Initial ArrayBuffer implementation; Conditional allocation within constructors; Explicit constructor return values

tests/compiler/std/constructor.ts

@@ -0,0 +1,86 @@
+import "allocator/arena";
+
+// trailing conditional allocate
+class EmptyCtor {
+  constructor() {}
+}
+
+var emptyCtor = new EmptyCtor();
+
+// trailing conditional allocate with field initializer
+class EmptyCtorWithFieldInit {
+  a: i32 = 1;
+  constructor() {}
+}
+
+var emptyCtorWithFieldInit = new EmptyCtorWithFieldInit();
+
+// trailing conditional allocate with field initialized to zero
+class EmptyCtorWithFieldNoInit {
+  a: i32;
+  constructor() {}
+}
+
+var emptyCtorWithFieldNoInit = new EmptyCtorWithFieldNoInit();
+
+// direct allocate
+class None {
+}
+
+var none = new None();
+
+// direct allocate with field initializer
+class JustFieldInit {
+  a: i32 = 1;
+}
+
+var justFieldInit = new JustFieldInit();
+
+// direct allocate with field initialized to zero
+class JustFieldNoInit {
+  a: i32;
+}
+
+var justFieldNoInit = new JustFieldNoInit();
+
+// explicit allocation with no extra checks
+class CtorReturns {
+  constructor() {
+    return changetype<CtorReturns>(allocate_memory(0));
+  }
+}
+
+var ctorReturns = new CtorReturns();
+
+var b: bool = true;
+
+// explicit allocation with a trailing conditional fallback
+class CtorConditionallyReturns {
+  constructor() {
+    if (b) {
+      return changetype<CtorConditionallyReturns>(allocate_memory(0));
+    }
+  }
+}
+
+var ctorConditionallyReturns = new CtorConditionallyReturns();
+
+// implicit allocation with no extra checks
+class CtorAllocates {
+  constructor() {
+    this;
+  }
+}
+
+var ctorAllocates = new CtorAllocates();
+
+// implicit allocation with a trailing conditional fallback
+class CtorConditionallyAllocates {
+  constructor() {
+    if (b) {
+      this;
+    }
+  }
+}
+
+var ctorConditionallyAllocates = new CtorConditionallyAllocates();