diff rust/hg-core/tests/test_missing_ancestors.rs @ 50979:4c5f6e95df84

rust: make `Revision` a newtype

This change is the one we've been building towards during this series.
The aim is to make `Revision` mean more than a simple integer, holding
the information that it is valid for a given revlog index.
While this still allows for programmer error, since creating a revision
directly and querying a different index with a "checked" revision are
still possible, the friction created by the newtype will hopefully make
us think twice about which type to use.

Enough of the Rust ecosystem relies on the newtype pattern to be
efficiently optimized away (even compiler in codegen tests¹), so I'm not
worried about this being a fundamental problem.

[1] https://github.com/rust-lang/rust/blob/7a70647f195f6b0a0f1ebd72b1542ba91a32f43a/tests/codegen/vec-in-place.rs#L47

--- a/rust/hg-core/tests/test_missing_ancestors.rs	Thu Aug 10 11:01:07 2023 +0200
+++ b/rust/hg-core/tests/test_missing_ancestors.rs	Fri Aug 18 14:34:29 2023 +0200
@@ -26,25 +26,28 @@
         if i == 0 || rng.gen_bool(rootprob) {
             vg.push([NULL_REVISION, NULL_REVISION])
         } else if i == 1 {
-            vg.push([0, NULL_REVISION])
+            vg.push([Revision(0), NULL_REVISION])
         } else if rng.gen_bool(mergeprob) {
             let p1 = {
                 if i == 2 || rng.gen_bool(prevprob) {
-                    (i - 1) as Revision
+                    Revision((i - 1) as BaseRevision)
                 } else {
-                    rng.gen_range(0..i - 1) as Revision
+                    Revision(rng.gen_range(0..i - 1) as BaseRevision)
                 }
             };
             // p2 is a random revision lower than i and different from p1
-            let mut p2 = rng.gen_range(0..i - 1) as Revision;
+            let mut p2 = Revision(rng.gen_range(0..i - 1) as BaseRevision);
             if p2 >= p1 {
-                p2 += 1;
+                p2.0 += 1;
             }
             vg.push([p1, p2]);
         } else if rng.gen_bool(prevprob) {
-            vg.push([(i - 1) as Revision, NULL_REVISION])
+            vg.push([Revision((i - 1) as BaseRevision), NULL_REVISION])
         } else {
-            vg.push([rng.gen_range(0..i - 1) as Revision, NULL_REVISION])
+            vg.push([
+                Revision(rng.gen_range(0..i - 1) as BaseRevision),
+                NULL_REVISION,
+            ])
         }
     }
     vg
@@ -55,10 +58,10 @@
     let mut ancs: Vec<HashSet<Revision>> = Vec::new();
     (0..vg.len()).for_each(|i| {
         let mut ancs_i = HashSet::new();
-        ancs_i.insert(i as Revision);
+        ancs_i.insert(Revision(i as BaseRevision));
         for p in vg[i].iter().cloned() {
             if p != NULL_REVISION {
-                ancs_i.extend(&ancs[p as usize]);
+                ancs_i.extend(&ancs[p.0 as usize]);
             }
         }
         ancs.push(ancs_i);
@@ -115,7 +118,7 @@
             .push(MissingAncestorsAction::RemoveAncestorsFrom(revs.clone()));
         for base in self.bases.iter().cloned() {
             if base != NULL_REVISION {
-                for rev in &self.ancestors_sets[base as usize] {
+                for rev in &self.ancestors_sets[base.0 as usize] {
                     revs.remove(rev);
                 }
             }
@@ -131,7 +134,7 @@
         let mut missing: HashSet<Revision> = HashSet::new();
         for rev in revs_as_set.iter().cloned() {
             if rev != NULL_REVISION {
-                missing.extend(&self.ancestors_sets[rev as usize])
+                missing.extend(&self.ancestors_sets[rev.0 as usize])
             }
         }
         self.history
@@ -139,7 +142,7 @@
 
         for base in self.bases.iter().cloned() {
             if base != NULL_REVISION {
-                for rev in &self.ancestors_sets[base as usize] {
+                for rev in &self.ancestors_sets[base.0 as usize] {
                     missing.remove(rev);
                 }
             }
@@ -193,10 +196,10 @@
     let sigma = sigma_opt.unwrap_or(0.8);
 
     let log_normal = LogNormal::new(mu, sigma).unwrap();
-    let nb = min(maxrev as usize, log_normal.sample(rng).floor() as usize);
+    let nb = min(maxrev.0 as usize, log_normal.sample(rng).floor() as usize);
 
-    let dist = Uniform::from(NULL_REVISION..maxrev);
-    rng.sample_iter(&dist).take(nb).collect()
+    let dist = Uniform::from(NULL_REVISION.0..maxrev.0);
+    rng.sample_iter(&dist).take(nb).map(Revision).collect()
 }
 
 /// Produces the hexadecimal representation of a slice of bytes
@@ -294,7 +297,7 @@
             eprintln!("Tested with {} graphs", g);
         }
         let graph = build_random_graph(None, None, None, None);
-        let graph_len = graph.len() as Revision;
+        let graph_len = Revision(graph.len() as BaseRevision);
         let ancestors_sets = ancestors_sets(&graph);
         for _testno in 0..testcount {
             let bases: HashSet<Revision> =