From 8891fb79305675d89745cb5d04f38bbc72401d2e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Philip=20Dub=C3=A9?= <philip@peerdb.io>
Date: Tue, 24 Sep 2024 13:31:57 +0000
Subject: [PATCH] Server side parameters via with_param

Fixes #142
---
 src/lib.rs        | 13 ++++++++++++-
 src/query.rs      | 12 +++++++++++-
 tests/it/query.rs | 25 +++++++++++++++++++++++++
 3 files changed, 48 insertions(+), 2 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index 6df4a50..8d5c16f 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -5,7 +5,8 @@
 #[macro_use]
 extern crate static_assertions;
 
-use self::{error::Result, http_client::HttpClient};
+use self::{error::Result, http_client::HttpClient, sql::Bind};
+use ::serde::Serialize;
 use std::{collections::HashMap, fmt::Display, sync::Arc};
 
 pub use self::{compression::Compression, row::Row};
@@ -160,6 +161,16 @@ impl Client {
         self
     }
 
+    pub fn with_param(
+        self,
+        name: impl Into<String>,
+        value: impl Bind + Serialize,
+    ) -> Result<Self, String> {
+        let mut param = String::from("param_");
+        Bind::write(&value, &mut param)?;
+        Ok(self.with_option(name, param))
+    }
+
     /// Used to specify a header that will be passed to all queries.
     ///
     /// # Example
diff --git a/src/query.rs b/src/query.rs
index 926fdb5..b9f998f 100644
--- a/src/query.rs
+++ b/src/query.rs
@@ -1,5 +1,5 @@
 use hyper::{header::CONTENT_LENGTH, Method, Request};
-use serde::Deserialize;
+use serde::{Deserialize, Serialize};
 use std::fmt::Display;
 use url::Url;
 
@@ -195,6 +195,16 @@ impl Query {
         self.client.add_option(name, value);
         self
     }
+
+    pub fn with_param(
+        self,
+        name: impl Into<String>,
+        value: impl Bind + Serialize,
+    ) -> Result<Self, String> {
+        let mut param = String::from("param_");
+        Bind::write(&value, &mut param)?;
+        Ok(self.with_option(name, param))
+    }
 }
 
 /// A cursor that emits rows.
diff --git a/tests/it/query.rs b/tests/it/query.rs
index 80e0158..b747495 100644
--- a/tests/it/query.rs
+++ b/tests/it/query.rs
@@ -85,6 +85,31 @@ async fn fetch_one_and_optional() {
     assert_eq!(got_string, "bar");
 }
 
+#[tokio::test]
+async fn server_side_param() {
+    let client = prepare_database!()
+        .with_param("val1", 42)
+        .expect("failed to bind 42");
+
+    let result = client
+        .query("SELECT plus({val1: Int32}, {val2: String}) AS result")
+        .with_param("val2", 144)
+        .expect("failed to bind 144")
+        .fetch_one::<u64>()
+        .await
+        .expect("failed to fetch u64");
+    assert_eq!(result, 186);
+
+    let result = client
+        .query("SELECT {val1: String} AS result")
+        .with_param("param_val1", "string")
+        .expect("failed to bind \"string\"")
+        .fetch_one::<String>()
+        .await
+        .expect("failed to fetch string");
+    assert_eq!(result, "string");
+}
+
 // See #19.
 #[tokio::test]
 async fn long_query() {