Move instigating source out of contributing paths (#253)

* Refactor contributing_paths into contributing_sources, deleting project node sources

* Instead of changing contributing_paths, add instigating_source

* Remove InstanceMetadata::project_node

* Stop pushing project path to front of contributing_paths since it doesn't matter now

* Remove accidental UI change for path display

src/snapshot/metadata.rs

@@ -1,4 +1,4 @@
-use std::path::PathBuf;
+use std::{fmt, path::PathBuf};
 
 use serde::{Deserialize, Serialize};
 
@@ -13,48 +13,64 @@ pub struct InstanceMetadata {
     /// manage.
     pub ignore_unknown_instances: bool,
 
+    /// If a change occurs to this instance, the instigating source is what
+    /// should be run through the snapshot functions to regenerate it.
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub instigating_source: Option<InstigatingSource>,
+
     /// The paths that, when changed, could cause the function that generated
     /// this snapshot to generate a different snapshot. Paths should be included
     /// even if they don't exist, since the presence of a file can change the
     /// outcome of a snapshot function.
     ///
-    /// The first path in this  list is considered the "instigating path", and
-    /// will be the snapshot target if any of the contributing paths change.
-    ///
     /// For example, a file named foo.lua might have these contributing paths:
-    /// - foo.lua (instigating path)
+    /// - foo.lua
     /// - foo.meta.json (even if this file doesn't exist!)
     ///
-    /// A directory named bar/ included in the project file might have these:
-    /// - bar/ (instigating path)
+    /// A directory named bar/ might have these:
+    /// - bar/
     /// - bar/init.meta.json
     /// - bar/init.lua
     /// - bar/init.server.lua
     /// - bar/init.client.lua
-    /// - default.project.json
+    /// - bar/default.project.json
     ///
     /// This path is used to make sure that file changes update all instances
     /// that may need updates.
     // TODO: Change this to be a SmallVec for performance in common cases?
     #[serde(serialize_with = "path_serializer::serialize_vec_absolute")]
     pub contributing_paths: Vec<PathBuf>,
-
-    /// If this instance was defined in a project file, this is the name from
-    /// the project file and the node under it.
-    ///
-    /// This information is used to make sure the instance has the correct name,
-    /// project-added children, and metadata when it's updated in response to a
-    /// file change.
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub project_node: Option<(String, ProjectNode)>,
 }
 
 impl Default for InstanceMetadata {
     fn default() -> Self {
         InstanceMetadata {
             ignore_unknown_instances: false,
+            instigating_source: None,
             contributing_paths: Vec::new(),
-            project_node: None,
         }
     }
 }
+
+#[derive(Clone, PartialEq, Serialize, Deserialize)]
+pub enum InstigatingSource {
+    Path(#[serde(serialize_with = "path_serializer::serialize_absolute")] PathBuf),
+    ProjectNode(String, ProjectNode),
+}
+
+impl fmt::Debug for InstigatingSource {
+    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            InstigatingSource::Path(path) => write!(formatter, "Path({})", path.display()),
+            InstigatingSource::ProjectNode(name, node) => {
+                write!(formatter, "ProjectNode({}: {:?}", name, node)
+            }
+        }
+    }
+}
+
+impl From<PathBuf> for InstigatingSource {
+    fn from(path: PathBuf) -> Self {
+        InstigatingSource::Path(path)
+    }
+}

src/snapshot/mod.rs

@@ -56,7 +56,7 @@ mod patch_compute;
 mod tree;
 
 pub use instance_snapshot::InstanceSnapshot;
-pub use metadata::InstanceMetadata;
+pub use metadata::*;
 pub use patch::*;
 pub use patch_apply::apply_patch_set;
 pub use patch_compute::compute_patch_set;