Let yaak-models compile for wasm32-unknown-unknown (#556)

crates/common/yaak-database/Cargo.toml

@@ -9,12 +9,20 @@ chrono = { version = "0.4.38", features = ["serde"] }
 include_dir = "0.7"
 log = { workspace = true }
 nanoid = "0.4.0"
-r2d2 = "0.8.10"
-r2d2_sqlite = { version = "0.25.0" }
-rusqlite = { version = "0.32.1", features = ["bundled", "chrono"] }
-sea-query = { version = "0.32.1", features = ["with-chrono", "attr"] }
-sea-query-rusqlite = { version = "0.7.0", features = ["with-chrono"] }
+rusqlite = { version = "0.38", features = ["bundled", "chrono"] }
+sea-query-rusqlite = { version = "0.8.0", features = ["with-chrono"] }
+sea-query = { version = "1.0", features = ["with-chrono", "attr"] }
 serde = { workspace = true, features = ["derive"] }
 serde_json = { workspace = true }
 thiserror = { workspace = true }
 ts-rs = { workspace = true }
+
+[target.'cfg(not(target_arch = "wasm32"))'.dependencies]
+r2d2 = "0.8.10"
+r2d2_sqlite = { version = "0.32" }
+
+# nanoid pulls getrandom, which needs to be told how to reach the browser's
+# CSPRNG on wasm32-unknown-unknown. Native targets are unaffected.
+[target.'cfg(target_arch = "wasm32")'.dependencies]
+getrandom = { version = "0.2", features = ["js"] }
+uuid = { version = "1", features = ["js"] }

crates/common/yaak-database/src/connection_or_tx.rs

@@ -1,9 +1,8 @@
-use r2d2::PooledConnection;
-use r2d2_sqlite::SqliteConnectionManager;
+use crate::pool::SqliteConn;
 use rusqlite::{Connection, Statement, ToSql, Transaction};
 
 pub enum ConnectionOrTx<'a> {
-    Connection(PooledConnection<SqliteConnectionManager>),
+    Connection(SqliteConn),
     Transaction(&'a Transaction<'a>),
 }
 

crates/common/yaak-database/src/db_context.rs

@@ -3,6 +3,7 @@ use crate::error::Error::ModelNotFound;
 use crate::error::Result;
 use crate::traits::UpsertModelInfo;
 use crate::update_source::UpdateSource;
+use sea_query::ExprTrait;
 use sea_query::{
     Asterisk, Expr, Func, IntoColumnRef, IntoIden, OnConflict, Query, SimpleExpr,
     SqliteQueryBuilder,

crates/common/yaak-database/src/error.rs

@@ -7,7 +7,7 @@ pub enum Error {
     SqlError(#[from] rusqlite::Error),
 
     #[error("SQL Pool error: {0}")]
-    SqlPoolError(#[from] r2d2::Error),
+    SqlPoolError(#[from] crate::pool::PoolError),
 
     #[error("Database error: {0}")]
     Database(String),

crates/common/yaak-database/src/lib.rs

@@ -2,6 +2,7 @@ pub mod connection_or_tx;
 pub mod db_context;
 pub mod error;
 pub mod migrate;
+pub mod pool;
 pub mod traits;
 pub mod update_source;
 pub mod util;
@@ -11,13 +12,15 @@ pub use connection_or_tx::ConnectionOrTx;
 pub use db_context::DbContext;
 pub use error::{Error, Result};
 pub use migrate::run_migrations;
+pub use pool::{PoolError, SqliteConn, SqlitePool};
 pub use traits::{UpsertModelInfo, upsert_date};
 pub use update_source::{ModelChangeEvent, UpdateSource};
 pub use util::{generate_id, generate_id_of_length, generate_prefixed_id};
 
