Remove duplicate source entries

Author: bioball

pkl-core/src/main/java/org/pkl/core/runtime/PowerAssertions.java

@@ -24,6 +24,7 @@
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.Deque;
+import java.util.LinkedHashSet;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
@@ -208,10 +209,12 @@ private static boolean shouldHide(
     return null;
   }
 
-  private static List<LayerEntry> getLayerEntries(
+  private static Collection<LayerEntry> getLayerEntries(
       Map<Node, List<Object>> trackedValues, SourceSection sourceSection) {
     var exprNode = parser.parseExpressionInput(sourceSection.getCharacters().toString());
-    var ret = new ArrayList<LayerEntry>();
+    // it's possible that two nodes can turn into identical `SourceEntry`s; ensure these entries are
+    // distinct by using a set.
+    var ret = new LinkedHashSet<LayerEntry>();
     for (var entry : trackedValues.entrySet()) {
       var truffleNode = entry.getKey();
       var values = entry.getValue();
@@ -250,7 +253,7 @@ private static boolean canFitMarker(Deque<LayerEntry> layer, LayerEntry elem) {
   }
 
   private static List<Collection<LayerEntry>> buildLayers(
-      List<LayerEntry> layerEntries, SourceSection line) {
+      Collection<LayerEntry> layerEntries, SourceSection line) {
     var sortedSections =
         layerEntries.stream()
             .filter((it) -> it.startLine() == line.getStartLine())
@@ -339,7 +342,7 @@ private static boolean renderLine(
       AnsiStringBuilder out,
       String indent,
       SourceSection line,
-      List<LayerEntry> layerEntries,
+      Collection<LayerEntry> layerEntries,
       int trimStart,
       @Nullable Consumer<AnsiStringBuilder> lineSuffix) {
     var layers = buildLayers(layerEntries, line);

pkl-core/src/test/files/LanguageSnippetTests/input/errors/power/typeConstraints16.pkl

@@ -0,0 +1,10 @@
+class Bird {
+  name: String?
+}
+
+// this will create `NullPropagatingOperationNode` and `InvokeVirtualMethodNode` for
+// `name?.contains("Bob")`.
+// this tests that we don't have two duplicate values in the diagram.
+p: Bird(name?.contains("Bob") ?? false) = new {
+  name = "Pigeon"
+}

pkl-core/src/test/files/LanguageSnippetTests/output/errors/power/typeConstraints16.err

@@ -0,0 +1,20 @@
+–– Pkl Error ––
+Type constraint `name?.contains("Bob") ?? false` violated.
+Value: new Bird { name = "Pigeon" }
+
+    name?.contains("Bob") ?? false
+    |     |               |
+    |     false           false
+    "Pigeon"
+
+x | p: Bird(name?.contains("Bob") ?? false) = new {
+            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+at typeConstraints16#p (file:///$snippetsDir/input/errors/power/typeConstraints16.pkl)
+
+xxx | renderer.renderDocument(value)
+      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+at pkl.base#Module.output.text (pkl:base)
+
+xxx | if (renderer is BytesRenderer) renderer.renderDocument(value) else text.encodeToBytes("UTF-8")
+                                                                         ^^^^
+at pkl.base#Module.output.bytes (pkl:base)