add unit tests

client/tests/scripts/fetch_multiple.js

@@ -0,0 +1,7 @@
+async function test() {
+  await libcurl.fetch("https://example.com/");
+  for (let i=0; i<20; i++) {
+    let r = await libcurl.fetch("https://example.com/");
+    assert(r.status === 200, "wrong status");  
+  }
+}

client/tests/scripts/fetch_once.js

@@ -0,0 +1,4 @@
+async function test() {
+  let r = await libcurl.fetch("https://example.com/");
+  assert(r.status === 200, "wrong status");
+}

client/tests/scripts/fetch_parallel.js

@@ -0,0 +1,8 @@
+async function test() {
+  await libcurl.fetch("https://www.example.com/");
+  let promises = [];
+  for (let i=0; i<10; i++) {
+      promises.push(libcurl.fetch("https://www.example.com/"))
+  }
+  await Promise.all(promises);
+}

client/tests/scripts/test_websocket.js

@@ -0,0 +1,24 @@
+function test() {
+  let message_len = 128*1024;
+
+  return new Promise((resolve, reject) => {
+    let ws = new libcurl.WebSocket("wss://echo.websocket.org");
+    ws.addEventListener("open", () => {
+      ws.send("hello".repeat(message_len));
+    });
+    
+    let messages = 0;
+    ws.addEventListener("message", (event) => {
+      messages += 1;
+      if (messages >= 2) {
+        if (event.data !== "hello".repeat(message_len)) reject("unexpected response");
+        if (messages >= 11) resolve();
+        ws.send("hello".repeat(message_len));
+      }
+    });
+
+    ws.addEventListener("error", () => {
+      reject("ws error occurred");
+    });
+  })
+}