-// Re-export pool types that consumers will need
+// Re-export types that consumers will need
+#[cfg(not(target_arch = "wasm32"))]
 pub use r2d2;
+#[cfg(not(target_arch = "wasm32"))]
 pub use r2d2_sqlite;
 pub use rusqlite;
 pub use sea_query;
-pub use sea_query_rusqlite;

crates/common/yaak-database/src/migrate.rs

@@ -1,8 +1,7 @@
 use crate::error::Result;
+use crate::pool::SqlitePool;
 use include_dir::Dir;
 use log::{debug, info};
-use r2d2::Pool;
-use r2d2_sqlite::SqliteConnectionManager;
 use rusqlite::{OptionalExtension, params};
 
 const TRACKING_TABLE: &str = "_sqlx_migrations";
@@ -11,7 +10,7 @@ const TRACKING_TABLE: &str = "_sqlx_migrations";
 ///
 /// Migrations are sorted by filename (use timestamp prefixes like `00000001_init.sql`).
 /// Applied migrations are tracked in `_sqlx_migrations`.
-pub fn run_migrations(pool: &Pool<SqliteConnectionManager>, dir: &Dir<'_>) -> Result<()> {
+pub fn run_migrations(pool: &SqlitePool, dir: &Dir<'_>) -> Result<()> {
     info!("Running migrations");
 
     // Create tracking table

crates/common/yaak-database/src/pool.rs

@@ -0,0 +1,80 @@
+//! Where connections come from.
+//!
+//! Every query in the model layer asks a pool for a connection, uses it, and
+//! hands it back. That is the whole contract, and it is the one place the
+//! desktop and the browser genuinely differ: the desktop has threads and wants
+//! an r2d2 pool; a browser tab has one thread, no way to spawn another, and one
+//! connection is exactly enough. Everything above this module is identical on
+//! both.
+//!
+//! On native targets `SqlitePool` *is* `r2d2::Pool` — a type alias, so nothing
+//! that already builds pools changes. On wasm it is one connection that every
+//! `get()` hands out a shared handle to.
+//!
+//! A `SqliteConn` only ever derefs immutably. The code above this layer opens
+//! transactions with [`rusqlite::Transaction::new_unchecked`], which takes
+//! `&Connection`; the `&mut` that `Connection::transaction` demands is a
+//! compile-time guard against nesting a transaction on one connection, and it
+//! is what would have forced the wasm pool to lend its connection exclusively.
+//! The model layer nests connections freely — a helper that already holds one
+//! calls another that asks for its own — so an exclusive lend would panic on
+//! the second ask. Sharing the handle instead makes nested *reads* work the way
+//! they do on the desktop; nested *write transactions* fail on both, only
+//! differently (here SQLite refuses the inner `BEGIN`; natively the inner
+//! connection blocks on `busy_timeout` and then fails).
+
+#[cfg(not(target_arch = "wasm32"))]
+mod imp {
+    use r2d2_sqlite::SqliteConnectionManager;
+
+    pub type SqlitePool = r2d2::Pool<SqliteConnectionManager>;
+    pub type SqliteConn = r2d2::PooledConnection<SqliteConnectionManager>;
+    pub type PoolError = r2d2::Error;
+}
+
+#[cfg(target_arch = "wasm32")]
+mod imp {
+    use rusqlite::Connection;
+    use std::ops::Deref;
+    use std::rc::Rc;
+
+    /// One connection, shared by everyone who asks.
+    ///
+    /// `Rc` rather than `Arc` because a `Connection` is `!Sync`, so wrapping
+    /// it in an `Arc` would buy no `Send`/`Sync` anyway — and there is one
+    /// thread here to be honest about.
+    #[derive(Clone, Debug)]
+    pub struct SqlitePool {
+        conn: Rc<Connection>,
+    }
+
+    impl SqlitePool {
+        pub fn single(conn: Connection) -> Self {
+            Self { conn: Rc::new(conn) }
+        }
+
+        /// Another handle to the connection. Cannot fail; the `Result` keeps
+        /// the signature identical to r2d2's so callers are written once.
+        pub fn get(&self) -> Result<SqliteConn, PoolError> {
+            Ok(SqliteConn(self.conn.clone()))
+        }
+    }
+
+    /// The error a `get()` would return if it could. It can't, so this has no
+    /// variants; it exists so `Error::SqlPoolError` has the same shape on both
+    /// targets.
+    #[derive(Debug, thiserror::Error)]
+    pub enum PoolError {}
+
+    #[derive(Debug)]
+    pub struct SqliteConn(Rc<Connection>);
+
+    impl Deref for SqliteConn {
+        type Target = Connection;
+        fn deref(&self) -> &Connection {
+            &self.0
+        }
+    }
+}
+
+pub use imp::*;