Prototype server plugins, add example MoonScript plugin

Cargo.lock

@@ -94,6 +94,15 @@ dependencies = [
  "byteorder 1.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "bincode"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "byteorder 1.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde 1.0.84 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "bitflags"
 version = "0.7.0"
@@ -1224,6 +1233,7 @@ dependencies = [
 name = "rojo"
 version = "0.5.0-alpha.0"
 dependencies = [
+ "bincode 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "clap 2.32.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "csv 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "env_logger 0.5.13 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1251,6 +1261,16 @@ dependencies = [
 name = "rojo-e2e"
 version = "0.1.0"
 
+[[package]]
+name = "rojo-plugin-moonscript"
+version = "0.1.0"
+dependencies = [
+ "bincode 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde 1.0.84 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde_derive 1.0.84 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde_json 1.0.34 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "rouille"
 version = "2.2.0"
@@ -1868,6 +1888,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum backtrace-sys 0.1.28 (registry+https://github.com/rust-lang/crates.io-index)" = "797c830ac25ccc92a7f8a7b9862bde440715531514594a6154e3d4a54dd769b6"
 "checksum base64 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)" = "621fc7ecb8008f86d7fb9b95356cd692ce9514b80a86d85b397f32a22da7b9e2"
 "checksum base64 0.9.3 (registry+https://github.com/rust-lang/crates.io-index)" = "489d6c0ed21b11d038c31b6ceccca973e65d73ba3bd8ecb9a2babf5546164643"
+"checksum bincode 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "9f2fb9e29e72fd6bc12071533d5dc7664cb01480c59406f656d7ac25c7bd8ff7"
 "checksum bitflags 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "aad18937a628ec6abcd26d1489012cc0e18c21798210f491af69ded9b881106d"
 "checksum bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "228047a76f468627ca71776ecdebd732a3423081fcf5125585bcd7c49886ce12"
 "checksum brotli-sys 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)" = "4445dea95f4c2b41cde57cc9fee236ae4dbae88d8fcbdb4750fc1bb5d86aaecd"

Cargo.toml

@@ -2,4 +2,5 @@
 members = [
 	"server",
 	"rojo-e2e",
+	"rojo-plugin-moonscript",
 ]

rojo-plugin-moonscript/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "rojo-plugin-moonscript"
+version = "0.1.0"
+authors = ["Lucien Greathouse <me@lpghatguy.com>"]
+edition = "2018"
+
+[dependencies]
+serde = "1.0"
+serde_derive = "1.0"
+serde_json = "1.0"
+bincode = "1.0"

rojo-plugin-moonscript/src/main.rs

@@ -0,0 +1,80 @@
+use std::{
+    collections::HashMap,
+    io::{self, Write},
+    path::PathBuf,
+    process::{Command, Stdio},
+};
+
+use serde_derive::{Serialize, Deserialize};
+
+#[derive(Debug, Deserialize)]
+struct InputFile {
+    path: PathBuf,
+    contents: Vec<u8>,
+}
+
+#[derive(Debug, Serialize)]
+struct Metadata {
+    ignore_unknown_instances: bool,
+}
+
+#[derive(Debug, Serialize)]
+#[serde(tag = "Type")]
+enum Property {
+    #[serde(rename_all = "PascalCase")]
+    String {
+        value: String,
+    },
+}
+
+#[derive(Debug, Serialize)]
+struct Instance {
+    name: String,
+    class_name: String,
+    properties: HashMap<String, Property>,
+    children: Vec<()>,
+    metadata: Metadata,
+}
+
+fn main() -> io::Result<()> {
+    let file: InputFile = bincode::deserialize_from(io::stdin())
+        .expect("Invalid input");
+
+    let mut child = Command::new("moonc")
+        .arg("--")
+        .stdin(Stdio::piped())
+        .stdout(Stdio::piped())
+        .spawn()?;
+
+    {
+        let stdin = child.stdin.as_mut().unwrap();
+        stdin.write_all(&file.contents)?;
+    }
+
+    let result = child.wait_with_output()?;
+
+    let script_name = file.path.file_stem().unwrap().to_string_lossy().into_owned();
+    let compiled = String::from_utf8_lossy(&result.stdout).into_owned();
+
+    let mut properties = HashMap::new();
+    properties.insert("Source".to_owned(), Property::String {
+        value: compiled,
+    });
+
+    let output = Instance {
+        name: script_name,
+        class_name: "ModuleScript".to_owned(),
+        properties,
+        children: Vec::new(),
+        metadata: Metadata {
+            ignore_unknown_instances: false,
+        },
+    };
+
+    let response = serde_json::to_string(&output)
+        .expect("Couldn't serialize to JSON");
+
+    print!("{}", response);
+
+    Ok(())
+}

server/Cargo.toml

@@ -20,6 +20,7 @@ default = []
 bundle-plugin = []
 
