--- title: When False is True | daily.dev description: A Ruby on Rails API had a helper method `param_true?` that incorrectly treated boolean `false` as truthy. The bug stemmed from using `!param_value` in the... canonical: https://daily.dev/posts/when-false-is-true-vggursu5x twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: When False is True | daily.dev og:description: A Ruby on Rails API had a helper method `param_true?` that incorrectly treated boolean `false` as truthy. The bug stemmed from using `!param_value` in the... og:url: https://daily.dev/posts/when-false-is-true-vggursu5x og:image: https://api.daily.dev/og/posts/VGguRsU5X.png og:image:alt: When False is True og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # When False is True **[The Daily WTF](https://daily.dev/sources/thedailywtf)** · 2 min read · 0 upvotes · 0 comments ## Summary A Ruby on Rails API had a helper method `param_true?` that incorrectly treated boolean `false` as truthy. The bug stemmed from using `!param_value` in the condition, which evaluates to `true` when the value is the boolean `false`. The issue went unnoticed because the `dry_run` flag was only ever sent via GET requests (where values are strings), but broke when a new tool sent JSON body parameters with actual boolean values in POST/PATCH/PUT requests. A secondary annoyance is that the method fetches the value before checking if the key exists, which is harmless but stylistically poor. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [AAYFN](https://daily.dev/posts/aayfn-nhv65a6k6) · The Daily WTF · 0 upvotes · 0 comments - [How Rails Builds \`params\` Before Your Action Runs](https://daily.dev/posts/how-rails-builds-params-before-your-action-runs-dli8lx1xl) · Ruby Flow · 2 upvotes · 0 comments - [Explicit query: and body: kwargs for integration tests and more\!](https://daily.dev/posts/explicit-query-and-body-kwargs-for-integration-tests-and-more--vhhwxkt6s) · This Week in Rails · 0 upvotes · 0 comments --- Tags: [#ruby](https://daily.dev/tags/ruby), [#rails](https://daily.dev/tags/rails) [View this post on daily.dev](https://daily.dev/posts/when-false-is-true-vggursu5x) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"When False is True","url":"https://daily.dev/posts/when-false-is-true-vggursu5x","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/when-false-is-true-vggursu5x"},"datePublished":"2026-06-22T11:01:11.608Z","dateModified":"2026-06-22T11:01:27.772Z","description":"A Ruby on Rails API had a helper method `param_true?` that incorrectly treated boolean `false` as truthy. 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