Allow for custom HTTPHrnResolvers

This allows for giving a custom reqwest client when creating a
HTTPHrnResolver. This is useful for adding custom headers, proxying
connections, etc. This also has the added benefit of using the same
reqwest client across every call so it'll be better and reusing
tls connections.

Author: benthecarman

src/http_resolver.rs

@@ -29,7 +29,28 @@ const DOH_ENDPOINT: &'static str = "https://dns.google/dns-query?dns=";
 ///
 /// Note that using this may reveal our IP address to the recipient and information about who we're
 /// paying to Google (via `dns.google`).
-pub struct HTTPHrnResolver;
+#[derive(Debug, Clone)]
+pub struct HTTPHrnResolver {
+	client: reqwest::Client,
+}
+
+impl HTTPHrnResolver {
+	/// Create a new `HTTPHrnResolver` with a default `reqwest::Client`.
+	pub fn new() -> Self {
+		HTTPHrnResolver::default()
+	}
+
+	/// Create a new `HTTPHrnResolver` with a custom `reqwest::Client`.
+	pub fn with_client(client: reqwest::Client) -> Self {
+		HTTPHrnResolver { client }
+	}
+}
+
+impl Default for HTTPHrnResolver {
+	fn default() -> Self {
+		HTTPHrnResolver { client: reqwest::Client::new() }
+	}
+}
 
 const B64_CHAR: [u8; 64] = [
 	b'A', b'B', b'C', b'D', b'E', b'F', b'G', b'H', b'I', b'J', b'K', b'L', b'M', b'N', b'O', b'P',
@@ -107,11 +128,10 @@ impl HTTPHrnResolver {
 		let mut pending_queries = vec![initial_query];
 
 		while let Some(query) = pending_queries.pop() {
-			let client = reqwest::Client::new();
-
 			let request_url = query_to_url(query);
-			let req = client.get(request_url).header("accept", "application/dns-message").build();
-			let resp = client.execute(req.map_err(|_| DNS_ERR)?).await.map_err(|_| DNS_ERR)?;
+			let req =
+				self.client.get(request_url).header("accept", "application/dns-message").build();
+			let resp = self.client.execute(req.map_err(|_| DNS_ERR)?).await.map_err(|_| DNS_ERR)?;
 			let body = resp.bytes().await.map_err(|_| DNS_ERR)?;
 
 			let mut answer = QueryBuf::new_zeroed(0);
@@ -136,8 +156,15 @@ impl HTTPHrnResolver {
 
 	async fn resolve_lnurl_impl(&self, lnurl_url: &str) -> Result<HrnResolution, &'static str> {
 		let err = "Failed to fetch LN-Address initial well-known endpoint";
-		let init: LNURLInitResponse =
-			reqwest::get(lnurl_url).await.map_err(|_| err)?.json().await.map_err(|_| err)?;
+		let init: LNURLInitResponse = self
+			.client
+			.get(lnurl_url)
+			.send()
+			.await
+			.map_err(|_| err)?
+			.json()
+			.await
+			.map_err(|_| err)?;
 
 		if init.tag != "payRequest" {
 			return Err("LNURL initial init_response had an incorrect tag value");
@@ -198,8 +225,15 @@ impl HrnResolver for HTTPHrnResolver {
 			} else {
 				write!(&mut callback, "?amount={}", amt.milli_sats()).expect("Write to String");
 			}
-			let callback_response: LNURLCallbackResponse =
-				reqwest::get(callback).await.map_err(|_| err)?.json().await.map_err(|_| err)?;
+			let callback_response: LNURLCallbackResponse = self
+				.client
+				.get(callback)
+				.send()
+				.await
+				.map_err(|_| err)?
+				.json()
+				.await
+				.map_err(|_| err)?;
 
 			if !callback_response.routes.is_empty() {
 				return Err("LNURL callback response contained a non-empty routes array");
@@ -257,7 +291,7 @@ mod tests {
 
 	#[tokio::test]
 	async fn test_dns_via_http_hrn_resolver() {
-		let resolver = HTTPHrnResolver;
+		let resolver = HTTPHrnResolver::default();
 		let instructions = PaymentInstructions::parse(
 			"[email protected]",
 			bitcoin::Network::Bitcoin,
@@ -303,10 +337,11 @@ mod tests {
 
 	#[tokio::test]
 	async fn test_http_hrn_resolver() {
+		let resolver = HTTPHrnResolver::default();
 		let instructions = PaymentInstructions::parse(
 			"[email protected]",
 			bitcoin::Network::Bitcoin,
-			&HTTPHrnResolver,
+			&resolver,
 			true,
 		)
 		.await
@@ -323,7 +358,7 @@ mod tests {
 			assert_eq!(hrn.user(), "lnurltest");
 			assert_eq!(hrn.domain(), "bitcoin.ninja");
 
-			instr.set_amount(Amount::from_sats(100_000).unwrap(), &HTTPHrnResolver).await.unwrap()
+			instr.set_amount(Amount::from_sats(100_000).unwrap(), &resolver).await.unwrap()
 		} else {
 			panic!();
 		};
@@ -348,11 +383,12 @@ mod tests {
 
 	#[tokio::test]
 	async fn test_http_lnurl_resolver() {
+		let resolver = HTTPHrnResolver::default();
 		let instructions = PaymentInstructions::parse(
 			// lnurl encoding for [email protected]
 			"lnurl1dp68gurn8ghj7cnfw33k76tw9ehxjmn2vyhjuam9d3kz66mwdamkutmvde6hymrs9akxuatjd36x2um5ahcq39",
 			Network::Bitcoin,
-			&HTTPHrnResolver,
+			&resolver,
 			true,
 		)
 		.await
@@ -365,7 +401,7 @@ mod tests {
 			assert_eq!(instr.pop_callback(), None);
 			assert!(instr.bip_353_dnssec_proof().is_none());
 
-			instr.set_amount(Amount::from_sats(100_000).unwrap(), &HTTPHrnResolver).await.unwrap()
+			instr.set_amount(Amount::from_sats(100_000).unwrap(), &resolver).await.unwrap()
 		} else {
 			panic!();
 		};