Don't count identifier expressions as variable usages in StrictUnusedVariable check

baseline-error-prone/src/main/java/com/palantir/baseline/errorprone/StrictUnusedVariable.java

@@ -91,6 +91,7 @@
 import com.sun.source.tree.ReturnTree;
 import com.sun.source.tree.StatementTree;
 import com.sun.source.tree.Tree;
+import com.sun.source.tree.Tree.Kind;
 import com.sun.source.tree.TryTree;
 import com.sun.source.tree.UnaryTree;
 import com.sun.source.tree.VariableTree;
@@ -1054,7 +1055,9 @@ public Void visitIdentifier(IdentifierTree tree, Void unused) {
 
         @Override
         public Void visitMemberSelect(MemberSelectTree memberSelectTree, Void unused) {
-            usageSites.put(getSymbol(memberSelectTree), getCurrentPath());
+            if (!memberSelectTree.getExpression().getKind().equals(Kind.IDENTIFIER)) {
+                usageSites.put(getSymbol(memberSelectTree), getCurrentPath());
+            }
             return super.visitMemberSelect(memberSelectTree, null);
         }
     }

baseline-error-prone/src/test/java/com/palantir/baseline/errorprone/StrictUnusedVariableTest.java

@@ -80,6 +80,20 @@ public void handles_classes() {
                 .doTest();
     }
 
+    @Test
+    public void handles_classes_ignoresIdentifierExpressions() {
+        compilationHelper
+                .addSourceLines(
+                        "Test.java",
+                        "class Test {",
+                        "  private final String _field;",
+                        "  public Test(String value) {",
+                        "    this._field = value;",
+                        "  }",
+                        "}")
+                .doTest();
+    }
+
     @Test
     public void handles_enums() {
         compilationHelper

changelog/@unreleased/pr-2304.v2.yml

@@ -0,0 +1,6 @@
+type: fix
+fix:
+  description: Don't count identifier expressions as variable usages in `StrictUnusedVariable`
+    check
+  links:
+  - https://github.com/palantir/gradle-baseline/pull/2304