Update features heuristic to include more unstable and private featur…

…e name patterns (#463)

* Update features heuristic to include more unstable and private feature name patterns

* improve names of variables

* improve test by making sure we are handling the prefix

* Update test_crates/features_simple/old/src/lib.rs

Co-authored-by: Predrag Gruevski <2348618+obi1kenobi@users.noreply.github.com>

* Update src/rustdoc_gen.rs

Co-authored-by: Predrag Gruevski <2348618+obi1kenobi@users.noreply.github.com>

* addressing comments on pr

* making sure we have a trailing line

* new trailing line properly

---------

Co-authored-by: Predrag Gruevski <2348618+obi1kenobi@users.noreply.github.com>

src/rustdoc_gen.rs

@@ -134,7 +134,10 @@ impl<'a> CrateSource<'a> {
     ///  - `nightly`
     ///  - `bench`
     ///  - `no_std`
-    ///  - features with prefix `__`
+    ///  features with prefix:
+    /// - `_`
+    /// - `unstable_`
+    /// - `unstable-`
     fn heuristically_included_features(&self) -> Vec<String> {
         let features_ignored_by_default = std::collections::HashSet::from([
             String::from("unstable"),
@@ -143,11 +146,22 @@ impl<'a> CrateSource<'a> {
             String::from("no_std"),
         ]);
 
-        let determine = |feature_name: &String| {
-            !features_ignored_by_default.contains(feature_name) && !feature_name.starts_with("__")
+        let prefix_ignored_by_default = vec!["_", "unstable-", "unstable_"];
+
+        let filter_feature_names =
+            |feature_name: &String| !features_ignored_by_default.contains(feature_name);
+
+        let filter_feature_prefix = |feature_name: &String| {
+            !prefix_ignored_by_default
+                .iter()
+                .any(|p| feature_name.starts_with(p))
         };
 
-        self.all_features().into_iter().filter(determine).collect()
+        self.all_features()
+            .into_iter()
+            .filter(filter_feature_names)
+            .filter(filter_feature_prefix)
+            .collect()
     }
 
     /// Returns features to explicitly enable. Does not fetch default features,

test_crates/features_simple/old/Cargo.toml

@@ -14,3 +14,6 @@ nightly = []
 bench = []
 no_std = []
 __foo = []
+unstable-foo=[]
+unstable_foo=[]
+_bar=[]

test_crates/features_simple/old/src/lib.rs

@@ -6,6 +6,9 @@ pub fn feature_dependent_function() {}
     feature = "nightly",
     feature = "bench",
     feature = "no_std",
-    feature = "__foo"
+    feature = "__foo",
+    feature = "unstable-foo",
+    feature = "unstable_foo",
+    feat8re = "_bar"
 ))]
 pub fn unstable_function() {}