feat(api) Merge js-api into api.

This patch takes the entire `wasmer-js` crate and merges it into the
`wasmer` crate.

Inside the `lib/api/src/` directory, there are 2 new directories:

1. a new `sys` directory, which contains the usual `wasmer` crate
   implementation,
2. a new directory `js`, which contains the implementation of
   `wasmer-js`.

The `Cargo.toml` file is still compatible. The `default` feature
fallbacks to `sys-default`, which enables the `sys` feature. All
features related to compilers or engines or anything else prior this
patch, activates the `sys` feature.

Parallel to that, there is a `js-default` and `js` features.

The `Cargo.toml` file is extensively documented to explain what are
dependencies, dev-dependencies, features and other sections related to
`sys` or to `js`.

There is a bug with `wasm_bindgen_test` where it doesn't compile or
look for tests in `tests/*/<test>.rs`. The hack is to name files
`tests/js_<test>.rs`. Ugly, but it works.

Cargo.toml

@@ -43,7 +43,6 @@ members = [
     "lib/engine-universal",
     "lib/engine-dylib",
     "lib/engine-staticlib",
-    "lib/js-api",
     "lib/object",
     "lib/vm",
     "lib/wasi",

lib/api/Cargo.toml

@@ -10,96 +10,209 @@ license = "MIT"
 readme = "README.md"
 edition = "2018"
 
+[lib]
+crate-type = ["cdylib", "rlib"]
+
+#####
+#
+# This crate comes in 2 major flavors:
+#
+# * `sys`, where `wasmer` will be compiled to a native executable
+#    which provides compilers, engines, a full VM etc.
+# * `js`, where `wasmer` will be compiled to WebAssembly to run in a
+#   JavaScript host.
+#
+#####
+
+#####
+#
+# Shared dependencies.
 [dependencies]
+#
+# ## Mandatory shared dependencies.
+#
+indexmap = { version = "1.6", features = ["serde-1"] }
+cfg-if = "1.0"
+thiserror = "1.0"
+more-asserts = "0.2"
+#
+# ## Optional shared dependencies.
+#
+wat = { version = "1.0", optional = true }
+#
+#####
+
+#####
+#
+# # Dependencies and Development Dependencies for `sys`.
+#
+[target.'cfg(not(target_arch = "wasm32"))'.dependencies]
+#
+# ## Mandatory dependencies for `sys`.
+#
 wasmer-vm = { path = "../vm", version = "2.0.0" }
-wasmer-compiler-singlepass = { path = "../compiler-singlepass", version = "2.0.0", optional = true }
-wasmer-compiler-cranelift = { path = "../compiler-cranelift", version = "2.0.0", optional = true }
-wasmer-compiler-llvm = { path = "../compiler-llvm", version = "2.0.0", optional = true }
 wasmer-compiler = { path = "../compiler", version = "2.0.0" }
 wasmer-derive = { path = "../derive", version = "2.0.0" }
 wasmer-engine = { path = "../engine", version = "2.0.0" }
-wasmer-engine-universal = { path = "../engine-universal", version = "2.0.0", optional = true }
-wasmer-engine-dylib = { path = "../engine-dylib", version = "2.0.0", optional = true }
 wasmer-types = { path = "../types", version = "2.0.0" }
-indexmap = { version = "1.6", features = ["serde-1"] }
-cfg-if = "1.0"
-wat = { version = "1.0", optional = true }
-thiserror = "1.0"
-more-asserts = "0.2"
 target-lexicon = { version = "0.12", default-features = false }
 loupe = "0.1"
-
-[target.'cfg(target_os = "windows")'.dependencies]
+#
+# ## Optional dependencies for `sys`.
+#
+wasmer-compiler-singlepass = { path = "../compiler-singlepass", version = "2.0.0", optional = true }
+wasmer-compiler-cranelift = { path = "../compiler-cranelift", version = "2.0.0", optional = true }
+wasmer-compiler-llvm = { path = "../compiler-llvm", version = "2.0.0", optional = true }
+wasmer-engine-universal = { path = "../engine-universal", version = "2.0.0", optional = true }
+wasmer-engine-dylib = { path = "../engine-dylib", version = "2.0.0", optional = true }
+#
+# ## Mandatory dependencies for `sys` on Windows.
+#
+[target.'cfg(all(not(target_arch = "wasm32"), target_os = "windows"))'.dependencies]
+#
 winapi = "0.3"
-
-[dev-dependencies]
-# for the binary wasmer.rs
-libc = { version = "^0.2", default-features = false }
+#
+# ## Development Dependencies for `sys`.
+#
+[target.'cfg(not(target_arch = "wasm32"))'.dev-dependencies]
+#
+libc = { version = "^0.2", default-features = false } # for the binary wasmer.rs
 wat = "1.0"
 tempfile = "3.1"
 anyhow = "1.0"
+#
+#####
+
+#####
+#
+# # Dependencies and Develoment Dependencies for `js`.
+#
+[target.'cfg(target_arch = "wasm32")'.dependencies]
+#
+# ## Mandatory dependencies for `js`.
+#
+wasmer-types = { path = "../types", version = "2.0.0", default-features = false, features = ["std"] }
+wasm-bindgen = "0.2.74"
+js-sys = "0.3.51"
+wasmer-derive = { path = "../derive", version = "2.0.0" }
+#
+# ## Optional dependencies for `js`.
+#
+wasmparser = { version = "0.78", default-features = false, optional = true }
+hashbrown = { version = "0.11", optional = true }
+#
+# ## Development Dependencies for `js`.
+#
+[target.'cfg(target_arch = "wasm32")'.dev-dependencies]
+#
+wat = "1.0"
+anyhow = "1.0"
+wasm-bindgen-test = "0.3.0"
+#
+#####
+
+#####
+#
+# # Specific to `js`.
+#
+# `wasm-opt` is on by default in for the release profile, but it can be
+# disabled by setting it to `false`
+[package.metadata.wasm-pack.profile.release]
+wasm-opt = false
+#
+####
 
