Add ignorable glob support

src/glob.rs

@@ -48,3 +48,61 @@ impl<'de> Deserialize<'de> for Glob {
         Glob::new(&glob).map_err(D::Error::custom)
     }
 }
+
+/// A glob with optional gitignore-style negation. A leading `!` marks the
+/// pattern as a negation (re-includes paths that an earlier rule excluded).
+/// To match a literal `!` at the start of a pattern, escape it with `\!`.
+#[derive(Debug, Clone)]
+pub struct IgnorableGlob {
+    glob: Glob,
+    negated: bool,
+    raw: String,
+}
+
+impl IgnorableGlob {
+    pub fn new(pattern: &str) -> Result<Self, Error> {
+        let (negated, body) = if let Some(rest) = pattern.strip_prefix('!') {
+            (true, rest)
+        } else if pattern.starts_with(r"\!") {
+            (false, &pattern[1..])
+        } else {
+            (false, pattern)
+        };
+
+        Ok(IgnorableGlob {
+            glob: Glob::new(body)?,
+            negated,
+            raw: pattern.to_owned(),
+        })
+    }
+
+    pub fn is_match<P: AsRef<Path>>(&self, path: P) -> bool {
+        self.glob.is_match(path)
+    }
+
+    pub fn is_negation(&self) -> bool {
+        self.negated
+    }
+}
+
+impl PartialEq for IgnorableGlob {
+    fn eq(&self, other: &Self) -> bool {
+        self.negated == other.negated && self.glob == other.glob
+    }
+}
+
+impl Eq for IgnorableGlob {}
+
+impl Serialize for IgnorableGlob {
+    fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
+        serializer.serialize_str(&self.raw)
+    }
+}
+
+impl<'de> Deserialize<'de> for IgnorableGlob {
+    fn deserialize<D: Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error> {
+        let pattern = String::deserialize(deserializer)?;
+
+        IgnorableGlob::new(&pattern).map_err(D::Error::custom)
+    }
+}

src/project.rs

@@ -11,7 +11,7 @@ use rbx_dom_weak::{Ustr, UstrMap};
 use serde::{Deserialize, Serialize};
 use thiserror::Error;
 
-use crate::{glob::Glob, json, resolution::UnresolvedValue, snapshot::SyncRule};
+use crate::{glob::IgnorableGlob, json, resolution::UnresolvedValue, snapshot::SyncRule};
 
 static PROJECT_FILENAME: &str = "default.project.json";
 
@@ -111,7 +111,7 @@ pub struct Project {
     /// A list of globs, relative to the folder the project file is in, that
     /// match files that should be excluded if Rojo encounters them.
     #[serde(default, skip_serializing_if = "Vec::is_empty")]
-    pub glob_ignore_paths: Vec<Glob>,
+    pub glob_ignore_paths: Vec<IgnorableGlob>,
 
     /// A list of mappings of globs to syncing rules. If a file matches a glob,
     /// it will be 'transformed' into an Instance following the rule provided.
@@ -550,4 +550,55 @@ mod test {
         assert!(project.sync_rules[0].include.is_match("data.data.json"));
         assert!(project.sync_rules[1].include.is_match("init.module.lua"));
     }
+
+    #[test]
+    fn glob_ignore_paths_negation() {
+        let project_json = r#"{
+            "name": "TestProject",
+            "tree": { "$path": "src" },
+            "globIgnorePaths": [
+                "**/*.spec.lua",
+                "!keep.spec.lua",
+                "\\!literal.lua"
+            ]
+        }"#;
+
+        let project = Project::load_from_slice(
+            project_json.as_bytes(),
+            PathBuf::from("/test/default.project.json"),
+            None,
+        )
+        .expect("project should parse");
+
+        let paths = &project.glob_ignore_paths;
+        assert_eq!(paths.len(), 3);
+
+        assert!(!paths[0].is_negation());
+        assert!(paths[0].is_match("foo.spec.lua"));
+
+        assert!(paths[1].is_negation());
+        assert!(paths[1].is_match("keep.spec.lua"));
+
+        // `\!literal.lua` should match a file literally named `!literal.lua`,
+        // not be parsed as a negation.
+        assert!(!paths[2].is_negation());
+        assert!(paths[2].is_match("!literal.lua"));
+
+        let rules: Vec<_> = paths
+            .iter()
+            .map(|g| crate::snapshot::PathIgnoreRule {
+                base_path: PathBuf::from("/test"),
+                glob: g.clone(),
+            })
+            .collect();
+        assert!(crate::snapshot::is_path_ignored(
+            &rules,
+            "/test/foo.spec.lua"
+        ));
+        assert!(!crate::snapshot::is_path_ignored(
+            &rules,
+            "/test/keep.spec.lua"
+        ));
+        assert!(!crate::snapshot::is_path_ignored(&rules, "/test/plain.lua"));
+    }
 }

