Clear the Lineup — doesNotEqual was always true for single-select survey answers in Formbricks

This is a submission for DEV's Summer Bug Smash: Clear the Lineup . Project Overview Formbricks is an open-source survey and experience-management platform. Its packages/surveys package ships the client-side survey runner, and inside it, packages/surveys/src/lib/logic.ts is the module that decides, for every question and every "skip logic" / branching rule a survey author configures, whether a given condition ( equals , doesNotEqual , contains , isEmpty , and friends) is true for a respondent's answer. This is pure, unglamorous logic — but it's load-bearing: it's what routes respondents through the correct sequence of questions. I picked up issue #8527 for the "Clear the Lineup" track, which reports that doesNotEqual conditions weren't behaving correctly for single-choice questions. Bug Fix or Performance Improvement The doesNotEqual operator is supposed to be the exact logical negation of equals . For most answer shapes it was. But for MultipleChoiceSingle answers, the survey runtime sometimes represents the selected value as a single-element array rather than a bare string (this happens via getLeftOperandValue , e.g. when a choice answer is merged with an "other" option path). To handle that shape, both equals and doesNotEqual had a special-case clause that unwraps a one-element array and compares its only entry to the right-hand value. equals 's fallback: return ( ( Array . isArray ( leftValue ) && leftValue . length === 1 && typeof rightValue === " string " && leftValue . includes ( rightValue )) || leftValue === rightValue ); doesNotEqual 's fallback (before the fix): return ( ( Array . isArray ( leftValue ) && leftValue . length === 1 && typeof rightValue === " string " && ! leftValue . includes ( rightValue )) || leftValue !== rightValue ); At a glance this looks like a faithful "negate every sub-expression" mirror of equals . It isn't. The array-includes clause was correctly inverted ( !leftValue.includes(rightValue) ), but the second disjunct, leftValue !==