guardian/scala-school-json-workshop

0.01K

scala

Rule-of-thumb estimates

Rebuild value

lines of main code per man-year per man-year currency

to rebuild

rebuild value

Maintenance effort

% of the rebuild value per year

per year to maintain

maintenance cost per year

Rules of thumb, not measurements: one man-year rebuilds about 10,000 lines of main code (design, testing and coordination included), and keeping a code base alive takes about 15% of its rebuild value per year (20 man-years of rebuild value need about 3 man-years of maintenance every year). Your changes are remembered in this browser for every report.

Ease of change*

10.0ABCDE

for people · measured on 4 of 10 sub-scores

Ease of change*

10.0ABCDE

for AI · measured on 4 of 9 sub-scores

Duplication

0%good

of main code duplicated

Large files

0%good

of main code in files > 500 lines

Goals

4 / 4good

controls in range

Ease of change*

How easily the code can be understood and changed, from 0 to 10. Other things equal, less code is easier and cheaper to change, for people and for agents. Both ratings weigh the same sub-scores: people struggle most with complex logic and knowledge held by few; agents pay for every line they read, copy duplicates and need tests to check their work. The total is a weighted geometric mean; above the weakest code sub-score + 4 only half of it counts, so one weak spot is not averaged away. Sub-scores are ordered by drag, how much the uncapped mean would rise if that sub-score were 10; click one to see why it matters. * A heuristic: compare repositories rather than read it as absolute. Set weights, or your own framework, in analysis.maintainabilityScores.

Human10.0ABCDE

Measured on 4 of 10 sub-scores (not measured: Unit size, Unit complexity, File complexity, Change entropy, Context per change, Knowledge spread).

Volume10.0×15 lines of main code
For people: More code is more to learn, search and keep in mind; onboarding and judging a change's impact slow down as it grows.
For AI agents: An agent sees only a slice at a time: the bigger the code base, the more it searches, and the likelier it misses relevant code or rewrites an existing helper.
Duplication10.0×10% of main code duplicated
For people: A fix in one copy must be repeated in all the others; a missed copy becomes a bug.
For AI agents: Agents copy the patterns they find, so duplicates multiply; a change to one copy misses the others, and every copy costs context.
File size10.0×0.750% of main code in files > 500 lines
For people: Large files are hard to navigate, mix responsibilities and attract merge conflicts.
For AI agents: Agents read whole files into their context: every change to a large file costs many tokens and crowds out other relevant code.
Tests presence10.0×0.75300 test lines per 100 main lines
For people: A test suite documents the intended behaviour and makes changes safe. Counted is whether there is one of reasonable size, not its coverage.
For AI agents: Tests let an agent check its own work; without them its mistakes surface later, in review or in production.

AI10.0ABCDE

Measured on 4 of 9 sub-scores (not measured: Unit size, Unit complexity, File complexity, Change entropy, Context per change).

Volume10.0×0.755 lines of main code
For AI agents: An agent sees only a slice at a time: the bigger the code base, the more it searches, and the likelier it misses relevant code or rewrites an existing helper.
For people: More code is more to learn, search and keep in mind; onboarding and judging a change's impact slow down as it grows.
Duplication10.0×1.50% of main code duplicated
For AI agents: Agents copy the patterns they find, so duplicates multiply; a change to one copy misses the others, and every copy costs context.
For people: A fix in one copy must be repeated in all the others; a missed copy becomes a bug.
File size10.0×1.750% of main code in files > 500 lines
For AI agents: Agents read whole files into their context: every change to a large file costs many tokens and crowds out other relevant code.
For people: Large files are hard to navigate, mix responsibilities and attract merge conflicts.
Tests presence10.0×1.5300 test lines per 100 main lines
For AI agents: Tests let an agent check its own work; without them its mistakes surface later, in review or in production.
For people: A test suite documents the intended behaviour and makes changes safe. Counted is whether there is one of reasonable size, not its coverage.

Where to look first

The most complex main files (no git history, so no change frequency).

1
Article.scala
src/main/scala/example/model/
3 LOC
2
Tag.scala
src/main/scala/example/model/
2 LOC

Explore all files →

Standard analyses:
		Main Code: 5 LOC (2 files) = SCALA (100%) Secondary code: Test: 15 LOC (1); Generated: 0 LOC (0); Build & Deploy: 48 LOC (3); Other: 15 LOC (2);
		Duplication: 0%
		File Size: 0% long (>1000 LOC), 100% short (<= 200 LOC)
		Logical Component Decomposition: primary (1 component)
		Goals: Keep the system simple and easy to change (4)

Experimental analyses (less reliable heuristic analyses):
		Static Component Dependencies: primary (1 component)