Add YAML middleware

Cargo.toml

@@ -57,6 +57,11 @@ rbx_reflection = "4.5.0"
 rbx_reflection_database = "0.2.10"
 rbx_xml = "0.13.3"
 
+serde = { version = "1.0.197", features = ["derive", "rc"] }
+serde_json = "1.0.114"
+serde_yaml = "0.8.26"
+toml = "0.5.11"
+
 anyhow = "1.0.80"
 backtrace = "0.3.69"
 bincode = "1.3.3"
@@ -81,9 +86,6 @@ reqwest = { version = "0.11.24", default-features = false, features = [
 ] }
 ritz = "0.1.0"
 roblox_install = "1.0.0"
-serde = { version = "1.0.197", features = ["derive", "rc"] }
-serde_json = "1.0.114"
-toml = "0.5.11"
 termcolor = "1.4.1"
 thiserror = "1.0.57"
 tokio = { version = "1.36.0", features = ["rt", "rt-multi-thread"] }
@@ -111,6 +113,5 @@ criterion = "0.3.6"
 insta = { version = "1.36.1", features = ["redactions", "yaml"] }
 paste = "1.0.14"
 pretty_assertions = "1.4.0"
-serde_yaml = "0.8.26"
 tempfile = "3.10.1"
 walkdir = "2.5.0"

src/snapshot_middleware/mod.rs

@@ -17,6 +17,7 @@ mod rbxmx;
 mod toml;
 mod txt;
 mod util;
+mod yaml;
 
 use std::{
     path::{Path, PathBuf},
@@ -41,6 +42,7 @@ use self::{
     rbxmx::snapshot_rbxmx,
     toml::snapshot_toml,
     txt::snapshot_txt,
+    yaml::snapshot_yaml,
 };
 
 pub use self::{project::snapshot_project_node, util::emit_legacy_scripts_default};
@@ -204,6 +206,7 @@ pub enum Middleware {
     Rbxmx,
     Toml,
     Text,
+    Yaml,
     Ignore,
 }
 
@@ -229,6 +232,7 @@ impl Middleware {
             Self::Rbxmx => snapshot_rbxmx(context, vfs, path, name),
             Self::Toml => snapshot_toml(context, vfs, path, name),
             Self::Text => snapshot_txt(context, vfs, path, name),
+            Self::Yaml => snapshot_yaml(context, vfs, path, name),
             Self::Ignore => Ok(None),
         }
     }

src/snapshot_middleware/snapshots/librojo__snapshot_middleware__yaml__test__instance_from_vfs.snap

@@ -0,0 +1,20 @@
+---
+source: src/snapshot_middleware/yaml.rs
+expression: instance_snapshot
+---
+snapshot_id: "00000000000000000000000000000000"
+metadata:
+  ignore_unknown_instances: false
+  instigating_source:
+    Path: /foo.yml
+  relevant_paths:
+    - /foo.yml
+    - /foo.meta.json
+  context:
+    emit_legacy_scripts: true
+name: foo
+class_name: ModuleScript
+properties:
+  Source:
+    String: "return {\n\tstring = \"this is a string\",\n\tboolean = true,\n\tnumber = 1337,\n\t[\"value-with-hypen\"] = \"it sure is\",\n\tsequence = {\"wow\", 8675309},\n\tmap = {{\n\t\tkey = \"value\",\n\t}, {\n\t\tkey2 = \"value 2\",\n\t}, {\n\t\tkey3 = \"value 3\",\n\t}},\n\twhatever_this_is = {\"i imagine\", \"it's\", \"a\", \"sequence?\"},\n}"
+children: []

src/snapshot_middleware/yaml.rs

@@ -0,0 +1,116 @@
+use std::path::Path;
+
+use anyhow::Context;
+use maplit::hashmap;
+use memofs::{IoResultExt, Vfs};
+
+use crate::{
+    lua_ast::{Expression, Statement},
+    snapshot::{InstanceContext, InstanceMetadata, InstanceSnapshot},
+};
+
+use super::meta_file::AdjacentMetadata;
+
+pub fn snapshot_yaml(
+    context: &InstanceContext,
+    vfs: &Vfs,
+    path: &Path,
+    name: &str,
+) -> anyhow::Result<Option<InstanceSnapshot>> {
+    let contents = vfs.read(path)?;
+
+    let value: serde_yaml::Value = serde_yaml::from_slice(&contents)
+        .with_context(|| format!("File contains malformed YAML: {}", path.display()))?;
+
+    let as_lua = yaml_to_lua(value).to_string();
+
+    let properties = hashmap! {
+        "Source".to_owned() => as_lua.into(),
+    };
+
+    let meta_path = path.with_file_name(format!("{}.meta.json", name));
+
+    let mut snapshot = InstanceSnapshot::new()
+        .name(name)
+        .class_name("ModuleScript")
+        .properties(properties)
+        .metadata(
+            InstanceMetadata::new()
+                .instigating_source(path)
+                .relevant_paths(vec![path.to_path_buf(), meta_path.clone()])
+                .context(context),
+        );
+
+    if let Some(meta_contents) = vfs.read(&meta_path).with_not_found()? {
+        let mut metadata = AdjacentMetadata::from_slice(&meta_contents, meta_path)?;
+        metadata.apply_all(&mut snapshot)?;
+    }
+
+    Ok(Some(snapshot))
+}
+
+fn yaml_to_lua(value: serde_yaml::Value) -> Statement {
+    Statement::Return(yaml_to_lua_value(value))
+}
+
+fn yaml_to_lua_value(value: serde_yaml::Value) -> Expression {
+    use serde_yaml::Value;
+
+    match value {
+        Value::Bool(value) => Expression::Bool(value),
+        Value::Null => Expression::Nil,
+        Value::Number(value) => Expression::Number(value.as_f64().unwrap()),
+        Value::String(value) => Expression::String(value),
+        Value::Mapping(map) => Expression::table(
+            map.into_iter()
+                .map(|(key, value)| (yaml_to_lua_value(key), yaml_to_lua_value(value)))
+                .collect(),
+        ),
+        Value::Sequence(seq) => Expression::Array(seq.into_iter().map(yaml_to_lua_value).collect()),
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    use memofs::{InMemoryFs, VfsSnapshot};
+
+    #[test]
+    fn instance_from_vfs() {
+        let mut imfs = InMemoryFs::new();
+        imfs.load_snapshot(
+            "/foo.yml",
+            VfsSnapshot::file(
+                r#"
+---
+string: this is a string
+boolean: true
+number: 1337
+value-with-hypen: it sure is
+sequence:
+  - wow
+  - 8675309
+map:
+  - key: value
+  - key2: "value 2"
+  - key3: 'value 3'
+whatever_this_is: [i imagine, it's, a, sequence?]"#,
+            ),
+        )
+        .unwrap();
+
+        let vfs = Vfs::new(imfs.clone());
+
+        let instance_snapshot = snapshot_yaml(
+            &InstanceContext::default(),
+            &vfs,
+            Path::new("/foo.yml"),
+            "foo",
+        )
+        .unwrap()
+        .unwrap();
+
+        insta::assert_yaml_snapshot!(instance_snapshot);
+    }
+}