 [dependencies]
+bincode = "1.0"
 clap = "2.27"
 csv = "1.0"
 env_logger = "0.5"

server/src/rbx_snapshot.rs

@@ -3,6 +3,7 @@ use std::{
     collections::HashMap,
     fmt,
     path::{Path, PathBuf},
+    process::{Command, Stdio},
     str,
 };
 
@@ -33,6 +34,13 @@ use crate::{
     rbx_session::{MetadataPerPath, MetadataPerInstance},
 };
 
+// In a real plugin implementation, this would be part of the project file.
+// Should the executable name be limited to try to prevent malicious projects
+// from executing arbitrary code?
+static PLUGINS: [(&str, &str); 1] = [
+    ("moon", "target/debug/rojo-plugin-moonscript"),
+];
+
 const INIT_MODULE_NAME: &str = "init.lua";
 const INIT_SERVER_NAME: &str = "init.server.lua";
 const INIT_CLIENT_NAME: &str = "init.client.lua";
@@ -246,7 +254,65 @@ fn snapshot_imfs_file<'source>(
         Some("txt") => snapshot_txt_file(file)?,
         Some("rbxmx") => snapshot_xml_model_file(file)?,
         Some("rbxm") => snapshot_binary_model_file(file)?,
-        Some(_) | None => return Ok(None),
+        // In a real plugin implementation, plugins would probably want to
+        // execute before any of the builtin instance routines.
+        //
+        // Alternatively, maybe we want to run the builtin routines and send the
+        // snapshot generated by that routine as well as the original file? That
+        // would open the door to make plugins that transform instances to do
+        // things like add source headers or optimize code without having to
+        // create another kind of plugin.
+        Some(unknown_ext) => {
+            let mut result = None;
+
+            for (plugin_ext, plugin_path) in &PLUGINS {
+                if plugin_ext == &unknown_ext {
+                    let mut child = Command::new(plugin_path)
+                        // This argument is standard for telling processes to
+                        // read from stdin, we can pass it as a courtesy even
+                        // though I bet all plugin processes will be
+                        // purpose-built to correctly deal with structured input
+                        // from Rojo
+                        .arg("--")
+                        .stdin(Stdio::piped())
+                        .stdout(Stdio::piped())
+                        .spawn()
+                        .expect("Could not spawn plugin process");
+
+                    {
+                        let stdin = child.stdin.as_mut().unwrap();
+                        // We're using bincode here since it makes Vec<u8>
+                        // serialize more cleanly than JSON, but we could use
+                        // whatever.
+                        bincode::serialize_into(stdin, file)
+                            .expect("Could not serialize file into plugin stdin");
+                    }
+
+                    let output = child.wait_with_output()
+                        .expect("Could not wait for plugin process output");
+
+                    assert!(output.status.success());
+
+                    // I'm accepting JSON for the output because bincode doesn't
+                    // implement all of the features needed to actually
+                    // deserialize a RbxSnapshotInstance I guess.
+                    //
+                    // Whatever format is used for plugins, it should probably
+                    // be consistent between input/output.
+                    //
+                    // This also doesn't account for representing failure or a
+                    // plugin returning no instance at all.
+                    let snapshot: RbxSnapshotInstance<'static> = serde_json::from_slice(&output.stdout)
+                        .expect("Could not deserialize plugin output");
+
+                    result = Some(snapshot);
+                    break;
+                }
+            }
+
+            result
+        },
+        None => return Ok(None),
     };
 
     if let Some(snapshot) = maybe_snapshot.as_mut() {

server/src/snapshot_reconciler.rs

@@ -55,7 +55,7 @@ impl InstanceChanges {
     }
 }
 
-#[derive(Debug)]
+#[derive(Debug, Deserialize)]
 pub struct RbxSnapshotInstance<'a> {
     pub name: Cow<'a, str>,
     pub class_name: Cow<'a, str>,

test-projects/moonscript/roblox-project.json

@@ -0,0 +1,6 @@
+{
+  "name": "moonscript",
+  "tree": {
+    "$path": "src"
+  }
+}

test-projects/moonscript/src/hello.moon

@@ -0,0 +1 @@
+func_a = -> print "Hello, world!"