From 5657303e97764cad59cdc7b641c942f4eba9eeba Mon Sep 17 00:00:00 2001
From: Hatter Jiang <jht5945@gmail.com>
Date: Sat, 30 May 2020 22:03:18 +0800
Subject: [PATCH] add test.ts

---
 deno_test_wasm/test.ts              | 30 +++++++++++++++++++++++++++++
 deno_test_wasm/test_wasm/build.sh   |  1 +
 deno_test_wasm/test_wasm/src/lib.rs |  1 +
 3 files changed, 32 insertions(+)
 create mode 100644 deno_test_wasm/test.ts
 create mode 100644 deno_test_wasm/test_wasm/build.sh

diff --git a/deno_test_wasm/test.ts b/deno_test_wasm/test.ts
new file mode 100644
index 0000000..542bdea
--- /dev/null
+++ b/deno_test_wasm/test.ts
@@ -0,0 +1,30 @@
+const wasmCode = await Deno.readFile("./test_wasm/target/wasm32-unknown-unknown/debug/test_wasm.wasm");
+const wasmModule = new WebAssembly.Module(wasmCode);
+const wasmInstance = new WebAssembly.Instance(wasmModule);
+
+const linearMemory = wasmInstance.exports.memory;
+
+function writeString() {
+    let s = "hello world !";
+    let encoded = new TextEncoder().encode(s);
+    let ptr = wasmInstance.exports.malloc(encoded.length);
+    const mem = new Uint8Array(linearMemory.buffer, ptr);
+    for (let i = 0; i < encoded.length; i++) {
+        mem[i] = encoded[i];
+    }
+    return ptr;
+}
+
+// from https://tilman.xyz/blog/2019/12/building-webassembly-for-deno/
+function readString(memory, ptr) {
+    const mem = new Uint8Array(memory.buffer, ptr);
+    let length;
+    for (length = 0; mem[length] !== 0; length ++);
+    return new TextDecoder("utf-8").decode(new Uint8Array(mem.buffer, ptr, length));
+}
+
+let ptr = writeString();
+console.log("DECODED:\n" + readString(linearMemory, ptr) + " @" + ptr);
+
+let ptr2 = wasmInstance.exports.to_uppercase(ptr);
+console.log("DECODED:\n" + readString(linearMemory, ptr2) + " @" + ptr2);
diff --git a/deno_test_wasm/test_wasm/build.sh b/deno_test_wasm/test_wasm/build.sh
new file mode 100644
index 0000000..b878198
--- /dev/null
+++ b/deno_test_wasm/test_wasm/build.sh
@@ -0,0 +1 @@
+cargo build --target wasm32-unknown-unknown
diff --git a/deno_test_wasm/test_wasm/src/lib.rs b/deno_test_wasm/test_wasm/src/lib.rs
index 74ef50e..4532acb 100644
--- a/deno_test_wasm/test_wasm/src/lib.rs
+++ b/deno_test_wasm/test_wasm/src/lib.rs
@@ -7,6 +7,7 @@ pub extern "C" fn malloc(len: usize) -> *mut c_char {
     s.into_raw()
 }
 
+#[no_mangle]
 pub extern "C" fn to_uppercase(ptr: *mut c_char) -> *mut c_char {
     let s = unsafe { CString::from_raw(ptr) };
     let s2 = CString::new(s.to_string_lossy().to_uppercase()).unwrap();