Merge pull request #4752 from 219sansim:fix_flaky_LatticeRelation

[core] Fix flaky LatticeRelationTest #4752

docs/pages/release_notes.md

@@ -415,6 +415,7 @@ See [Detailed Release Notes for PMD 7.0.0]({{ baseurl }}pmd_release_notes_pmd7.h
 * [#4738](https://github.com/pmd/pmd/pull/4738): \[doc] Added reference to the PMD extension for bld - [Erik C. Thauvin](https://github.com/ethauvin) (@ethauvin)
 * [#4749](https://github.com/pmd/pmd/pull/4749):   Fixes NoSuchMethodError on processing errors in pmd-compat6 - [Andreas Bergander](https://github.com/bergander) (@bergander)
 * [#4750](https://github.com/pmd/pmd/pull/4750): \[core] Fix flaky SummaryHTMLRenderer - [219sansim](https://github.com/219sansim) (@219sansim)
+* [#4752](https://github.com/pmd/pmd/pull/4752): \[core] Fix flaky LatticeRelationTest - [219sansim](https://github.com/219sansim) (@219sansim)
 * [#4754](https://github.com/pmd/pmd/pull/4754): \[java] EmptyControlStatementRule: Add allowCommentedBlocks property - [Andreas Bergander](https://github.com/bergander) (@bergander)
 * [#4759](https://github.com/pmd/pmd/pull/4759): \[java] fix: remove delimiter attribute from ruleset category/java/errorprone.xml - [Marcin Dąbrowski](https://github.com/marcindabrowski) (@marcindabrowski)
 * [#4825](https://github.com/pmd/pmd/pull/4825): \[plsql] Fix ignored WITH clause for SELECT INTO statements - [Laurent Bovet](https://github.com/lbovet) (@lbovet)
@@ -1223,6 +1224,7 @@ Language specific fixes:
 * [#4738](https://github.com/pmd/pmd/pull/4738): \[doc] Added reference to the PMD extension for bld - [Erik C. Thauvin](https://github.com/ethauvin) (@ethauvin)
 * [#4749](https://github.com/pmd/pmd/pull/4749):   Fixes NoSuchMethodError on processing errors in pmd-compat6 - [Andreas Bergander](https://github.com/bergander) (@bergander)
 * [#4750](https://github.com/pmd/pmd/pull/4750): \[core] Fix flaky SummaryHTMLRenderer - [219sansim](https://github.com/219sansim) (@219sansim)
+* [#4752](https://github.com/pmd/pmd/pull/4752): \[core] Fix flaky LatticeRelationTest - [219sansim](https://github.com/219sansim) (@219sansim)
 * [#4754](https://github.com/pmd/pmd/pull/4754): \[java] EmptyControlStatementRule: Add allowCommentedBlocks property - [Andreas Bergander](https://github.com/bergander) (@bergander)
 * [#4759](https://github.com/pmd/pmd/pull/4759): \[java] fix: remove delimiter attribute from ruleset category/java/errorprone.xml - [Marcin Dąbrowski](https://github.com/marcindabrowski) (@marcindabrowski)
 * [#4825](https://github.com/pmd/pmd/pull/4825): \[plsql] Fix ignored WITH clause for SELECT INTO statements - [Laurent Bovet](https://github.com/lbovet) (@lbovet)

pmd-core/src/main/java/net/sourceforge/pmd/util/GraphUtil.java

@@ -43,7 +43,9 @@ public final class GraphUtil {
         StringBuilder sb = new StringBuilder("strict digraph {\n");
         Map<V, String> ids = new HashMap<>();
         int i = 0;
-        for (V node : vertices) {
+        List<V> vertexList = new ArrayList<>(vertices);
+        vertexList.sort(Comparator.comparing(Object::toString)); // for reproducibility in tests
+        for (V node : vertexList) {
             String id = "n" + i++;
             ids.put(node, id);
             sb.append(id)
@@ -56,7 +58,7 @@ public final class GraphUtil {
 
         List<String> edges = new ArrayList<>();
 
-        for (V node : vertices) {
+        for (V node : vertexList) {
             // edges
             String id = ids.get(node);
             for (V succ : successorFun.apply(node)) {

pmd-core/src/test/java/net/sourceforge/pmd/lang/rule/internal/LatticeRelationTest.java

@@ -279,15 +279,15 @@ class LatticeRelationTest {
         // all {1}, {2}, and { } are query nodes, not {1,2}
 
         assertEquals("strict digraph {\n"
-                         + "n0 [ shape=box, color=green, label=\"[]\" ];\n"
+                         + "n0 [ shape=box, color=black, label=\"[1, 2]\" ];\n"
                          + "n1 [ shape=box, color=green, label=\"[1]\" ];\n"
                          + "n2 [ shape=box, color=green, label=\"[2]\" ];\n"
-                         + "n3 [ shape=box, color=black, label=\"[1, 2]\" ];\n"
+                         + "n3 [ shape=box, color=green, label=\"[]\" ];\n"
-                         + "n1 -> n0;\n" // {1}   -> { }
+                         + "n0 -> n1;\n" // {1}   -> { }
-                         + "n2 -> n0;\n" // {2}   -> { }
+                         + "n0 -> n2;\n" // {2}   -> { }
-                         + "n3 -> n0;\n" // {1,2} -> { }
+                         + "n0 -> n3;\n" // {1,2} -> { }
-                         + "n3 -> n1;\n" // {1,2} -> {1}
+                         + "n1 -> n3;\n" // {1,2} -> {1}
-                         + "n3 -> n2;\n" // {1,2} -> {2}
+                         + "n2 -> n3;\n" // {1,2} -> {2}
                          + "}", lattice.toString());
     }