/**
 * Test the behavior of very, very long regex patterns.
 */
(function() {
"use strict";

const coll = db.regex_limit;
coll.drop();

const kMaxRegexPatternLen = 32761;

// Populate the collection with a document containing a very long string.
assert.commandWorked(coll.insert({z: "c".repeat(100000)}));

// Test that a regex exactly at the maximum allowable pattern length can find a document.
const patternMaxLen = "c".repeat(kMaxRegexPatternLen);
assert.eq(1, coll.find({z: {$regex: patternMaxLen}}).itcount());
assert.eq(1, coll.find({z: {$in: [new RegExp(patternMaxLen)]}}).itcount());

// Test that a regex pattern exceeding the limit fails.
const patternTooLong = "c".repeat(kMaxRegexPatternLen + 1);
assert.commandFailedWithCode(coll.runCommand("find", {filter: {z: {$regex: patternTooLong}}}),
                             51091);
assert.commandFailedWithCode(
    coll.runCommand("find", {filter: {z: {$in: [new RegExp(patternTooLong)]}}}), 51091);
}());