michael@0: // Setting a breakpoint in a generator function works, and we can
michael@0: // traverse the stack and evaluate expressions in the context of older
michael@0: // generator frames.
michael@0: 
michael@0: var g = newGlobal();
michael@0: var dbg = Debugger(g);
michael@0: dbg.onDebuggerStatement = function (frame) {
michael@0:     function hit(frame) {
michael@0:         assertEq(frame.generator, true);
michael@0:         assertEq(frame.older.generator, true);
michael@0:         frame.older.eval("q += 16");
michael@0:     }
michael@0: 
michael@0:     var s = frame.script;
michael@0:     var offs = s.getLineOffsets(g.line0 + 9);
michael@0:     for (var i = 0; i < offs.length; i++)
michael@0:         s.setBreakpoint(offs[i], {hit: hit});
michael@0: };
michael@0: 
michael@0: g.eval("line0 = Error().lineNumber;\n" +
michael@0:        "function* g(x) {\n" +   // + 1
michael@0:        "    var q = 10;\n" +    // + 2
michael@0:        "    yield* x;\n" +      // + 3
michael@0:        "    return q;\n" +      // + 4
michael@0:        "}\n" +                  // + 5
michael@0:        "function* range(n) {\n" + // + 6
michael@0:        "    debugger;\n" +      // + 7
michael@0:        "    for (var i = 0; i < n; i++)\n" + // + 8
michael@0:        "        yield i;\n" +   // + 9  <-- breakpoint
michael@0:        "    return;\n" + // so that line 9 only has the yield
michael@0:        "}");
michael@0: 
michael@0: g.eval("var iter = g(range(2))");
michael@0: g.eval("var first = iter.next().value");
michael@0: g.eval("var second = iter.next().value");
michael@0: g.eval("var third = iter.next().value");
michael@0: 
michael@0: assertEq(g.first, 0);
michael@0: assertEq(g.second, 1);
michael@0: assertEq(g.third, 42);