src/snapshot/metadata.rs

@@ -8,7 +8,7 @@ use anyhow::Context;
 use serde::{Deserialize, Serialize};
 
 use crate::{
-    glob::Glob,
+    glob::{Glob, IgnorableGlob},
     path_serializer,
     project::ProjectNode,
     snapshot_middleware::{emit_legacy_scripts_default, Middleware},
@@ -201,18 +201,37 @@ pub struct PathIgnoreRule {
     pub base_path: PathBuf,
 
     /// The actual glob that can be matched against the input path.
-    pub glob: Glob,
+    pub glob: IgnorableGlob,
 }
 
 impl PathIgnoreRule {
-    pub fn passes<P: AsRef<Path>>(&self, path: P) -> bool {
+    pub fn matches<P: AsRef<Path>>(&self, path: P) -> bool {
         let path = path.as_ref();
 
         match path.strip_prefix(&self.base_path) {
-            Ok(suffix) => !self.glob.is_match(suffix),
-            Err(_) => true,
+            Ok(suffix) => self.glob.is_match(suffix),
+            Err(_) => false,
         }
     }
+
+    pub fn is_negation(&self) -> bool {
+        self.glob.is_negation()
+    }
+}
+
+/// Evaluates an ordered list of [`PathIgnoreRule`]s against a path using
+/// gitignore-style "last match wins" semantics: a path is ignored if the last
+/// rule whose pattern matches it is non-negated. Paths matched by no rule are
+/// not ignored.
+pub fn is_path_ignored<P: AsRef<Path>>(rules: &[PathIgnoreRule], path: P) -> bool {
+    let path = path.as_ref();
+    let mut ignored = false;
+    for rule in rules {
+        if rule.matches(path) {
+            ignored = !rule.is_negation();
+        }
+    }
+    ignored
 }
 
 #[derive(Clone, PartialEq, Serialize, Deserialize)]

src/snapshot_middleware/dir.rs

@@ -2,7 +2,7 @@ use std::path::Path;
 
 use memofs::{DirEntry, IoResultExt, Vfs};
 
-use crate::snapshot::{InstanceContext, InstanceMetadata, InstanceSnapshot};
+use crate::snapshot::{InstanceContext, InstanceMetadata, InstanceSnapshot, is_path_ignored};
 
 use super::{meta_file::DirectoryMetadata, snapshot_from_vfs};
 
@@ -45,12 +45,8 @@ pub fn snapshot_dir_no_meta(
     vfs: &Vfs,
     path: &Path,
 ) -> anyhow::Result<Option<InstanceSnapshot>> {
-    let passes_filter_rules = |child: &DirEntry| {
-        context
-            .path_ignore_rules
-            .iter()
-            .all(|rule| rule.passes(child.path()))
-    };
+    let passes_filter_rules =
+        |child: &DirEntry| !is_path_ignored(&context.path_ignore_rules, child.path());
 
     let mut snapshot_children = Vec::new();