1 files changed, 73 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/debug/Memory-takeCensus-08.js b/js/src/jit-test/tests/debug/Memory-takeCensus-08.js
new file mode 100644
index 000000000..637f0d059
--- /dev/null
+++ b/js/src/jit-test/tests/debug/Memory-takeCensus-08.js
@@ -0,0 +1,73 @@
+// Debugger.Memory.prototype.takeCensus: test by: 'count' breakdown
+
+let g = newGlobal();
+let dbg = new Debugger(g);
+
+g.eval(`
+       var stuff = [];
+       function add(n, c) {
+         for (let i = 0; i < n; i++)
+           stuff.push(c());
+       }
+
+       let count = 0;
+
+       function obj() { return { count: count++ }; }
+       obj.factor = 1;
+
+       // This creates a closure (a function JSObject) that has captured
+       // a Call object. So each call creates two items.
+       function fun() { let v = count; return () => { return v; } }
+       fun.factor = 2;
+
+       function str() { return 'perambulator' + count++; }
+       str.factor = 1;
+
+       // Eval a fresh text each time, allocating:
+       // - a fresh ScriptSourceObject
+       // - a new JSScripts, not an eval cache hits
+       // - a fresh prototype object
+       // - a fresh Call object, since the eval makes 'ev' heavyweight
+       // - the new function itself
+       function ev()  {
+         return eval(\`(function () { return \${ count++ } })\`);
+       }
+       ev.factor = 5;
+
+       // A new object (1) with a new shape (2) with a new atom (3)
+       function shape() { return { [ 'theobroma' + count++ ]: count }; }
+       shape.factor = 3;
+       `);
+
+let baseline = 0;
+function countIncreasedByAtLeast(n) {
+  let oldBaseline = baseline;
+
+  // Since a census counts only reachable objects, one might assume that calling
+  // GC here would have no effect on the census results. But GC also throws away
+  // JIT code and any objects it might be holding (template objects, say);
+  // takeCensus reaches those. Shake everything loose that we can, to make the
+  // census approximate reachability a bit more closely, and make our results a
+  // bit more predictable.
+  gc(g, 'shrinking');
+
+  baseline = dbg.memory.takeCensus({ breakdown: { by: 'count' } }).count;
+  return baseline >= oldBaseline + n;
+}
+
+countIncreasedByAtLeast(0);
+
+g.add(100, g.obj);
+assertEq(countIncreasedByAtLeast(g.obj.factor * 100), true);
+
+g.add(100, g.fun);
+assertEq(countIncreasedByAtLeast(g.fun.factor * 100), true);
+
+g.add(100, g.str);
+assertEq(countIncreasedByAtLeast(g.str.factor * 100), true);
+
+g.add(100, g.ev);
+assertEq(countIncreasedByAtLeast(g.ev.factor * 100), true);
+
+g.add(100, g.shape);
+assertEq(countIncreasedByAtLeast(g.shape.factor * 100), true);