feat(biome_js_analyze): align no_unused_private_class_members_with_semantic_class

.changeset/no_unused_private_class_members_amended.md

@@ -0,0 +1,72 @@
+---
+"@biomejs/biome": patch
+---
+
+Changed [`noUnusedPrivateClassMembers`](https://biomejs.dev/linter/rules/no-unused-private-class-members/) to align more fully with meaningful reads.
+
+#### Invalid examples (previously valid)
+
+```ts
+class UsedMember {
+  get #usedAccessor() {}
+  set #usedAccessor(value) {}
+
+  method() {
+    // no return statement so no meaningful read
+    this.#usedAccessor = 42;
+  }
+}
+
+class UsedMember {
+  #usedInInnerClass;
+
+  method(a) {
+    return class {
+      // not really used, a is not reference to this scope
+      foo = a.#usedInInnerClass;
+    }
+  }
+}
+
+class UsedMember {
+  set #accessorUsedInMemberAccess(value) {} // <- unused
+
+  method(a) {
+    // there is no getter, so this is not a read at all
+    [this.#accessorUsedInMemberAccess] = a;
+  }
+}
+
+class UsedMember {
+  #usedInInnerClass;
+
+  method(a) {
+    return class {
+      foo = a.#usedInInnerClass;
+    }
+  }
+}
+
+class C {
+  set #x(value) {
+    doSomething(value);
+  }
+
+  foo() {
+    // no return statement so not a meaningful read.
+    this.#x = 1;
+  }
+}
+```
+
+#### Valid example (Previously invalid)
+
+```js
+class Foo {
+  #usedOnlyInWriteStatement = 5;
+  method() {
+    // this is both meaningful read and write.
+    this.#usedOnlyInWriteStatement += 42;
+  }
+}
+```