'use strict';

const common = require('../common');

const ArrayStream = require('../common/arraystream');

const { describe, it } = require('node:test');

const assert = require('assert');

const repl = require('repl');

function prepareREPL() {

const input = new ArrayStream();

const replServer = repl.start({

prompt: '',

input,

output: process.stdout,

allowBlockingCompletions: true,

});

// Some errors are passed to the domain, but do not callback

replServer._domain.on('error', assert.ifError);

return { replServer, input };

}

function getNoResultsFunction() {

return common.mustSucceed((data) => {

assert.deepStrictEqual(data[0], []);

});

}

describe('REPL tab completion without side effects', () => {

const setup = [

'globalThis.counter = 0;',

'function incCounter() { return counter++; }',

'const arr = [{ bar: "baz" }];',

];

// None of these expressions should affect the value of `counter`

for (const code of [

'incCounter().',

'a=(counter+=1).foo.',

'a=(counter++).foo.',

'for((counter)of[1])foo.',

'for((counter)in{1:1})foo.',

'arr[incCounter()].b',

]) {

it(`does not evaluate with side effects (${code})`, async () => {

const { replServer, input } = prepareREPL();

input.run(setup);

replServer.complete(code, getNoResultsFunction());

assert.strictEqual(replServer.context.counter, 0);

replServer.close();

});

}

});