COMPLEXITY_INCREASED

Severity: warn (default) / error (new value crosses the error threshold)

A POU's cyclomatic complexity rose between the before and after trees. Complexity is McCabe's count adapted for ST: 1, plus 1 for each IF, ELSIF, FOR, WHILE, REPEAT, each CASE arm, and each AND / OR in a condition.

Why it matters. A POU that gains many decision points in one PR is harder to test and review than the diff line count suggests. Catching the jump on the PR keeps complexity from creeping up unnoticed.

Settings. Reads metrics.thresholds.cyclomatic_complexity from .plc-st-review.yml:

metrics:
  thresholds:
    cyclomatic_complexity:
      warn: 15
      error: 25

Warns on any increase greater than 5. Escalates to error when the new value reaches the error band and the old value was below it (a freshly crossed threshold). Smaller increases that stay below both bars are not reported.

Trigger.

(* before: complexity 8 *)
(* after: an added ELSIF chain pushes it to 31 *)

The bot posts.

🟥 error  COMPLEXITY_INCREASED
FB_MainSequence cyclomatic complexity: 22 → 31 (crossed error threshold of 25)

Fix. Extract the new branching into a method, replace a long IF/ELSIF ladder with a CASE, or split the POU. If the growth is justified, raise the threshold or suppress per-file.