• There are 386 files with units, with 34,684 lines of code.
• 0 very complex files (McCabe index sum 251+; 0 lines of code)
• 0 complex files (McCabe index sum 126-250; 0 lines of code)
• 9 medium complex files (McCabe index sum 51-125; 5,086 lines of code)
• 22 slightly complex files (McCabe index sum 26-50; 4,681 lines of code)
• 355 simple files (McCabe index sum 1-25; 24,917 lines of code)
• 246 main files have no units (e.g. languages without unit analysis, or files without functions) and are not classified.

The McCabe index of a file grows with its size: per 100 lines tells a large but plain file from a dense one, and most complex unit whether the complexity sits in one unit or is spread over many.

File	# lines	# units	McCabe index (sum)	per 100 lines	most complex unit
Neo4jAnnotations.scala in backend/app/services/annotations	708	28	118	17	33
Neo4jManifest.scala in backend/app/services/manifest	1206	44	89	7	8
HitReaders.scala in backend/app/services/index	324	29	76	23	10
ElasticsearchResources.scala in backend/app/services/index	940	32	70	7	7
TranscriptionWorkerInterfaceGenerator.scala in project	297	15	70	24	13
Workspaces.scala in backend/app/controllers/api	394	28	66	17	5
UploadFiles.tsx in frontend/src/js/components/Uploads	458	17	63	14	18
Viewer.tsx in frontend/src/js/components/viewer	362	10	59	16	19
Neo4jUserManagement.scala in backend/app/services/users	397	24	54	14	6
Workspaces.tsx in frontend/src/js/components/workspace	1364	17	49	4	16
ErrorFormatter.scala in cli/src/main/scala/com/gu/pfi/cli	78	3	49	63	27
Ocr.scala in backend/app/utils	244	7	48	20	24
WorkerControl.scala in backend/app/utils	217	17	47	22	12
resourceUtils.ts in frontend/src/js/util	154	15	46	30	9
FailureToResultMapper.scala in backend/app/utils/controller	154	4	45	29	40
ExternalTranscriptionWorker.scala in backend/app/extraction	257	13	45	18	15
Neo4jHelper.scala in backend/app/utils	255	23	43	17	7
Search.scala in backend/app/controllers/api	159	11	42	26	10
PreviewService.scala in backend/app/services/previewing	137	13	42	31	10
Attempt.scala in common/src/main/scala/utils/attempt	135	20	42	31	5
Collections.scala in backend/app/controllers/api	241	15	40	17	6
CommandValidator.scala in cli/src/main/scala/com/gu/pfi/cli	107	8	37	35	8
ExcelTableExtractor.scala in backend/app/extraction/tables	129	5	36	28	9
CliHttpClient.scala in cli/src/main/scala/com/gu/pfi/cli/service	147	12	31	21	7
HtmlToPlainText.scala in backend/app/utils	93	5	30	32	10
Email.scala in backend/app/model	178	8	30	17	10
Chip.scala in backend/app/model/frontend	93	3	29	31	17
pageViewerApi.ts in frontend/src/js/components/viewer/PageViewer	103	17	27	26	3
CommentHighlighter.tsx in frontend/src/js/components/viewer	143	5	27	19	10
GetResource.scala in backend/app/commands	128	6	27	21	7
IngestStorePolling.scala in backend/app/ingestion/phase2	165	8	26	16	9
parseDate.ts in frontend/src/js/util	112	6	25	22	16
EmlParser.scala in backend/app/extraction/email/eml	126	8	25	20	11
Preview.tsx in frontend/src/js/components/viewer	137	3	24	18	21
AwsDiscovery.scala in backend/app/utils	226	9	24	11	6
IngestionServices.scala in backend/app/services/ingestion	178	11	24	13	8
Models.scala in backend/app/services/observability	184	9	24	13	5
HighlightFields.scala in backend/app/services/index	112	9	24	21	8
workspaceUtils.ts in frontend/src/js/util	117	7	23	20	7
workspaceNavigation.ts in frontend/src/js/util	136	6	23	17	8
Users.scala in backend/app/controllers/api	111	10	23	21	4
Blobs.scala in backend/app/controllers/api	122	7	23	19	6
PagesController.scala in backend/app/controllers/api	141	9	23	16	5
treeUtils.ts in frontend/src/js/util	127	10	22	17	6
CommentPanel.tsx in frontend/src/js/components/viewer/CommentPanel	279	6	22	8	10
WorkspaceApi.ts in frontend/src/js/services	228	21	22	10	2
Resource.scala in backend/app/model/frontend	170	8	22	13	7
Worker.scala in backend/app/extraction	153	7	22	14	8
ElasticsearchSyntax.scala in backend/app/services	126	11	22	17	4
TreeEntry.scala in backend/app/model/frontend	76	4	21	28	7

• File complexity is the sum of the McCabe indexes (conditional complexity) of the units (methods, functions...) in a file.
• Files are classified in five categories based on that sum: 1-25 (simple files), 26-50 (slightly complex files), 51-125 (medium complex files), 126-250 (complex files), 251+ (very complex files). The default bands are five times the unit complexity bands, as a file is a group of units.
• Only main code files with units are classified. Files without units (languages without unit analysis, or files without functions) have no complexity to measure and are left out rather than counted as simple.
• A very complex file holds many decisions, which often means it has too many responsibilities: a candidate to split, and a place where changes need more testing.