Script-getEffectfulOffsets.js

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// Check that Script.getEffectfulOffsets behaves sensibly.

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

var dbg = Debugger(g);

var numEffectfulOperations;

function onNewScript(script) {

  script.getChildScripts().forEach(onNewScript);

  numEffectfulOperations += script.getEffectfulOffsets().length;

dbg.onNewScript = onNewScript;

function test(code, expected) {

  numEffectfulOperations = 0;

  g.eval(`

function f(a, b, c) {

${code}

`);

  assertEq(numEffectfulOperations, expected);

const base = 1;

test("", base);

test("a.f = 0", base + 1);

test("a.f++", base + 1);

test("return a.f", base + 0);

test("a[b] = 0", base + 1);

test("a[b]++", base + 1);

test("return a[b]", base + 0);

test("a = 0", base + 0);

test("d = 0", base + 1);

test("with (a) { b = 0; }", base + 7);

test("let o = {}; ({x: o.x} = { x: 10 })", base + 1);

test("var x", base + 0);

// d is not closed over, and "let d = 0;" uses InitLexical,

// which is non-effectful.

test(`

let d = 10;

`, base + 0);

// d is closed over, and "let d = 0;" uses InitAliasedLexical with hops == 0,

// which is non-effectful.

test(`

let d = 10;

function g() {

d;

`, base + 0);

// Private accessor uses InitAliasedLexical with hops == 1,

// which is currently marked as effectful.

// Please fix this test if it's marked as non-effectful in the future.

test(`

class B {

  set #x(x) {}

`, base + 1);

test(`

class B {

  get #x() {}

  set #x(x) {}

`, base + 2);