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Code Review is an Architectural Necessity - Code Daze Vol. 2; Sep 14, 2018

Colin Dean
September 14, 2018

Code Review is an Architectural Necessity - Code Daze Vol. 2; Sep 14, 2018

Code Review is not a new concept, but a specific term for an older concept -- Peer Review -- that focuses the review process on the code under examination instead of the person who submitted it. While Code Review is common in open source projects, organizations developing in private often employ inefficient, frustrating, or virtually non-existent review processes. This talk looks at Code Review from an architect's viewpoint, arguing that Code Review is an essential component in a product's architectural plan because of the quality attributes it may provide in addition to the knowledge sharing and culture it encourages. It also covers tips and sets expectations for what Code Review can and cannot solve.

This is the third iteration on this presentation. Previous iterations are also available on SpeakerDeck and at https://github.com/colindean/talks/tree/master/code_review.

Colin Dean

September 14, 2018
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Transcript

  1. #codereview Code review is an architectural necessity Colin Dean @colindean

  2. @ColinDean Software Engineer Organizer, Code & Supply Director, Abstractions.io Wearer

    of many hats
  3. #codereview My words are my own and not my employer’s,

    past or present. Please save questions until the end of the presentation.
  4. #codereview Agenda • Quick anecdote • What is code review?

    • What problems does code review solve? • Quality attributes code review ensures • Tips for code reviews • Limitations
  5. #codereview

  6. #codereview Agenda • Quick anecdote • What is code review?

    • What problems does code review solve? • Quality attributes code review ensures • Tips for code reviews • Limitations
  7. #codereview What is code review?

  8. #codereview Code review is the process by which those who

    maintain a software codebase evaluate a proposed change to that codebase, regardless of the source of the proposed change.
  9. #codereview Code review is systematic examination of computer source code.

    Code Review, Wikipedia
  10. #codereview Peer Review

  11. #codereview Code Review

  12. #codereview Code Review Vocabulary • Change - an individual unit

    of work altering what exists • Submission - a collection of changes • Submitter - the person proposing the submission • Reviewer - the people evaluating the submission • Annotation - remarks or ratings bestowed upon the submission
  13. #codereview The submitter proposes changes in a submission, which is

    evaluated by a reviewer, who annotates or accepts it.
  14. Inspection Team review Walkthrough Pair programming Peer deskcheck, passaround Ad-hoc

    review Wiegers’ peer review formality spectrum Least formal Most formal
  15. Most formal Least formal Wiegers’ peer review formality spectrum Inspection

    Team review Walkthrough Pair programming Peer deskcheck, passaround Ad-hoc review
  16. None
  17. #codereview Agenda • Quick anecdote • What is code review?

    • What problems does code review solve? • Quality attributes code review ensures • Tips for code reviews • Limitations
  18. #codereview Code review solves two major problems. Aside from the

    primary goal of reducing defects,
  19. #codereview Mental model synchronization Code review solves

  20. None
  21. None
  22. Close enough Needs guidance On target

  23. Alternative
 solutions New idea Open to
 new idea

  24. #codereview Tribal knowledge development Code review solves

  25. #codereview Michael Keeling
 Creating an Architecture Oral History, SATURN 2012

    “Architecture oral history requires that the team is both willing and able to retell the stories and keep the oral history alive.”
  26. #codereview Application code Code review audits

  27. #codereview Application infrastructure Code review audits

  28. #codereview Application architecture Code review audits

  29. #codereview Write it down. Make it searchable. Code review forces

    us to
  30. #codereview Agenda • Quick anecdote • What is code review?

    • What problems does code review solve? • Quality attributes code review ensures • Tips for code reviews • Limitations
  31. #codereview Maintainability Code review ensures

  32. #codereview Maintainability • Learnability • Understandability • Serviceability Code review

    drives
  33. #codereview Learnability • Developing Code • Patterns & Conventions •

    Risks & Goals • Developing People • Common Vocabulary • Teaching Moments Understandability Serviceability Code review drives Maintainability Learnability
  34. Learner Expert Coding Reviewing Coding Reviewing Synchronous Pairing & Teaching

    Exemplary Reading Constructively Critical Evaluation Serendipitous Evaluation of Example Understandability Serviceability Maintainability Learnability
  35. #codereview Understandability • Establishes common yet evolving mental model •

    Builds confidence in direction and design decisions • Builds tribal knowledge • Bonus: Enables elevator pitch Serviceability Code review drives Maintainability Learnability Understandability
  36. #codereview Serviceability • Exposes addressable “gotchas” • Exposes end-user interaction

    points • Establishes consensus on supported workflows Maintainability Learnability Understandability Serviceability Code review drives
  37. #codereview Linus’s Law “Given enough eyes, all bugs are shallow.”

