Environment-variables.js

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// Comprehensive test of get/setVariable on many kinds of environments and

// bindings.

load(libdir + "asserts.js");

var cases = [

    // global bindings and bindings on the global prototype chain

    "x = VAL; @@",

    "var x = VAL; @@",

    "Object.prototype.x = VAL; @@",

    // let and catch bindings

    "let x = VAL; @@",

    "{ let x = VAL; @@ }",

    "try { throw VAL; } catch (x) { @@ }",

    "try { throw VAL; } catch (x) { @@ }",

    "for (let x of [VAL]) { @@ }",

    "switch (0) { default: let x = VAL; @@ }",

    // arguments

    "function f(x) { @@ } f(VAL);",

    "function f([w, x]) { @@ } f([0, VAL]);",

    "function f({v: x}) { @@ } f({v: VAL});",

    "function f([w, {v: x}]) { @@ } f([0, {v: VAL}]);",

    // bindings in functions

    "function f() { var x = VAL; @@ } f();",

    "function f() { let x = VAL; @@ } f();",

    "function f() { function x() {} x = VAL; @@ } f();",

    // dynamic bindings

    "function f(s) { eval(s); @@ } f('var x = VAL');",

    "var x = VAL; function f(s) { eval('var x = 0;'); eval(s); @@ } f('delete x;');",

    "function f(obj) { with (obj) { @@ } } f({x: VAL});",

    "function f(obj) { with (obj) { @@ } } f(Object.create({x: VAL}));",

    "function f(b) { if (b) { function x(){} } x = VAL; @@ } f(1);",

];

var nextval = 1000;

function test(code, debugStmts, followupStmts) {

    var val = nextval++;

    var hits = 0;

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

    g.eval("function debugMe() { var x = 'wrong-x'; eval(\"\"); debugger; }");

    g.capture = null;

    var dbg = Debugger(g);

    dbg.onDebuggerStatement = function (frame) {

        if (frame.callee !== null && frame.callee.name == 'debugMe')

            frame = frame.older;

        var env = frame.environment.find("x");

        assertEq(env.getVariable("x"), val)

        assertEq(env.setVariable("x", 'ok'), undefined);

        assertEq(env.getVariable("x"), 'ok');

        // setVariable cannot create new variables.

        assertThrowsInstanceOf(function () { env.setVariable("newVar", 0); }, TypeError);

        hits++;

};

    code = code.replace("@@", debugStmts);

    if (followupStmts !== undefined)

        code += " " + followupStmts;

    code = code.replace(/VAL/g, String(val));

    g.eval(code);

    assertEq(hits, 1);

for (var s of cases) {

    // Test triggering the debugger right in the scope in which x is bound.

    test(s, "eval(\"\"); debugger; assertEq(x, 'ok');");

    // Test calling a function that triggers the debugger.

    test(s, "debugMe(); assertEq(x, 'ok');");

    // Test triggering the debugger from a scope nested in x's scope.

    test(s, "{ let y = 'irrelevant'; (function (z) { { let zz = y; eval(\"\"); debugger; } })(); } assertEq(x, 'ok');"),

    // Test closing over the variable and triggering the debugger later, after

    // leaving the variable's scope.

    test(s, "capture = {dbg: function () { eval(\"\"); debugger; }, get x() { return x; }};",

            "assertEq(capture.x, VAL); capture.dbg(); assertEq(capture.x, 'ok');");