Implement sourcemap CLI command (#530)

* Initial implementation of sourcemap CLI command

* Update src/cli/sourcemap.rs

Co-authored-by: JohnnyMorganz <johnnymorganz@outlook.com>

* Update src/cli/sourcemap.rs

Co-authored-by: JohnnyMorganz <johnnymorganz@outlook.com>

* Tidy up sourcemap command

* Update CHANGELOG

Co-authored-by: JohnnyMorganz <johnnymorganz@outlook.com>
Co-authored-by: Lucien Greathouse <me@lpghatguy.com>

CHANGELOG.md

@@ -3,9 +3,11 @@
 ## Unreleased Changes
 * Added support for specifying an address to be used by default in the .project.json file ([#447])
 * Added support for the new Open Cloud API when uploading. ([#486])
+* Added `sourcemap` command for generating sourcemaps to feed into other tools. ([#530])
 
 [#447]: https://github.com/rojo-rbx/rojo/issues/447
 [#486]: https://github.com/rojo-rbx/rojo/issues/486
+[#530]: https://github.com/rojo-rbx/rojo/pull/530
 
 ## [7.0.0] - December 10, 2021
 * Fixed Rojo's interactions with properties enabled by FFlags that are not yet enabled. ([#493])
@@ -480,4 +482,4 @@ This is a general maintenance release for the Rojo 0.5.x release series.
 * More robust syncing with a new reconciler
 
 ## [0.1.0](https://github.com/rojo-rbx/rojo/releases/tag/v0.1.0) (November 29, 2017)
-* Initial release, functionally very similar to [rbxfs](https://github.com/LPGhatguy/rbxfs)
+* Initial release, functionally very similar to [rbxfs](https://github.com/LPGhatguy/rbxfs)

src/cli/mod.rs

@@ -6,6 +6,7 @@ mod fmt_project;
 mod init;
 mod plugin;
 mod serve;
+mod sourcemap;
 mod upload;
 
 use std::{borrow::Cow, env, path::Path, str::FromStr};
@@ -19,6 +20,7 @@ pub use self::fmt_project::FmtProjectCommand;
 pub use self::init::{InitCommand, InitKind};
 pub use self::plugin::{PluginCommand, PluginSubcommand};
 pub use self::serve::ServeCommand;
+pub use self::sourcemap::SourcemapCommand;
 pub use self::upload::UploadCommand;
 
 /// Command line options that Rojo accepts, defined using the structopt crate.
@@ -40,6 +42,7 @@ impl Options {
             Subcommand::Serve(subcommand) => subcommand.run(self.global),
             Subcommand::Build(subcommand) => subcommand.run(),
             Subcommand::Upload(subcommand) => subcommand.run(),
+            Subcommand::Sourcemap(subcommand) => subcommand.run(),
             Subcommand::FmtProject(subcommand) => subcommand.run(),
             Subcommand::Doc(subcommand) => subcommand.run(),
             Subcommand::Plugin(subcommand) => subcommand.run(),
@@ -112,6 +115,7 @@ pub enum Subcommand {
     Serve(ServeCommand),
     Build(BuildCommand),
     Upload(UploadCommand),
+    Sourcemap(SourcemapCommand),
     FmtProject(FmtProjectCommand),
     Doc(DocCommand),
     Plugin(PluginCommand),

src/cli/sourcemap.rs

@@ -0,0 +1,139 @@
+use std::{
+    io::{BufWriter, Write},
+    path::{Path, PathBuf},
+};
+
+use fs_err::File;
+use memofs::Vfs;
+use rbx_dom_weak::types::Ref;
+use serde::Serialize;
+use structopt::StructOpt;
+
+use crate::{
+    serve_session::ServeSession,
+    snapshot::{InstanceWithMeta, RojoTree},
+};
+
+use super::resolve_path;
+
+const PATH_STRIP_FAILED_ERR: &str = "Failed to create relative paths for project file!";
+
+/// Representation of a node in the generated sourcemap tree.
+#[derive(Serialize)]
+#[serde(rename_all = "camelCase")]
+struct SourcemapNode {
+    name: String,
+    class_name: String,
+
+    #[serde(skip_serializing_if = "Vec::is_empty")]
+    file_paths: Vec<PathBuf>,
+
+    #[serde(skip_serializing_if = "Vec::is_empty")]
+    children: Vec<SourcemapNode>,
+}
+
+/// Generates a sourcemap file from the Rojo project.
+#[derive(Debug, StructOpt)]
+pub struct SourcemapCommand {
+    /// Path to the project to use for the sourcemap. Defaults to the current
+    /// directory.
+    #[structopt(default_value = "")]
+    pub project: PathBuf,
+
+    /// Where to output the sourcemap. Omit this to use stdout instead of
+    /// writing to a file.
+    ///
+    /// Should end in .json.
+    #[structopt(long, short)]
+    pub output: Option<PathBuf>,
+
+    /// If non-script files should be included or not. Defaults to false.
+    #[structopt(long)]
+    pub include_non_scripts: bool,
+}
+
+impl SourcemapCommand {
+    pub fn run(self) -> anyhow::Result<()> {
+        let project_path = resolve_path(&self.project);
+
+        let mut project_dir = project_path.to_path_buf();
+        project_dir.pop();
+
+        log::trace!("Constructing in-memory filesystem");
+        let vfs = Vfs::new_default();
+
+        let session = ServeSession::new(vfs, &project_path)?;
+        let tree = session.tree();
+
+        let filter = if self.include_non_scripts {
+            filter_nothing
+        } else {
+            filter_non_scripts
+        };
+
+        let root_node = recurse_create_node(&tree, tree.get_root_id(), &project_dir, filter);
+
+        if let Some(output_path) = self.output {
+            let mut file = BufWriter::new(File::create(&output_path)?);
+            serde_json::to_writer(&mut file, &root_node)?;
+            file.flush()?;
+
+            println!("Created sourcemap at {}", output_path.display());
+        } else {
+            let output = serde_json::to_string(&root_node)?;
+            println!("{}", output);
+        }
+
+        Ok(())
+    }
+}
+
+fn filter_nothing(_instance: &InstanceWithMeta) -> bool {
+    true
+}
+
+fn filter_non_scripts(instance: &InstanceWithMeta) -> bool {
+    match instance.class_name() {
+        "Script" | "LocalScript" | "ModuleScript" => true,
+        _ => false,
+    }
+}
+
+fn recurse_create_node(
+    tree: &RojoTree,
+    referent: Ref,
+    project_dir: &Path,
+    filter: fn(&InstanceWithMeta) -> bool,
+) -> Option<SourcemapNode> {
+    let instance = tree.get_instance(referent).expect("instance did not exist");
+
+    let mut children = Vec::new();
+    for &child_id in instance.children() {
+        if let Some(child_node) = recurse_create_node(tree, child_id, &project_dir, filter) {
+            children.push(child_node);
+        }
+    }
+
+    // If this object has no children and doesn't pass the filter, it doesn't
+    // contain any information we're looking for.
+    if children.is_empty() && !filter(&instance) {
+        return None;
+    }
+
+    let file_paths = instance
+        .metadata()
+        .relevant_paths
+        .iter()
+        // Not all paths listed as relevant are guaranteed to exist.
+        .filter(|path| path.is_file())
+        .map(|path| path.strip_prefix(project_dir).expect(PATH_STRIP_FAILED_ERR))
+        .map(|path| path.to_path_buf())
+        .collect();
+
+    Some(SourcemapNode {
+        name: instance.name().to_string(),
+        class_name: instance.class_name().to_string(),
+        file_paths,
+        children,
+    })
+}