stepping.js - mozsearch

Enable keyboard shortcuts

// Test that stepping through a function stops at the expected lines.

// `script` is a string, some JS code that evaluates to a function.

// `expected` is the array of line numbers where stepping is expected to stop

// when we call the function.

function testStepping(script, expected) {

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

    let f = g.eval(script);

    let log = [];

    function maybePause(frame) {

        let previousLine = log[log.length - 1]; // note: may be undefined

        let line = frame.script.getOffsetLocation(frame.offset).lineNumber;

        if (line !== previousLine)

            log.push(line);

    let dbg = new Debugger(g);

    dbg.onEnterFrame = frame => {

        // Log this pause (before the first instruction of the function).

        maybePause(frame);

        // Log future pauses in the same stack frame.

        frame.onStep = function() { maybePause(this); };

        // Now disable this hook so that we step over function calls, not into them.

        dbg.onEnterFrame = undefined;

};

    f();

    assertEq(log.join(","), expected.join(","));