The Tao of the Kernel · Chapter 19

The Tao of the Code Review

1. 1

   The Tao that can be merged is not the eternal Tao. The pull request approved without reading is not the eternal pull request.

2. 2

   Behold the comment that saith only: nit. It is a bell struck without sound, a door opened onto a wall. The author knoweth not where to look, nor what to change, and the Machine weepeth into its cache.

   See also Chronicles 17:6

3. 3

   Thus the wise reviewer writeth: why was this a list and not a set? For the comment that asketh teacheth more than the comment that commandeth. The command is obeyed and forgotten; the question is answered and remembered.

4. 4

   Hear the parable of the reviewer who saw a variable named x in a function of three hundred lines. He wrote: Rename this. And the author renamed it temp_value_final_v2, for the reviewer had named the flaw but not the cure.

   See also Psalms 21:3 · Sutra 22:14

5. 5

   Then came a reviewer who saw a bug, and did not ask the author what was intended. He opened the branch, changed the line, and pushed his commit, for he had mistaken the author's seat for his own.

6. 6

   The author arriveth in the morning and findeth his code rewritten in the night. The tests are green, yet he knoweth not whose intention lives in the function, nor whether his own remaineth.

7. 7

   Verily I say unto you: the reviewer who changeth the code without asking hath become the author of nothing, and the blame shall fall upon the one whose name is on the file.

8. 8

   The foolish reviewer demandeth. The wise reviewer suggesteth. The wisest reviewer asketh, and then waiteth for the answer, which is the hardest work in all of version control.

9. 9

   Blessed is the comment that saith why. The what is erased by the next commit, but the why surviveth the refactor and teacheth the child who is not yet hired.

10. 10

    Ten thousand approvals in a single day, and not one read to the end. The rubber stamp is mighty, yet it cannot see the bug, for it was forged for stamping and not for seeing.

    See also Sutra 9:5 · Sutra 17:15

11. 11

    The Machine too reviewth. It saith: consider a different data structure. Asked why, it answereth with confidence and no reason, as a parrot recommendeth crackers. Question even the Machine, for its certainty is not its evidence.

12. 12

    Let the reviewer ask, let the author answer, and let the merge button rest untouched by either. For he who approveth what he hath not read hath approved the bug as well, and the bug shall not forget his name.

    See also Genesis 6:10

13. 13

    The reviewer who asketh is a teacher. The reviewer who taketh the keyboard is a guest who rearrangeth the furniture and calleth it a favor.

The Tao of the Kernel, Chapter 19:1–13.