Remove duplicated code and tests across the engine, bench unchanged

arche-core/src/bench.rs

@@ -56,6 +56,16 @@ pub struct Position {
     pub operations: HashMap<String, String>,
 }
 
+impl Position {
+    /// The position as a board. A suite is read from a committed file, so a
+    /// fen that does not parse is a broken suite and panics, naming the
+    /// instrument that was reading it.
+    pub fn board(&self, instrument: &str) -> Board {
+        Board::from_fen(&self.fen)
+            .unwrap_or_else(|e| panic!("{} position {} does not parse: {}", instrument, self.id, e))
+    }
+}
+
 pub fn positions() -> Vec<Position> {
     parse_epd(SUITE)
 }
@@ -245,9 +255,7 @@ fn run(
     let positions = positions
         .iter()
         .map(|position| {
-            let board = Board::from_fen(&position.fen)
-                .unwrap_or_else(|e| panic!("bench position {} does not parse: {}", position.id, e));
-            let mut engine = AlphaBeta::with_config(board, table_bytes, config);
+            let mut engine = AlphaBeta::with_config(position.board("bench"), table_bytes, config);
             if audit && !engine.audit_signatures() {
                 return None;
             }
@@ -294,7 +302,9 @@ fn run(
     })
 }
 
-fn share(part: u64, whole: u64) -> f64 {
+/// A part as a percentage of the whole, and zero where there is no whole.
+/// The strategic suite's shares are taken the same way.
+pub(crate) fn share(part: u64, whole: u64) -> f64 {
     if whole == 0 {
         0.0
     } else {
@@ -685,6 +695,8 @@ mod tests {
         }
     }
 
+    /// Two audited runs of it count the same, since the audit reads the
+    /// search and nothing about the run.
     #[test]
     fn an_audited_run_searches_the_same_tree() {
         let suite = small_suite();
@@ -700,6 +712,9 @@ mod tests {
                 .collect::<Vec<_>>()
         };
         assert_eq!(played(&plain), played(&audited));
+        let again = run_audited_suite(&suite, Reach::Depth(4), 4 << 20, SearchConfig::default())
+            .expect("the keys");
+        assert_eq!(audited.signatures(), again.signatures());
     }
 
     /// The false accepts are pinned at zero rather than bounded. The
@@ -797,16 +812,6 @@ mod tests {
         assert!(none.narrow().all(|(_, _, expected)| expected == 0.0));
     }
 
-    #[test]
-    fn two_audited_runs_count_the_same() {
-        let suite = small_suite();
-        let first = run_audited_suite(&suite, Reach::Depth(4), 4 << 20, SearchConfig::default())
-            .expect("keys");
-        let second = run_audited_suite(&suite, Reach::Depth(4), 4 << 20, SearchConfig::default())
-            .expect("keys");
-        assert_eq!(first.signatures(), second.signatures());
-    }
-
     /// A deliberate change to the search is expected to move these: update
     /// them in the same commit, from `arche bench`, so the diff states how
     /// much of each tree the engine now looks at.