René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"bug: JSON literals are accepted as numeric survey prefill values","articleBody":"## Issue\n\nNumeric survey prefill parsing currently accepts JSON literals like `true`, `false`, and `null` as numbers.\n\nExamples:\n\n```text\n?npsQuestionId=true\n?ratingQuestionId=true\n?npsQuestionId=null\n```\n\nCurrent behavior:\n\n- `parseNumber(\"true\")` returns `1`\n- `parseNumber(\"false\")` returns `0`\n- `parseNumber(\"null\")` returns `0`\n- NPS/rating validators can then accept those coerced values as valid numeric prefill answers\n\nExpected behavior: numeric prefill values should only accept actual parsed numbers. JSON booleans/null should be rejected and ignored as invalid prefill values.\n\n## Impact\n\nMalformed or incorrectly generated survey links can silently prefill real NPS/rating answers with unintended values instead of being ignored.\n\n## Fix\n\n`parseNumber` now accepts only finite parsed JSON numbers, avoiding `Number(...)` coercion of booleans/null.\n\n## Tests\n\nAdded regression coverage for:\n\n- `parseNumber(\"true\")`, `parseNumber(\"false\")`, and `parseNumber(\"null\")`\n- `validateNPS(\"true\")` / `validateNPS(\"null\")`\n- `validateRating(..., \"true\")` / `validateRating(..., \"null\")`\n\nVerified:\n\n```bash\ngit diff --check\npnpm vitest run apps/web/modules/survey/link/lib/prefill/parsers.test.ts apps/web/modules/survey/link/lib/prefill/validators.test.ts\npnpm --filter @formbricks/web exec eslint modules/survey/link/lib/prefill/parsers.ts modules/survey/link/lib/prefill/parsers.test.ts modules/survey/link/lib/prefill/validators.test.ts\n```\n\nBranch: https://github.com/bharathkumar39293/formbricks/tree/fix/reject-json-literals-prefill-number\n\nSince PR creation is restricted for contributors, I’m happy to open a PR if access is granted, or a maintainer can cherry-pick the commit.","author":{"url":"https://github.com/bharathkumar39293","@type":"Person","name":"bharathkumar39293"},"datePublished":"2026-06-02T10:01:47.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":3},"url":"https://github.com/8213/formbricks/issues/8213"}