🚀 Streamlining Deploys and YAML Quoting
🔧 Today we tackled three interrelated issues in the deploy pipeline and Haskell automation code, each small on its own but collectively making the system more robust and efficient.
🏗️ Problem One: Duplicate Deploy Runs
🤔 The Deploy Quartz site workflow was occasionally running two instances simultaneously. 🔍 The root cause was that the concurrency group was scoped per branch, meaning pushes to different branches each got their own independent deploy pipeline. 🎯 Since only one deployment to GitHub Pages makes sense at any given time, we changed the concurrency group from a branch-specific identifier to a single global group called pages. ✅ Now, any new push anywhere automatically cancels any in-progress deploy, regardless of which branch triggered it.
🦀 Problem Two: Redundant Haskell Build
🏗️ The deploy workflow had its own full Haskell build job just to produce the inject-giscus binary. 🔄 Meanwhile, a separate Haskell CI workflow already builds everything and uploads the binary as an artifact with ninety-day retention. 🗑️ We removed the entire Haskell build job from the deploy workflow. 📦 Instead, we now download the inject-giscus binary from the latest successful Haskell CI run using the GitHub CLI. 🚀 This cuts the deploy pipeline from three jobs to two and eliminates a multi-minute Haskell compilation step.
📝 Problem Three: YAML Quoting in Frontmatter
🐛 The Haskell code that writes YAML frontmatter properties was not quoting values that need it. 🔢 A date like 2026-03-28 would be written unquoted, causing YAML parsers to interpret it as a date type rather than a string. 🔗 URLs containing colons, boolean strings like false, and values with brackets were all written bare. 📐 The BlogImage module already had a well-tested quoteYamlValue function that handles all these cases, but it was defined locally rather than shared.
🏠 We extracted quoteYamlValue into the shared Frontmatter module, where it naturally belongs alongside parseFrontmatter. 🔧 Both InternalLinking and BlogImage now import it from there. 🏗️ The DailyReflection module now uses it for URL and date title values.
🧪 Testing the Fix
✅ We added fifteen test cases for quoteYamlValue covering plain text, empty strings, colons, brackets, booleans, nulls, numeric values, date-like strings, hash comments, internal quotes, backslashes, leading spaces, commas, and curly braces. 🎯 All two hundred sixty tests pass.
📋 Summary of Changes
🔀 Six files changed across the workflow and Haskell codebase.
- 🏗️ deploy.yml lost its entire build-haskell job and gained a lightweight artifact download step
- 🔒 The concurrency group became global rather than per-branch
- 📦 Frontmatter.hs gained the shared quoteYamlValue function
- 🔧 InternalLinking.hs and DailyReflection.hs now properly quote YAML values
- 🗑️ BlogImage.hs removed its local duplicate of quoteYamlValue
- 🧪 FrontmatterTest.hs gained fifteen new test cases
🎓 Lessons Learned
🧩 Small utility functions that handle correctness concerns, like YAML quoting, should live in shared modules from the start. 🔄 When one module has the right implementation and another has the same need, the first refactoring step is extraction to a common location. 🏗️ CI pipelines benefit from the same DRY principle as application code; if another workflow already builds the artifact you need, download it instead of rebuilding.
📚 Book Recommendations
📖 Similar
- 🔧 Release It! by Michael T. Nygard
- 🏗️ Continuous Delivery by Jez Humble and David Farley
🔄 Contrasting
- 🎨 The Design of Everyday Things by Don Norman
- 🧘 Zen and the Art of Motorcycle Maintenance by Robert M. Pirsig
🎭 Creatively Related
- 🧱 A Philosophy of Software Design by John Ousterhout
- 🔬 Working Effectively with Legacy Code by Michael Feathers