Update dev container & testing documentation.

.devcontainer/Dockerfile

@@ -1,28 +1,6 @@
-# See here for image contents: https://github.com/microsoft/vscode-dev-containers/tree/v0.234.0/containers/python-3/.devcontainer/base.Dockerfile
+FROM mcr.microsoft.com/devcontainers/rust
 
-# [Choice] Python version (use -bullseye variants on local arm64/Apple Silicon): 3, 3.10, 3.9, 3.8, 3.7, 3.6, 3-bullseye, 3.10-bullseye, 3.9-bullseye, 3.8-bullseye, 3.7-bullseye, 3.6-bullseye, 3-buster, 3.10-buster, 3.9-buster, 3.8-buster, 3.7-buster, 3.6-buster
-ARG VARIANT="3.10-bullseye"
-FROM mcr.microsoft.com/vscode/devcontainers/python:0-${VARIANT}
-
-# [Choice] Node.js version: none, lts/*, 16, 14, 12, 10
-ARG NODE_VERSION="none"
-RUN if [ "${NODE_VERSION}" != "none" ]; then su vscode -c "umask 0002 && . /usr/local/share/nvm/nvm.sh && nvm install ${NODE_VERSION} 2>&1"; fi
-
-# [Optional] If your pip requirements rarely change, uncomment this section to add them to the image.
-# COPY requirements.txt /tmp/pip-tmp/
-# RUN pip3 --disable-pip-version-check --no-cache-dir install -r /tmp/pip-tmp/requirements.txt \
-#    && rm -rf /tmp/pip-tmp
-
-# [Optional] Uncomment this section to install additional OS packages.
-# RUN apt-get update && export DEBIAN_FRONTEND=noninteractive \
-#     && apt-get -y install --no-install-recommends <your-package-list-here>
-
-# [Optional] Uncomment this line to install global node packages.
-# RUN su vscode -c "source /usr/local/share/nvm/nvm.sh && npm install -g <your-package-here>" 2>&1
-
-RUN cd /opt && curl -L https://github.com/WebAssembly/wasi-sdk/releases/download/wasi-sdk-22/wasi-sdk-22.0-linux.tar.gz \
-    | tar -xz
-ENV WASI_SDK_PATH=/opt/wasi-sdk-22.0
-
-RUN echo 'alias clang=/opt/wasi-sdk-22.0/bin/clang' >> /etc/bash.bashrc
-RUN echo 'alias clang++=/opt/wasi-sdk-22.0/bin/clang++' >> /etc/bash.bashrc
+COPY .devcontainer/setup.sh /tmp/setup.sh
+RUN chmod +x /tmp/setup.sh
+USER vscode
+RUN /tmp/setup.sh

.devcontainer/devcontainer.json

@@ -1,51 +1,11 @@
-// For format details, see https://aka.ms/devcontainer.json. For config options, see the README at:
-// https://github.com/microsoft/vscode-dev-containers/tree/v0.234.0/containers/python-3
+// For format details, see https://aka.ms/devcontainer.json.
 {
-	"name": "Dev",
-	"build": {
-		"dockerfile": "Dockerfile",
-		"context": "..",
-		"args": { 
-			// Update 'VARIANT' to pick a Python version: 3, 3.10, 3.9, 3.8, 3.7, 3.6
-			// Append -bullseye or -buster to pin to an OS version.
-			// Use -bullseye variants on local on arm64/Apple Silicon.
-			"VARIANT": "3.9",
-			// Options
-			"NODE_VERSION": "16"
-		}
-	},
-
-	// Set *default* container specific settings.json values on container create.
-	"settings": { 
-		"python.defaultInterpreterPath": "/usr/local/bin/python",
-		"python.linting.enabled": true,
-		"python.linting.pylintEnabled": true,
-		"python.formatting.autopep8Path": "/usr/local/py-utils/bin/autopep8",
-		"python.formatting.blackPath": "/usr/local/py-utils/bin/black",
-		"python.formatting.yapfPath": "/usr/local/py-utils/bin/yapf",
-		"python.linting.banditPath": "/usr/local/py-utils/bin/bandit",
-		"python.linting.flake8Path": "/usr/local/py-utils/bin/flake8",
-		"python.linting.mypyPath": "/usr/local/py-utils/bin/mypy",
-		"python.linting.pycodestylePath": "/usr/local/py-utils/bin/pycodestyle",
-		"python.linting.pydocstylePath": "/usr/local/py-utils/bin/pydocstyle",
-		"python.linting.pylintPath": "/usr/local/py-utils/bin/pylint"
-	},
-
-	// Add the IDs of extensions you want installed when the container is created.
-	"extensions": [
-		"ms-python.python",
-		"ms-python.vscode-pylance"
-	],
-
-	// Use 'forwardPorts' to make a list of ports inside the container available locally.
-	// "forwardPorts": [],
-
-	// Use 'postCreateCommand' to run commands after the container is created.
-	"postCreateCommand": "bash .devcontainer/finalize.sh",
-
-	// Comment out to connect as root instead. More info: https://aka.ms/vscode-remote/containers/non-root.
-	"remoteUser": "vscode",
-	"features": {
-		"rust": "latest"
-	}
+    "name": "Dev",
+    "build": {
+        "dockerfile": "Dockerfile",
+        "context": ".."
+    },
+
+    // Comment out to connect as root instead. More info: https://aka.ms/vscode-remote/containers/non-root.
+    "remoteUser": "vscode"
 }

