Improved instrucitons on how to compile to wasm

lib/js-api/Cargo.toml

@@ -10,6 +10,9 @@ license = "MIT"
 readme = "README.md"
 edition = "2018"
 
+[lib]
+crate-type = ["cdylib", "rlib"]
+
 [dependencies]
 # executor = "0.8.0"
 wasm-bindgen = { version = "0.2.74" }
@@ -36,4 +39,3 @@ maintenance = { status = "actively-developed" }
 default = ["wat", "std"]
 std = []
 core = []
-

lib/js-api/README.md

@@ -42,6 +42,22 @@ Wasmer has the following configuration flags:
 * `wat` (enabled by default): It allows to read WebAssembly files in their text format.
   *This feature is normally used only in development environments*
 
+# Build
+
+You can use `wasm-pack` to build wasmer-js:
+
+```
+wasm-pack build --release
+```
+
+> The provided `wasmer_js.wasm` file should weight around 75kB when optmized via `wasm-opt` and stripped via `wasm-strip`, so it's relatively slim.
+
+# Test
+
+```
+wasm-pack test --node
+```
+
 ---
 
 Made with ❤️ by the Wasmer team, for the community