lib.rs                | 57 ++++++++++++++++---
 bindings/javascript/wrapper.js                | 10 +++-
 4 files changed, 70 insertions(+), 9 deletions(-)

diff --git a/bindings/javascript/__test__/better-sqlite3.spec.mjs b/bindings/javascript/__test__/better-sqlite3.spec.mjs
index aefe0aa92..94f3570dd 100644
--- a/bindings/javascript/__test__/better-sqlite3.spec.mjs
+++ b/bindings/javascript/__test__/better-sqlite3.spec.mjs
@@ -52,6 +52,12 @@ test("Empty prepared statement should throw", async (t) => {
   );
 });
 
+test("Test pragma", async (t) => {
+  const [db] = await connect(":memory:");
+  t.deepEqual(typeof db.pragma("cache_size")[0].cache_size, "number");
+  t.deepEqual(typeof db.pragma("cache_size", { simple: true }), "number");
+});
+
 const connect = async (path) => {
   const db = new Database(path);
   return [db];
diff --git a/bindings/javascript/__test__/limbo.spec.mjs b/bindings/javascript/__test__/limbo.spec.mjs
index c4c4c6a78..73e5412ba 100644
--- a/bindings/javascript/__test__/limbo.spec.mjs
+++ b/bindings/javascript/__test__/limbo.spec.mjs
@@ -65,6 +65,12 @@ test("Empty prepared statement should throw", async (t) => {
   );
 });
 
+test("Test pragma", async (t) => {
+  const [db] = await connect(":memory:");
+  t.deepEqual(typeof db.pragma("cache_size")[0].cache_size, "number");
+  t.deepEqual(typeof db.pragma("cache_size", { simple: true }), "number");
+});
+
 const connect = async (path) => {
   const db = new Database(path);
   return [db];
diff --git a/bindings/javascript/src/lib.rs b/bindings/javascript/src/lib.rs
index 6cb3eab2f..a06d6500d 100644
--- a/bindings/javascript/src/lib.rs
+++ b/bindings/javascript/src/lib.rs
@@ -83,11 +83,6 @@ impl Database {
         Ok(Statement::new(RefCell::new(stmt), self.clone(), sql))
     }
 
-    #[napi]
-    pub fn pragma(&self) {
-        todo!()
-    }
-
     #[napi]
     pub fn backup(&self) {
         todo!()
@@ -128,6 +123,46 @@ impl Database {
         self.conn.close().map_err(into_napi_error)?;
         Ok(())
     }
+
+    // We assume that every pragma only returns one result, which isn't
+    // true.
+    #[napi]
+    pub fn pragma(&self, env: Env, pragma: String, simple: bool) -> napi::Result<JsUnknown> {
+        let stmt = self.prepare(pragma.clone())?;
+        let mut stmt = stmt.inner.borrow_mut();
+        let pragma_name = pragma
+            .split("PRAGMA")
+            .filter(|s| !s.trim().is_empty())
+            .next()
+            .map(str::trim)
+            .unwrap();
+        let mut results = env.create_empty_array()?;
+
+        let step = stmt.step().map_err(into_napi_error)?;
+        match step {
+            limbo_core::StepResult::Row => {
+                let row = stmt.row().unwrap();
+                let mut obj = env.create_object()?;
+                for (_, value) in row.get_values().enumerate() {
+                    let js_value = to_js_value(&env, value)?;
+
+                    if simple {
+                        return Ok(js_value);
+                    }
+
+                    obj.set_named_property(&pragma_name, js_value)?;
+                }
+
+                results.set_element(0, obj)?;
+                Ok(results.into_unknown())
+            }
+            limbo_core::StepResult::Done => Ok(env.get_undefined()?.into_unknown()),
+            limbo_core::StepResult::IO => todo!(),
+            limbo_core::StepResult::Interrupt | limbo_core::StepResult::Busy => Err(
+                napi::Error::new(napi::Status::GenericFailure, format!("{:?}", step)),
+            ),
+        }
+    }
 }
 
 // TODO: Add the (parent) 'database' property
@@ -142,6 +177,8 @@ pub struct Statement {
     // pub busy: bool,
     #[napi(writable = false)]
     pub source: String,
+
+    toggle: bool,
     database: Database,
     inner: Rc<RefCell<limbo_core::Statement>>,
 }
@@ -153,6 +190,7 @@ impl Statement {
             inner: Rc::new(inner),
             database,
             source,
+            toggle: false,
         }
     }
 
@@ -278,9 +316,14 @@ impl Statement {
     }
 
     #[napi]
-    pub fn pluck() {
-        todo!()
+    pub fn pluck(&mut self, toggle: Option<bool>) {
+        if let Some(false) = toggle {
+            self.toggle = false;
+        }
+
+        self.toggle = true;
     }
+
     #[napi]
     pub fn expand() {
         todo!()
diff --git a/bindings/javascript/wrapper.js b/bindings/javascript/wrapper.js
index f9584835f..22492bd63 100644
--- a/bindings/javascript/wrapper.js
+++ b/bindings/javascript/wrapper.js
@@ -77,13 +77,19 @@ class Database {
 
   pragma(source, options) {
     if (options == null) options = {};
+
     if (typeof source !== "string")
       throw new TypeError("Expected first argument to be a string");
+
     if (typeof options !== "object")
       throw new TypeError("Expected second argument to be an options object");
+
     const simple = options["simple"];
-    const stmt = this.prepare(`PRAGMA ${source}`, this, true);
-    return simple ? stmt.pluck().get() : stmt.all();
+    const pragma = `PRAGMA ${source}`;
+
+    return simple
+      ? this.db.pragma(pragma, true)
+      : this.db.pragma(pragma, false);
   }
 
   backup(filename, options) {