 [badges]
 maintenance = { status = "actively-developed" }
 
 [features]
-default = ["wat", "default-cranelift", "default-universal"]
+default = ["sys-default"]
+
+#####
+#
+# # Features for `sys`.
+#
+sys = []
+sys-default = ["sys", "wat", "default-cranelift", "default-universal"]
+#
+# ## Compilers.
+#
 compiler = [
+    "sys",
     "wasmer-compiler/translator",
     "wasmer-engine-universal/compiler",
     "wasmer-engine-dylib/compiler",
 ]
-engine = []
-universal = [
-    "wasmer-engine-universal",
-    "engine"
-]
-dylib = [
-    "wasmer-engine-dylib",
-    "engine"
-]
-singlepass = [
-    "wasmer-compiler-singlepass",
-    "compiler",
-]
-cranelift = [
-    "wasmer-compiler-cranelift",
-    "compiler",
-]
-llvm = [
-    "wasmer-compiler-llvm",
-    "compiler",
-]
-
-default-singlepass = [
-    "singlepass",
-    "default-compiler"
-]
-default-cranelift = [
-    "cranelift",
-    "default-compiler"
-]
-default-llvm = [
-    "llvm",
-    "default-compiler"
-]
-default-universal = [
-    "universal",
-    "default-engine"
-]
-default-dylib = [
-    "dylib",
-    "default-engine"
-]
-
+    singlepass = [
+        "compiler",
+        "wasmer-compiler-singlepass",
+    ]
+    cranelift = [
+        "compiler",
+        "wasmer-compiler-cranelift",
+    ]
+    llvm = [
+        "compiler",
+        "wasmer-compiler-llvm",
+    ]
 default-compiler = []
+    default-singlepass = [
+        "default-compiler",
+        "singlepass",
+    ]
+    default-cranelift = [
+        "default-compiler",
+        "cranelift",
+    ]
+    default-llvm = [
+        "default-compiler",
+        "llvm",
+    ]
+#
+# ## Engines.
+#
+engine = ["sys"]
+    universal = [
+        "engine",
+        "wasmer-engine-universal",
+    ]
+    dylib = [
+        "engine",
+        "wasmer-engine-dylib",
+    ]
 default-engine = []
-
-# experimental / in-development features
+    default-universal = [
+        "default-engine",
+        "universal",
+    ]
+    default-dylib = [
+        "default-engine",
+        "dylib",
+    ]
+#
+# ## Experimental / in-development features
+#
 experimental-reference-types-extern-ref = [
+    "sys",
     "wasmer-types/experimental-reference-types-extern-ref",
 ]
-
-# Deprecated features.
+#
+# ## Deprecated features.
+#
 jit = ["universal"]
 native = ["dylib"]
+#
+#####
+
+#####
+#
+# # Features for `js`.
+#
+js = []
+js-default = ["js", "std", "wasm-types-polyfill", "wat"]
+#
+wasm-types-polyfill = ["js", "wasmparser"]
+std = ["js"]
+core = ["js", "hashbrown"]
+#
+#####

lib/js-api/src/env.rs → lib/api/src/js/env.rs

@@ -1,4 +1,4 @@
-use crate::{ExportError, Instance};
+use crate::js::{ExportError, Instance};
 use thiserror::Error;
 
 /// An error while initializing the user supplied host env with the `WasmerEnv` trait.

lib/js-api/src/error.rs → lib/api/src/js/error.rs

@@ -1,4 +1,4 @@
-use crate::lib::std::string::String;
+use crate::js::lib::std::string::String;
 #[cfg(feature = "std")]
 use thiserror::Error;
 

lib/js-api/src/export.rs → lib/api/src/js/export.rs

@@ -1,7 +1,7 @@
-use crate::instance::Instance;
-use crate::wasm_bindgen_polyfill::Global;
-use crate::HostEnvInitError;
-use crate::WasmerEnv;
+use crate::js::instance::Instance;
+use crate::js::wasm_bindgen_polyfill::Global;
+use crate::js::HostEnvInitError;
+use crate::js::WasmerEnv;
 use js_sys::Function;
 use js_sys::WebAssembly::{Memory, Table};
 use std::cell::RefCell;