Port commands to use common setup code

Initialization logic needed for serve, build, and upload is now
much more clear than it was when these functions were written.

This commit refactors all of them to use a new common_setup
module for all of their initialization that's the same.

src/commands/build.rs

@@ -1,18 +1,15 @@
 use std::{
-    collections::HashMap,
     fs::File,
     io::{self, BufWriter, Write},
     path::PathBuf,
 };
 
 use failure::Fail;
-use rbx_dom_weak::RbxInstanceProperties;
 
 use crate::{
+    common_setup,
     imfs::{FsError, Imfs, RealFetcher, WatchMode},
-    project::{Project, ProjectLoadError},
-    snapshot::{apply_patch_set, compute_patch_set, InstancePropertiesWithMeta, RojoTree},
-    snapshot_middleware::{snapshot_from_imfs, InstanceSnapshotContext, SnapshotPluginContext},
+    project::ProjectLoadError,
 };
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
@@ -83,52 +80,11 @@ pub fn build(options: &BuildOptions) -> Result<(), BuildError> {
 
     log::debug!("Hoping to generate file of type {:?}", output_kind);
 
-    let maybe_project = match Project::load_fuzzy(&options.fuzzy_project_path) {
-        Ok(project) => Some(project),
-        Err(ProjectLoadError::NotFound) => None,
-        Err(other) => return Err(other.into()),
-    };
-    log::trace!("Using project file {:#?}", maybe_project);
-
-    let mut tree = RojoTree::new(InstancePropertiesWithMeta {
-        properties: RbxInstanceProperties {
-            name: "ROOT".to_owned(),
-            class_name: "Folder".to_owned(),
-            properties: HashMap::new(),
-        },
-        metadata: Default::default(),
-    });
-    let root_id = tree.get_root_id();
-
     log::trace!("Constructing in-memory filesystem");
     let mut imfs = Imfs::new(RealFetcher::new(WatchMode::Disabled));
 
-    log::trace!("Reading project root");
-    let entry = imfs
-        .get(&options.fuzzy_project_path)
-        .expect("could not get project path");
-
-    let mut snapshot_context = InstanceSnapshotContext::default();
-
-    if let Some(project) = maybe_project {
-        // If the project file defines no plugins, then there's no need to
-        // initialize the snapshot plugin context.
-        if !project.plugins.is_empty() {
-            snapshot_context.plugin_context =
-                Some(SnapshotPluginContext::new(project.plugins.clone()));
-        }
-    }
-
-    log::trace!("Generating snapshot of instances from IMFS");
-    let snapshot = snapshot_from_imfs(&mut snapshot_context, &mut imfs, &entry)
-        .expect("snapshot failed")
-        .expect("snapshot did not return an instance");
-
-    log::trace!("Computing patch set");
-    let patch_set = compute_patch_set(&snapshot, &tree, root_id);
-
-    log::trace!("Applying patch set");
-    apply_patch_set(&mut tree, patch_set);
+    let (_maybe_project, tree) = common_setup::start(&options.fuzzy_project_path, &mut imfs);
+    let root_id = tree.get_root_id();
 
     log::trace!("Opening output file for write");
     let mut file = BufWriter::new(File::create(&options.output_file)?);