  38. #codereview Maintainability ✓Learnability ✓Understandability ✓Serviceability Code review drives

  39. #codereview First programming job out of school - B2B imprinting

    company if($customer == “spacely_sprockets”) { do_something(); }
 else { cry(); } • Version control! • No code review tooling or process • Minimal pairing • Continuous integration easily circumvented
  40. #codereview Lack of code review Lost Opportunities

  41. #codereview Lack of code review Lost Opportunities Lost Revenue

  42. #codereview Lack of code review Lost Opportunities Lost Revenue Lost

    Job
  43. #codereview Compliance Code review ensures

  44. #codereview Compliance • Accessibility • Auditability • Idiomaticity Code review

    drives
  45. #codereview Second job out of school - Consulting • Lone

    wolf working alongside other lone wolves • No version control in proprietary software with custom “IDE” a.k.a. textarea. • Last modified and modifier only • No process of our own
  46. First professional code review experience was group review • Subcontractor

    on government project, 2010-2012 • Lone SME on platform • Borland StarTeam + in house review system • My tools for version control integration • Weekly merge window • Round robin inspection
  47. None
  48. #codereview Not a pleasant experience • Three to four hour

    weekly round robin inspection • Cutthroat mixture of competing contractors, subcontractors, and employees • Embarrassment galore ‛ Not a learning environment • Immediate defensive posture • “Merge next week” = you failed, possibly delayed project
  49. #codereview $1,450 per hour

  50. #codereview $1,450 per hour $5,800 per weekly meeting

  51. #codereview $1,450 per hour $5,800 per weekly meeting $290,000 per

    year
  52. #codereview Effects? • Waste • “Get this over with.” •

    Obstructionism • Plenty of bugs • “I’ll fix that mistake later.”
  53. #codereview Missed opportunities • Accessibility expert was most vocal •

    Project manager was vocal on contractual and HF matters ➡ Both could have reviewed asynchronously • Project was behind ➡ Too many people could say No
  54. #codereview Security Code review ensures

  55. #codereview Security • Spot vulnerabilities • Teach best practices •

    Filter unnecessary code • YAGNI Code review drives
  56. #codereview Reviewers are like your lawyer Screening and recommending actions

    to minimize risk, avoid preventable mistakes
  57. #codereview Agenda • Quick anecdote • What is code review?

    • What problems does code review solve? • Quality attributes code review ensures • Tips for code reviews • Limitations
  58. #codereview When should you integrate code review?

  59. #codereview Context • Project • Technical

  60. #codereview Keep reviews informal and short.

  61. #codereview Tips for thorough code review • Devote time •

    Accept debt • Identify churn • Minimize pedantry • Make progress
  62. #codereview Major things we look for • Algorithmic complexity •

    Exception & error handling • Exception, class, & variable naming • Logging sufficiency & level • Style conformation (automate!) • Long lines & methods • Readability • Single purpose per commit
  63. #codereview Most importantly Does it work? Is it tested?

  64. #codereview Agenda • Quick anecdote • What is code review?

    • What problems does code review solve? • Quality attributes code review ensures • Tips for code reviews • Limitations
  65. #codereview Analyze dynamic structures Code review cannot

  66. #codereview Go on endlessly Code review cannot

  67. #codereview Solve political problems Code review cannot

  68. #codereview Agenda • Quick anecdote • What is code review?

    • What problems do code review solve? • Quality attributes code review ensures • Tips for code reviews • Limitations
  69. #codereview

  70. #codereview Code Review is systematic examination of proposed changes to

    a codebase. solves mental model synchronization and tribal knowledge development. ensures maintainability, compliance, & security. must be short, thorough, and automated where possible. will not solve all human problems, but some is better than none.
  71. #codereview codeandsupply.co the folks behind @codeandsupply codeandsupply.fund

  72. @ColinDean github.com/
 colindean/talks speakerdeck.com/ colindean

  73. #codereview –Johnny Appleseed FINITA (that’s Esperanto for “finished”)

  74. #codereview Attributions • Westminster College picture: https://www.flickr.com/photos/westminstercollege/15759678054/in/ album-72157649340620016/ • “Their

    first code review” http://classicprogrammerpaintings.tumblr.com/post/142702963264/their-first-code-review- william-frederick • Bass, Len; Paul Clements, and Rick Kazman. Software Architecture in Practice. Addison Wesley, 2013. • Wiegers, Karl E. Peer Reviews in Software. Addison Wesley, 2012. • Cohen, Jason, Steven Teleki, and Eric Brown. Best Kept Secrets of Peer Code Review. Smart Bear Software, 2006. • Wilhelm, Alex and Alexia Tsotsis. Julie Ann Horvath Describes Sexism and Intimidation behind Her Github Exit. TechCruch, 2014 March 15. Retrieved 2016 April 26. http://techcrunch.com/2014/03/15/julie-ann-horvath- describes-sexism-and-intimidation-behind-her-github-exit/ • Baccehlli, Alberto and Christian Bird. Expectations, Outcomes, and Challenges Of Modern Code Review. Proceedings of the International Conference on Software Engineering, Proceedings of the International Conference on Software Engineering, May 2013. • Social media icons from FontAwesome • and others mentioned in the slides
  75. #codereview No, really. Fin. Srsly. Ne, reale. Finita. Serioze.