.devcontainer/setup.sh

@@ -0,0 +1,29 @@
+#!/bin/sh
+set -e
+cd $HOME
+
+# Wasmtime: Used as default test runner.
+curl https://wasmtime.dev/install.sh -sSf | bash
+
+# Rust: Install additional targets not present in the docker base image.
+rustup target add wasm32-wasip2
+
+# C/C++
+WASI_SDK_PATH="$HOME/wasi-sdk-25.0"
+mkdir -p "$WASI_SDK_PATH"
+curl -L https://github.com/WebAssembly/wasi-sdk/releases/download/wasi-sdk-25/wasi-sdk-25.0-x86_64-linux.tar.gz | tar -xz -C "$WASI_SDK_PATH" --strip-components=1
+echo "export WASI_SDK_PATH=$WASI_SDK_PATH" >> ~/.bashrc
+echo "alias clang=$WASI_SDK_PATH/bin/clang" >> ~/.bashrc
+echo "alias clang++=$WASI_SDK_PATH/bin/clang++" >> ~/.bashrc
+
+# .NET
+DOTNET_PATH="$HOME/.dotnet"
+mkdir -p "$DOTNET_PATH"
+curl -sSL https://dot.net/v1/dotnet-install.sh -o $DOTNET_PATH/dotnet-install.sh
+chmod +x $DOTNET_PATH/dotnet-install.sh
+$DOTNET_PATH/dotnet-install.sh --channel 9.0 --install-dir $DOTNET_PATH
+echo "export PATH=$DOTNET_PATH:\$PATH" >> ~/.bashrc
+
+# Moonbit
+curl -fsSL https://cli.moonbitlang.com/install/unix.sh | bash
+echo 'export PATH="$HOME/.moon/bin:$PATH"' >> ~/.bashrc

tests/README.md

@@ -1,18 +1,27 @@
 # Testing wit-bindgen
 
-There are a few pre-requisites to testing the project. You only need the language compilers that you wish to run test against.
+## Setup
+### Dev container
+There are a few pre-requisites to testing the project. The easiest way to get
+started is by using the dev container part of this repository. That contains all
+the required toolchains in a single Docker container. 
+
+### Manual installation
+Alternatively, you can install the required tools by hand. You only need the
+language compilers that you wish to run test against.
 
 - WASI SDK
   - Download from wasi-sdk releases page. If you're using Windows, you need the one with mingw in its name.
-  - `curl -LO https://github.com/WebAssembly/wasi-sdk/releases/download/wasi-sdk-22/wasi-sdk-22.0-linux.tar.gz`
-  - Create an environment variable called `WASI_SDK_PATH`` giving the path where you extracted the WASI SDK download, i.e., the directory containing `bin`/`lib`/`share`` folders.
+  - `curl -LO https://github.com/WebAssembly/wasi-sdk/releases/download/wasi-sdk-25/wasi-sdk-25.0-x86_64-linux.tar.gz`
+  - Create an environment variable called `WASI_SDK_PATH` giving the path where you extracted the WASI SDK download, i.e., the directory containing `bin`/`lib`/`share` folders.
 - Compilers for the target language:
-  - Rust - wasi target: `rustup target add wasm32-wasip1`
-  - Java - TeaVM-WASI `ci/download-teamvm.sh`
-  - C - [Clang](https://clang.llvm.org/)
+  - Rust - wasi target: `rustup target add wasm32-wasip2`
+  - C - [Clang](https://clang.llvm.org/) (You can also use the one shipped with WASI SDK)
   - C# - [Dotnet 9](https://dotnet.microsoft.com/en-us/download/dotnet/9.0)
+  - [MoonBit](https://www.moonbitlang.com/download/)
 
-There are two suites of tests: [codegen](#testing-wit-bindgen---codegen) and [runtime](#testing-wit-bindgen---runtime).  To run all possible tests, across all supported languages, ensure the dependency above are installed then run:
+## Test structure
+There are two suites of tests: [codegen](#testing-wit-bindgen---codegen) and [runtime](#testing-wit-bindgen---runtime).  To run all possible tests, across all supported languages, ensure the dependencies above are installed then run:
 
 ```
 cargo test --workspace
@@ -55,11 +64,11 @@ Use `git submodule init` +  `git submodule update` before running the tests.
 
 The tests are generated by a macro `codegen_tests` in [crates/test-helpers](../crates/test-helpers/).
 
-You can run all `codegen` tests in rust with the following command:
+You can run the `codegen` tests for all languages with the following command:
 
 ```sh
 cargo run test \
-  --languages rust  \
+  --languages rust,c,cpp,csharp,moonbit \
   --artifacts target/artifacts \
   --rust-wit-bindgen-path ./crates/guest-rust \
   tests/codegen
@@ -77,7 +86,6 @@ wasm and executed on hosts. The code compiled-to-wasm can be one of:
 
 * `wasm.rs` - compiled with Rust to WebAssembly
 * `wasm.c` - compiled with Clang
-* `wasm.java` - compiled with TeaVM-WASI
 * `wasm.cs` - compiled with NativeAOT and Mono
 
 Existence of these files indicates that the language should be supported for the
@@ -90,6 +98,16 @@ Each of these hosts can also be omitted if the host doesn't implement the test
 or something like that. Otherwise for each host that exists when the host's
 crate generator crate is tested it will run all these tests.
 
+You can run the `runtime` tests for all languages with the following command:
+
+```sh
+cargo run test \
+  --languages rust,c,cpp,csharp,moonbit \
+  --artifacts target/artifacts \
+  --rust-wit-bindgen-path ./crates/guest-rust \
+  tests/runtime
+```
+
 ## Testing Layout
 
 If you're adding a test, all you should generally have to do is edit files in