breakpoint-11.js - mozsearch

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// Setting a breakpoint in a generator function works, and we can

// traverse the stack and evaluate expressions in the context of older

// generator frames.

var g = newGlobal({newCompartment: true});

var dbg = Debugger(g);

dbg.onDebuggerStatement = function (frame) {

    function hit(frame) {

        frame.older.eval("q += 16");

    var s = frame.script;

    var offs = s.getLineOffsets(g.line0 + 9);

    for (var i = 0; i < offs.length; i++)

        s.setBreakpoint(offs[i], {hit: hit});

};

g.eval("line0 = Error().lineNumber;\n" +

       "function* g(x) {\n" +   // + 1

       "    var q = 10;\n" +    // + 2

       "    yield* x;\n" +      // + 3

       "    return q;\n" +      // + 4

       "}\n" +                  // + 5

       "function* range(n) {\n" + // + 6

       "    debugger;\n" +      // + 7

       "    for (var i = 0; i < n; i++)\n" + // + 8

       "        yield i;\n" +   // + 9  <-- breakpoint

       "    return;\n" + // so that line 9 only has the yield

       "}");

g.eval("var iter = g(range(2))");

g.eval("var first = iter.next().value");

g.eval("var second = iter.next().value");

g.eval("var third = iter.next().value");

assertEq(g.first, 0);

assertEq(g.second, 1);

assertEq(g.third, 42);